in this issue editor’s corner - earth observing system · in this issue ... meeting/workshop...

Ear

thObserving System

THE EARTH OBSERVER

May/June 2003, Vol. 15, No. 3

In this issue ...Meeting/Workshop Summaries

Minutes of the March 2003 Aura ScienceTeam Meeting ................................ 3

CERES Science Team Meeting ......... 9

CloudSat/CALIPSO Science TeamMeeting Summary ....................... 14

ASTER Users Workshop ................. 17SEEDS Update ................................ 23

Other Items of Interest

CCSDS Lossless Data Compression tobe Available in HDF-4 and 5 ....... 19

Aqua Mission Sponsors 2003 Engineer-ing Competition ........................ 21

Kudos ................................................ 24Earth’s Hidden Waters Tracked by

GRACE .................................... 25NASA’s ESE Sponsors Creative Problem

Solving competition ................. 30

Regular Features

Earth Science Education ProgramUpdate ......................................... 31

EOS Scientists in the News ............. 32

Science Calendars ............................ 33

The Earth Observer Information/Inquiries ........................ Back Cover

Continued on page 2

EDITOR’S CORNER

Michael King

EOS Senior Project Scientist

I’m proud to announce that the International Academy of the Digital Artsand Sciences has selected two NASA Web sites for top honors in theirrespective categories. The NASA Home Page (at www.nasa.gov), managedby Brian Dunbar and his team at NASA Headquarters in Washington, D.C.,won the Webby in the “Government & Law” category. And NASA’s EarthObservatory (at earthobservatory.nasa.gov), managed by David Herring andhis team at Goddard Space Flight Center in Greenbelt, MD, won the Webbyin the “Education” category.

Additionally, both sites won “People’s Voice Awards” for their respectivecategories. In keeping with the spirit of the Web’s capacity for globalinteractivity, the People’s Voice Award is determined by a popular vote inwhich anyone in the world can vote for their favorites in each of theWebby’s thirty categories.

The Webby is the most coveted award by the on-line community (visitwww.webbyawards.com for details). Congratulations to the developmentteams for these two outstanding internet resources, and be sure to checkthem regularly for new informative and stimulating content.

On a somewhat less celebratory note, the Landsat 7 mission is experiencinga problem with the Enhanced Thematic Mapper + (ETM+) multi-spectralscanning instrument. On May 31 the scan line corrector for the instrumentencountered an anomaly, and operations have been halted pending aresolution. The scan line corrector adjusts the line-of-sight of the ETM+,tracing contiguous scan lines orthogonal to the satellite’s path. Without thescan line corrector, the ETM+ scan mirror traces a zig-zag pattern across thefield-of-view resulting in gaps between scan lines.

THE EARTH OBSERVER • May/June 2003 Vol. 15 No. 3

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An anomaly tiger team, comprised ofengineers from NASA, USGS, and theETM+ manufacturer, Santa BarbaraRemote Sensing, is investigating thecause before taking any action to restartthe scan line corrector.

The Landsat series of satellites has beena keystone in land remote sensing sincethe original Earth Resources Technol-ogy Satellite (ERTS-1) was launched inJuly of 1972. The second generation ofLandsat satellites began with thelaunch of Landsat 4 in 1982, whichcarried the new Thematic Mapper (TM)

instrument, with greater spatial andspectral resolution than MSS. ETM+was launched on Landsat 7, and iscapable of even greater resolution. As aresult, the Landsat series of satelliteshas produced an extremely valuablecontinuous data record of the Earth’sland surface and coastal regions forover 30 years.

There will be a special Earth Showcasepress conference in July that will focuson wildfire monitoring by NASA Earthobserving satellites. EOS investigatorChris Justice at the University of

Maryland, the MODIS Rapid ResponseTeam, members of U.S. Forest Serviceand NASA will participate in this“Meet the Press” event. The animationon wildfires produced by the ScientificVisualization Studio at Goddard SpaceFlight Center will be featured at thisevent. This is just one of several Earthscience applications programs devel-oped within the Enterprise, anddemonstrates the real socio-economicbenefits of NASA’s Earth scienceprogram.

This image of Mt. Everest (center, circled) was acquired by Landsat 7’s Enhanced Thematic Mapper plus (ETM+) sensor on January 5, 2002. On May 29,1953, Edmund Hillary, from New Zealand, and Tenzing Norgay, from Nepal, became the first humans to successfully climb to the peak of Mt. Everest, thetallest mountain in the world. Data for this image was provided by the Landsat 7 Team at NASA’s Goddard Space Flight Center.

THE EARTH OBSERVER • May/June 2003 Vol. 15, No. 3

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Minutes of the March 2003 Aura Science Team Meeting

— Anne Douglass, [email protected], Deputy Aura Project Scientist, NASA Goddard Space Flight Center

An Aura Science Team meeting washeld March 18 – 21, 2003 in Greenbelt,MD. Four of the working groups(validation, data systems, aerosols, andeducation and outreach) met on March18, and the full science team convenedMarch 19-21. The Aura ProjectManager, Rick Pickering, provided anoverview of the status of Aura,stressing that Aura integration contin-ues to benefit from experience withAqua. The project remains focused ona launch date in January 2004. As ofthe March meeting, three of the fourinstruments, the Ozone MonitoringInstrument (OMI), High ResolutionDynamics Limb Sounder (HIRDLS),and the Microwave Limb Sounder(MLS)) had been delivered. Modifica-tions to the schedule will accommodatelate April delivery of the TroposphericEmission Spectrometer (TES). Carolyn

Dent summarized results and plans forspacecraft interface testing. The firsttests have included a collection ofsimulated data. Future tests willsimulate normal daily activities(including ground system contacts andTracking and Data Relay Satellite[TDRS] contacts) and contingencyoperations in case of emergency. Glen

Iona provided a brief summary of theMission Planning Review that was heldin February for the Earth Science Dataand Information System (ESDIS)project.

John Gille and John Barnett, HIRDLSco-Principal Investigators, reportedthat an improved retrieval procedurewill take into account the line-of-sighttemperature gradient along the limb.

HIRDLS calibration was completed inDecember 2002. The signal-to-noise inthe instrument exceeds requirements,and it may be possible to include anadditional vertical scan (7 instead of 6)in the across-track direction within 4°of latitude along track. With such lownoise it is possible to complete thescans more rapidly.

Joe Waters (MLS Principal Investiga-tor) reported that MLS noise is alsolower than specifications. The preci-sion estimates provided so far arebased on maximum allowable noise,thus performance on orbit may bebetter than presently advertised.Changes to the MLS instrument,including replacement of a whiskerdiode tripler with a planar diodetripler, will be coordinated withactivities involving TES to minimizeimpact on the spacecraft schedule.

Bert van den Oord representedPieternel Levelt (OMI PrincipalInvestigator). Synthetic OMI data arebeing produced using data from theGlobal Ozone Monitoring Experiment

(GOME) instrument to test the process-ing system. The OMI team recognizesthat the NO2 retrieval relies on the apriori information, and plans to developretrieval methods using constituentassimilation.

Mike Gunson, deputy to Reinhard

Beer (TES Principal Investigator), gavea time history for performance andmodifications of TES during recenttests that revealed problems with thebeam-splitter alignment. TES was incalibration at the time of the scienceteam meeting. TES signal-to-noiseneeds improvement, and options suchas bandpass filtering are being investi-gated.

Reports from Working Groups

The Data System Working Group(DSWG), chaired by Scott Lewicki

,addressed issues that are common toall of the Aura Instrument Teamsincluding data product formats, sciencesystem interfaces and testing, qualityassessment, tools, and end-userinterests. At the last meeting, the team

Figure 1: The Aura Satellite


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expanded on the current HDF-EOSAura File Format Guidelines to specifydata types and field names and laid thegroundwork for comparison of Level 2Aura products, including the use of aDataset Validator tool. They also heardreports from the Earth Science Dataand Information System (ESDIS) onscience-system interfaces, secure datatransfer, and ground-system tests(Mission Operations Science System[MOSS]). Additional topics includedthe development of an EOSDIS CoreSystem (ECS) Metadata editor and theuse of IDL and other tools for examin-ing products in HDF-EOS5.

The Education and Public OutreachWorking Group (Ernest Hilsenrath,chair) reported on recent activities withits partners in getting the word outabout Aura to peers, students and thegeneral public. The American Chemi-cal Society’s ChemMatters magazine,which goes to 30,000 high schoolteachers, has started on its 3rd dedi-cated issue on Aura and atmosphericchemistry. This issue will be releasedin conjunction with “Chemistry Week.”The Smithsonian National Museum ofNatural History is working with NGSTto display a half-scale model of theAura spacecraft as part of the Atmo-spheric Chemistry exhibit to open inSummer 2004.

A Global Learning and Observations toBenefit the Environment (GLOBE)workshop was held to familiarizeteachers with Earth science and howmeasurements tropospheric ozone andaerosols, made by students as part ofGLOBE, could provide results forscience and validation. Visitearthobservatory.nasa.gov for recentarticles on atmospheric chemistry.

The Aerosol Working Group (Steven

Massie, chair) considers issues

concerning aerosols that are commonamong the Aura instruments. The MLScloud-ice retrieval will generate icewater content values greater than 0.005gm/m3 at 100 hPa (report by Dong Wupresented by Steven Massie). IfHIRDLS performs as expected it willretrieve ice water content on the orderof 0.0001 gm/m3. This leaves a datagap for cirrus sizes that will not bemeasured by HIRDLS or MLS. Omar

Torres gave an overview of the TotalOzone Mapping Spectrometer (TOMS)data record and aerosol detectioncapabilities, including detection ofdesert dust over bright reflective desertregions. These same capabilities areexpected for OMI. Data from theTOMS and OMI instruments should becombined to produce a continuousrecord of tropospheric aerosol over thepast 25 years. Alyn Lambert presentedan overview of the development of theHIRDLS aerosol retrieval. The retrievalhas been applied to sulfate aerosolloading for conditions in which theaerosol amount is minimal (currentconditions). Finally, Steve Massie iscontacting those in the volcanologycommunity to find out how the Aurateams can be contacted within hours ofa major volcanic eruption.

B. Bojkov and E. Hilsenrath presenteda proposal for an Aura Correlative DataCenter (ACDC) to the Aura ValidationWorking Group on Tuesday and to theentire Aura Science Team on Wednes-day. The data center’s planned func-tions and implementation werediscussed. Agreement was reached onthe role of the ACDC, the correlativedata format (HDF-4 and HDF-EOS5)that will be implemented, and the set oftools that will be made available to thevalidation teams. A formal proposal forthe ACDC has been submitted to HQfor funding.

Validation

The science team has paid greatattention to the development of thevalidation plan for Aura. The chal-lenge from the Snowmass (1999)meeting to the Aura Science Team isthat validation data beyond routineobservations be obtained within thecontext of science missions.

Mark Schoeberl presented an over-view of Aura validation and itsimplementation plan including thedevelopment of ACDC and a trailerfacility. This overview illustrated thecontributions of data from ground-based networks, other satellites, andspecial observations. These specialobservations include data from ballooninstruments and from aircraft missions.

Lucien Froidevaux presented asummary of the March 18 ValidationWorking Group meeting. This meetingemphasized the routine datasets thatwill be used in Aura validation,including meteorological datasets,sonde data, ground-based data, datafrom airborne instruments that areflown on commercial aircraft, and datafrom other satellites. Plans werepresented (B. Bojkov) for a centrallocation for correlative data as part ofthe ACDC. The correlative datasets,liaisons who assure that the data isavailable, and any issues associatedwith the datasets are summarized intables that can be found at eos-

aura.gsfc.nasa.gov/index.html. Severalairborne missions have been identifiedbetween 2004 and 2006 that areexpected to play an important role inthe validation of Aura data. Theseinclude INTEX/E (midlatitudes,summer 2004), Tropical Compositionand Climate Coupling (TC3)/CirrusRegional Study of Tropical Anvils andCirrus Layers (CRYSTAL — tropics,NH winter 2004/5, NH summer 2005),


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INTEX/W (midlatitudes, spring 2006),and the Polar Auroral Plasma PhysicsSpacecraft (POLAR — high northernlatitudes, winter 2006). The instrumentteams are asked to clarify their needsfor aircraft mission data. This two-partaction item requires the teams tospecify the types of measurements thatwould be most useful (e.g., MLS andHIRDLS both desire along-trackprofiles for 800 – 1000 km), and also toidentify any needs for aircraft data thatare not met by these missions.

Daniel Jacob reported briefly on a fieldexperience during TRACE-P to provideCO profiles for validation of observa-tions by Measurements Of Pollution InThe Troposphere (MOPITT) on Terra.Validation was not a priority for anyflight, but fortunately 50% of theplanned flights provided an opportu-nity for coincidence with Terra over-passes, and flight plans were designedto obtain correlative profiles on two-thirds of these flights. For measure-ments made in clear sky, agreementbetween the in situ profiles andremotely sensed profiles is excellent.Profiles were obtained in the presenceof cirrus, but the MOPITT team has notyet produced retrievals for thiscondition. These in situ profiles willprovide essential information once theretrieval issues have been dealt withsatisfactorily. One problem with theflight-of-opportunity approach tovalidation is that no effort was made toobtain profiles for a range of atmo-spheric conditions. Luck did notprovide a range, and the actualmeasurements vary by only about 10%.This experience underscores the needfor the Aura investigators to specify thetypes of measurements that arerequired for successful validation.

Jim Anderson led a discussion on theUnion of Missions, a document that

develops the conceptual framework forimproved collaboration between theairborne missions with each other andwith spaceborne platforms includingAura. Jim talked about the missingcomponents of the document and theprogress being made. The importanceof developing this conceptual frame-work was underscored during discus-sions of the proposed Tropical Compo-sition, Cloud, and Climate CouplingExperiment (TC4) (see below forsummaries of presentations given byPaul Wennburg and Ross Salawitch).There are multiple questions concern-ing processes in the tropics andsubtropics that will be addressed by thetwo phases of this mission. The flightsthat are proposed will provide uniqueand useful information; however,common sense and analyses show thatthe information that can be obtained byaircraft is limited. The satellite datahave the potential to provide bothcontext for interpretation of aircraftobservations and some quantitativeinformation to understand the pro-cesses on the global scale (see summaryof presentation by Dessler). This on-going dialogue promotes the coordi-nated application of data from satelliteand aircraft to complex sciencequestions.

The A-Train

The scope of scientific applications fordata from Aura and several othersatellites will be broadened by launch-ing Aura and three Earth SystemScience Pathfinder (ESSP) missions —CloudSay, Cloud-Aerosol Lidar andInfrared Pathfinder Satellite Observa-tions (CALIPSO), and the OrbitingCarbon Observatory (OCO) — to fly information with Aqua, in orbit sinceMay 4, 2002. Aura observations ofcloud heights (OMI), aerosols (OMI,HIRDLS), H2O and temperature

profiles (MLS, TES), and cirrus clouds(MLS, HIRDLS) — along with observa-tions from other A-Train participants —will form a much more comprehensivepicture of clouds, aerosols, and watervapor than is possible using observa-tions from any single platform. Thereare many challenges to using this datain concert. For example, the nadirfootprints from the various instrumentsvary drastically. To foster creativethinking and to raise awareness of thecomplementary observations expectedfrom other platforms, one session of theAura science team meeting featuredpresentations about the A-Train and theinstruments that comprise it. Chip

Trepte presented an overview ofCALIPSO, which will provide observa-tions of the vertical distribution andextinction for clouds and aerosols,emissivity of clouds, and single-scattering albedo for aerosols. Charles

Miller described the measurements ofCO2 expected from OCO. Mark

Schoeberl presented an overview ofthe A-Train and reviewed some of themeasurement capabilities of itscomponent missions. These includeinfrared cloud properties, temperature,and water from instruments on Aqua;vertical distribution of clouds byCloudSat; and measurements of aerosoland cloud polarization from a FrenchCentre National d’Etudes Spatiales(CNES) mission called Polariazationand Anisotropy of Reflectances forAtomspheric Science copuled withobservations from a lidar (PARASOL),which will also be part of the forma-tion. It will also be possible to combinedata from multiple missions to producesuch quantities as observation-basedassessments of the radiative effects ofaerosol and clouds that will greatlyimprove our ability to predict futureclimate change.


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Science Presentations

Presentations on topics of interest tothe Aura community were solicited forthis science team meeting and aresummarized below.

Laura Pan presented an overview ofthe National Center for AtmosphericResearch (NCAR) Upper TroposphereLower Stratosphere Initiative. Thisinitiative will bring together a criticalmass of collaborators in a focusedprogram of observations and analysis.Measurements that are part of thisinitiative during 2005 may be useful forvalidation of Aura data; and, oncevalidated, Aura data will play a role inthis initiative.

Paul Wennberg spoke of two closelyrelated campaigns, the TropicalComposition and Climate Coupling(TC3) Experiment and the TropicalWestern Pacific component of CRYS-TAL (CRYSTAL-TWP). Both TC3 andCRYSTAL-TWP emphasize theprocesses that maintain observedhumidity levels in the upper tropo-sphere and lower stratosphere. Thistalk revealed a strategy for a missionTC4 that combines the objective of TC3

and CRYSTAL-TWP and also meetsAura validation requirements.

Ken Jucks provided an overview of theFar-Infrared Spectroscopy of theTroposphere (FIRST) instrument that isbeing developed to fly on a balloonpayload. FIRST spectra can be invertedto yield profiles of upper troposphericand lower stratospheric temperatureand water vapor. Once validated,FIRST measurements can contribute tothe validation measurements fromHIRDLS and MLS on Aura and alsoAIRS, CERES, and MODIS measure-ments on Aqua and Terra.

Mark Kroon presented the OMIvalidation plan for aerosols and NO2,

emphasizing dedicated ground-basedmeasurements. This project willprovide a set of exclusive ground-basedmeasurements, such as the NO2 lidardata for polluted areas in the Nether-lands, Multi-Axis Differential OpticalAbsorption Spectroscopy-Method(MAXDOAS) measurements of NO2 inParamaribo, and aerosol data. This dataset will be used both to validate NO2

and aerosol products and to improvethe retrieval algorithms. It will alsoprovide insight into the relationshipsbetween aerosol properties and NO2 inpolluted regions.

Dorian Abbot presented seven years(1995-2001) of HCHO column data forNorth America from the Global OzoneMonitoring Experiment (GOME), andshowed that the general seasonal andinterannual variability of these data isconsistent with that produced using theGEOS-CHEM 3D tropospheric chemis-try and transport model, and isoprenefrom current emission models. Re-gional discrepancies with the seasonalpatterns predicted from these simula-tions may reflect flaws in the emissionmodels.

Collette Heald presented results fromthe GEOS-CHEM 3-D troposphericchemistry and transport model alongwith satellite observations of carbonmonoxide (CO) from MOPITT andaircraft measurements from theTRACE-P aircraft mission. MOPITTobserved four episodes of trans-Pacifictransport of Asian pollution duringspring 2001 that are simulated by theGEOS-CHEM model. The February 26-27 episode was sampled as a successionof pollution layers at 15-40º N by theTRACE-P aircraft over the northeastPacific. The layers originate from theFebruary 22 event of Asian outflow tothe Pacific along a warm conveyor beltahead of a cold front.

Joan Alexander showed examples ofmomentum flux estimates usingmeasurements made by the CryogenicInfrared Spectrometers and Telescopesfor the Atmosphere (CRISTA). Thetemperature amplitude, verticalwavelength, and horizontal wave-length must be determined simulta-neously to determine momentum fluxand this has been a daunting analysistask for satellite observations. Theseresults are relevant to HIRDLS observ-ing strategies, particularly if theinstrument performs as expected and itis possible to include an additionalscan.

A presentation was given by Ross

Salawitch on the combination of TC3

and CRYSTAL-TWP complemented thetalk given by Paul Wennburg, andemphasized the synergistic science thatwould result from the creation of TC4.The importance of measurements ofisotopes of water vapor (to study theprocesses which dehydrate air enteringthe stratosphere) and measurements ofvery short-lived organic species andtheir products (to determine the budgetof chlorine- and bromine-containingspecies entering the stratosphere) wasstressed.

Pepijn Veefkind showed trends in theaerosol optical thickness calculatedfrom the global dataset derived fromTOMS observations for 1979 to 2001.During this time period the emissionsof aerosol precursors SO2 and NO2 havebeen drastically reduced. Because mostof the aerosols over Europe arecomposed of sulfates and nitrates, it isexpected that the reduction in emissionwill be manifest by a decrease inaerosol optical thickness and accompa-nied by regional warming.

Steve Massie discussed developmentof a cirrus cloud field that can be usedin future tests of the HIRDLS retrieval


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algorithm. The cloud field is basedupon 1994 observations from LITE(Lidar-in-Space Technology Experi-ment, a forerunner of CALIPSO), andextinction was normalized to valuesmeasured by the Halogen OccultationExperiment (HALOE) on the UpperAtmosphere Research Satellite (UARS).These studies clarify the expectedperformance for HIRDLS constituentretrievals in the presence of cirruslayers.

Hiroo Hayashi used observations fromthe Southern Hemispheric ADditionalOZonesondes (SHADOZ) network toinvestigate tropical tropospheric ozonefrom the NASA GSFC ozone assimila-tion system. The shape of the annualmean vertical profile from assimilatedozone, produced using wind fieldsfrom a prototype version of theGoddard Earth Observing System DataAssimilation System (GEOS–4),compares better with observations thanthat produced using winds from aprevious operational system (GEOS-2).

Andrew Dessler showed satellite andin situ evidence that the effects ofconvection on the Upper Troposphere /Lower Stratosphere (UT/LS) weredependent on the relative humidity ofthe UT/LS where the convectionoccurred. If convection injects massinto a region of high humidity, theconvection can dehydrate that region,while convection into regions of lowhumidity hydrates that region. He alsoemphasized the importance of satellitedata for the problem; the pervasiveundersampling of aircraft data makethose data virtually impossible tointerpret on their own.

Laura Pan explored the utility ofconceptual definitions of the extratropi-cal tropopause as a material surface oras a mixing layer using fine scale in situ

measurements of temperature, ozone,

carbon monoxide, and water vapor.These analyses indicate that mixing ofstratospheric and tropospheric airmasses forms a transition layer in thevicinity of the thermal tropopause.The results also indicate that a Pres-sure-Volume (PV) based tropopausedefinition does not work well inlocating the transition layer.

Mark Olsen used Lagrangian trajecto-ries to show that a significant fractionof the air in the tropical upper tropo-sphere/lower stratosphere during thewet/warm phase of the tape recorderoriginates from the extratropical Asianmonsoon. Air reaches tropopauselevels through convection within themonsoon and is transportedequatorward. Data from Aura andAqua instruments should clarify therelative contributions of air that havepassed through the cold tropicaltropopause and moist monsoon air tothe observed tape recorder signal.

Pepijn Veefkind presented differentaspects of a new algorithm to improvethe total ozone product from theGOME instrument by combining theGOME experience with the new insightgained from development of OMIalgorithms. The proposed algorithmincludes an accurate method to deriveand use the cloud fraction and height, atool that recalibrates the GOME Level 1data and the main features of the OMIDifferential Optical AbsorptionSpectroscopy (DOAS) total ozonealgorithm.

Ivanka Stajner showed how the ozonedata assimilation system at NASA’sData Assimilation Office (DAO) ispreparing for Aura with a series ofexperiments investigating the use ofcolumn ozone from either the TotalOzone Mapping Spectrometer (TOMS)or the Solar Backscatter UltraViolet(SBUV) instrument, and vertical ozone

profiles from SBUV. Assimilation ofadditional data, improved forecasterror covariance models, and incorpo-ration of chemistry models each lead toincremental improvements in theassimilated ozone fields.

Krzysztof Wargan demonstrated theimpact of changing the forecast errorcovariance model from a versionassuming static correlations to a flow-following scheme that captures theLagrangian short-term horizontalevolution of those correlations. Theozone fields produced from theassimilation system using the flow-following covariance compares betterwith independent observations withinthe regions where data were notassimilated, particularly at highlatitudes in both hemispheres.

David Lary used an assimilationscheme including a photochemicalmodel constrained by multiplecoincident observations to reconstructfull diurnal cycles from limitedobservations and to check theirchemical self-consistency. This ap-proach propagates sunrise and sunsetinformation obtained through solaroccultation for validation of measure-ments made at other times of day.

Gloria Manney showed process-baseddiagnostics for meteorological fieldsfrom a number of data assimilationsystems, including versions 3 and 4 ofthe Goddard Earth Observing SystemData Assimilation System (GEOS DAS),the European Centre for Medium-Range Weather Forecasting (ECMWF),the MetO (formerly known as UKMO),NCEP, and the NCEP reanalysis.Modeling studies, particularly thoseinvolving transport or temperature-dependent threshold phenomena, canbe highly sensitive to the choice ofmeteorological analysis used.


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A few posters were displayed through-out the meeting. Nathan Winslow

presented a poster detailing improve-ments in the NASA GSFC ozoneassimilation product relative to ozonesondes when MLS profiles are assimi-lated along with TOMS columns andSBUV profiles. A poster by Alexander

Sinyuk presented a method forretrieval of the imaginary part of therefractive index of desert dust aerosolat near-UV wavelengths. Omar Torres

showed comparisons of the aerosol

A silver swath of sunglint surrounds half of the Hawaiian islands in this true-color Terra MODIS image acquired on May 27, 2003. Sunglint revealsturbulence in the surface waters of the Pacific Ocean. If the surface of the water were as smooth as a mirror, we would see the circle of the Sun as a perfectreflection. But because the surface of the water is ruffled with waves, each wave acts like a mirror and the Sun’s reflection gets softened into a broader silverswath, called the sunglint region. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

optical depth and single-scatteringalbedo derived from near-UV observa-tions by the Earth Probe Total OzoneMapping Spectrometer with observa-tions made at AERONET stations inAfrica and in the United States. TOMSand AERONET single-scattering albedoagree within 0.03. Mark Schoeberl

used diabatic heating rates to calculatethe flux of mass from the stratosphereto the troposphere, and attributed themass change in the lowermost strato-sphere to diabatic and adiabatic

processes. Results were found to differdepending on the source of meteoro-logical fields used in the analysis. Healso found that there was a net adia-batic flux of mass into the middleworld.

The next Aura Science Team meetingwill be held in Pasadena, CA, the weekof September 30, 2003. This meetingwill include a field trip to visit the Auraspacecraft before its January 2004launch.


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The 28th Clouds and the Earth’sRadiant Energy System (CERES)Science Team meeting was held inNorfolk, VA, on May 6-8, 2003. Themeeting focused on the new MonthlyTop-of-Atmosphere/Surface Averages(SRBAVG) products, early results fromTerra Angular Distribution Model(ADM) development, cloud accuracyresults from Terra, Terra Edition2instrument and ERBE-like (ERBE is theEarth Radiation Budget Experiment)results with calibration refinement,Aqua Instrument and ERBE-likeproduct status, and performance ofTerra surface fluxes. The next CERESScience Team Meeting is planned forSeptember 23-25, 2003 in, Hampton,VA.

CERES on NPOESS and NPP

Bruce Wielicki (Langley ResearchCenter [LaRC]) noted that a clearpicture of CERES on the National PolarOrbiting Environmental SatelliteSystem (NPOESS) is not expected toemerge until next year. The EarthScience Enterprise has directed thatprovisions be made to accommodate aCERES instrument on the NPOESSPreparatory Project (NPP) spacecraft tofill the anticipated gap in the radiationbudget data record between Aqua andNPOESS. This leaves the door open tofly CERES on NPP, but a final decisionhas not been made. Aqua and Terrawill not be de-orbited; the latestestimate of risk of a gap in broadbandradiation budget data without CERESon NPP is 16 to 42% through 2012,depending on Geostationary Earth

Radiation Budget (GERB) success,launch dates, and mission lifetimes.CERES on NPP reduces the gap risk to6%.

CERES Instruments on Terra and

Aqua

Kory Priestley (LaRC) gave theinstrument calibration/validationreport. The Terra Deep Space Calibra-tion sequence executed flawlessly andscience data analysis is continuing.Initial results indicate minimal changesfrom pre-launch measurements of scanangle dependent offsets. Terra Edition2bi-directional scan (BDS) and ERBE-likeproducts are available through Decem-ber 2002. A factor of five improvementhas been achieved in stability and biasfor shortwave (SW) and daytimelongwave (LW) Edition2 products.Terra has unprecedented stability levelsof ~0.1%/yr for the CERES climaterecord. Aqua Edition1 BDS productsare now available. Intercalibrationsbetween Terra and Aqua allow theinstruments to be placed on the sameradiometric scale: The SW and LW/night agreement is within 0.4%; LW/day agreement is better than 0.7%; andwindow channel (WN) agreement iswithin 1.0%.

Terra Edition2 ERBE-Like Flux

Takmeng Wong (LaRC) examined thetime series of CERES/Terra Edition2tropical-mean and global-mean top-of-atmosphere (TOA) radiation budgetsand found no statistically significanttrends during the first 34 months ofdata. His analyses also revealed thatregional radiative effects of the 2002 El

Niño event are large, up to 80 W/m-2.A comparison of ERBE-like andSRBAVG results for March 2000showed a large clear-sky bias awayfrom the Tropics, small LW differencesin most zones, and a large latitudinaldependence in all-sky SW and net fluxbiases.

TRMM and Terra Time-Averaged

Products

David Young (LaRC) reported that theTerra gridded geostationary (GGEO)products are now being run for the firstyear of data. Improvements related tosurface emissivity, sun angle, and time-dependent calibrations were incorpo-rated. Other enhancements involvinggeostationary satellite navigation,surface albedo, and bringing in newsatellites are in progress. Validation iscontinuing for the archived TropicalRainfall Measuring Mission (TRMM)SRBAVG product. A beta version of theTerra SRBAVG marks the first of a newgeneration of global monthly meanproducts. The Terra beta MonthlyGridded TOA/Surface Fluxes andClouds (SFC) product is in the archive,and the Aqua beta SFC product hasbeen delivered.

TRMM/Terra Clouds and Radiative

Swath (CRS) Results

Tom Charlock (LaRC) reported thatTRMM CRS Edition2C was produced,but still neglects organic carbonaerosols and has a few other knownerrors. The LaRC Fu-Liou radiativetransfer code is being modified to: 1)

CERES Science Team Meeting

— Gary G. Gibson, [email protected], NASA Langley Research Center— Shashi K. Gupta, [email protected], NASA Langley Research Center


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produce multiple-sky conditionoutputs including clear-sky with andwithout aerosol, and all-sky with andwithout aerosol for multiple-cloudconditions; and 2) include a newinhomogeneous cloud optical depthsolver. Code structural modificationshave been introduced which reduceexecution time for Surface and Atmo-sphere Radiation Budget (SARB) byabout 40%.

Angular Distribution Models

Norman Loeb (Hampton University)presented results of TOA radiative-fluxestimation from CERES ADMs. Earlyresults from Terra ADMs showimprovement over those from TRMM,especially outside the Tropics. FinalTerra ADMs based on 2 years ofCERES/Terra rotating azimuth plane(RAP) measurements will be completedin September 2003. More work isneeded to evaluate the quality of 1°-resolution SW clear land ADMs and fitsfor ocean LW ADMs. SW and LWADMs are not yet developed for cloudsover land and desert. Part I of a journalpaper describing CERES/TRMM SW,LW, and WN ADMs was published,and Part II summarizing TRMM ADMvalidation results was accepted.Another paper on the use of neuralnetworks for TOA flux estimation wasalso accepted.

Cloud Algorithms and Results

Patrick Minnis (LaRC) summarizedcloud system results and validation forTerra, and algorithm improvementsand initial results for Aqua, andrequired algorithm enhancements forhandling multi-layer clouds, polarclouds, and partly-cloudy pixels.TRMM Visible-InfraRed Scanner (VIRS)Edition2 processing is complete, TerraEdition1a has been run for February

2000 to January 2002, and Aqua Beta1 isnow available for September andOctober 2002. Overall, validationresults are encouraging and a roadmapfor improving known deficiencies is inplace.

Data Management

Mike Little (LaRC) reported on thestatus of science data products,processing environment, and technol-ogy advances. TRMM data processingis complete until the next majorreprocessing. Terra Edition2 is com-plete through the end of 2002. Acombined Terra/Aqua Edition1product is planned. Several hardwarechanges are underway to improve theenvironment for development andtesting of science codes and providecomputing capacity for unscheduledrequirements. In the longer term,software may be converted to operatein an open source (LINUX) environ-ment to improve efficiency. James

Koziana (SAIC) briefed the team onordering data from the AtmosphericSciences Data Center (ASDC) and onsubsetting CERES data products.Michelle Ferebee (LaRC) reported onthe status of the ERBE Digital Librarybeing developed at the ASDC.

Educational Outreach

Lin Chambers (LaRC) reported that theCERES Students’ Cloud ObservationsOn-Line (S’COOL) project now has1450 participating schools in 62countries. The 5th annual S’COOLteacher workshop will be held in June.The latest S’COOL newsletter wasdistributed in March in English,French, and Spanish.

Invited Presentations

Grant Matthews (Imperial College,London) presented the status of theGERB instrument which was launchedin August 2002 aboard the MeteosatSecond Generation (MSG) satellite.The GERB experiment is a cooperativeproject between U.K., Belgian, andItalian scientific institutions and wasbuilt and calibrated in the U.K. It is thefirst instrument to measure thebroadband SW and LW radiationbudget from a geostationary platform.GERB produces a radiation budgetmap every 15 minutes at a spatialresolution of 40 km x 40 km which willbe enhanced to 10 km x 10 km usingdata from Spin Enhanced VisibleInfraRed Imager (SEVIRI), a highspatial resolution imaging instrumentalso flying aboard the MSG. GERBprocessing is using many of the datareduction procedures developed forCERES. Design lifetime of a GERBinstrument is 3-5 years.

Takmeng Wong (LaRC) and Zachary

Eitzen (Colorado State University)presented results from a study of cloudsystems motivated by the desire tobetter understand cloud-radiativefeedbacks in the climate system andreduce uncertainties in the simulationof cloud-radiation interactions in theglobal climate models (GCMs). Thisstudy involved analysis of the subgrid-scale characteristics of clouds obtainedfrom the CERES cloud processingsystem and comparing them withresults of simulations from modelsdriven by meteorological input datafrom the European Centre for Medium-Range Weather Forecasts (ECMWF).CERES/TRMM cloud retrievals forMarch 1998 (strong El Niño) and March2000 (weak La Niña) were analyzed.Probability density functions and otherstatistics were derived for TOA SWflux, outgoing LW, TOA albedo, cloud


11

optical depth, liquid water path (LWP),ice water path (IWP), and other cloudparameters. Cloud-height distributionsfor tropical deep convective systemswere found to be very different for ElNiño and La Niña conditions. Cloudtop height and LW distributions werefound to be insensitive to sea surfacetemperature changes above 301 K.

Xiquan Dong (University of NorthDakota) presented validation of cloudproperties derived by the LaRC cloudgroup from Terra Moderate ResolutionImaging Spectroradiometer (MODIS)data against ground-based measure-ments from the Atmospheric RadiationMeasurement (ARM) Southern GreatPlains (SGP) and North Slope of Alaska(NSA) sites. Comparisons at the SGPsite were presented for the period fromNovember 2000 to December 2001.Two methods were used for averagingsatellite retrievals. For the firstmethod, data were averaged over a 30-km x 30-km area centered on the site.For the second method, data wereaveraged along a 3-km wide wind stripover one hour centered on the time ofsatellite overpass. Wind speed anddirection were obtained from theECMWF data. Dong found that thewind strip method was more successfulat detecting clouds. Cloud heightsshowed good agreement for solidcirrus and mid-level clouds. Forstratus clouds, wind strip averagevalues of particle size agreed well withsurface data, but optical depth andLWP values were much lower.

Investigator Presentation Highlights

David Kratz (LaRC) presented valida-tion of Terra Single Scanner Footprint(SSF) surface-only SW and LW fluxesderived using TOA-to-surface transferalgorithms and fast radiationparameterizations. Validation wasdone on an instantaneous/footprint

basis using surface-measured fluxesfrom a number of different climateregimes. Kratz concluded that clear-sky and all-sky LW fluxes meet thestated accuracy goal of ±20 Wm-2

considered desirable for climateresearch applications. Clear-sky SWfluxes showed good agreement, but all-sky fluxes showed a large scattercaused by cloud spatial variability.Efforts are underway to improve theall-sky SW comparisons.

Gerald (Jay) Mace (University of Utah)presented results from a case study ofthe evolution of a cirrus anvil based onsatellite, aircraft, and surface-basedobservations on July 16, 2002, duringthe Cirrus Regional Study of TropicalAnvils and Cirrus Layers - Florida AreaCirrus Experiment (CRYSTAL-FACE).Geostationary Operational Environ-mental Satellite (GOES) data providedthe temporal context while aircraft andsurface data provided vertical crosssections. Mace concluded that com-bined observations like these should beused to derive cloud properties and toexamine the statistics of the empiricalrelationships for different cloud typesand events.

James Coakley (Oregon State Univer-sity) presented results of a new methodfor retrieving cloud properties frompartially cloud-filled pixels. He statedthat partially cloud-filled pixels occureven at the highest spatial resolution(including 1-km MODIS data). Cloudproperties derived from these pixelswith a clear/overcast threshold methodare subject to significant errors. Thepartially cloudy method is based onadjusting the cloud amount, opticaldepth, and droplet radius to ensure amatch between computed and ob-served radiances at 0.64, 3.7, and 11 µm.Coakley’s results for several scenes ofVIRS 2-km data and MODIS 1-km data

showed that a threshold methodgenerally overestimated the cloudcover, underestimated the opticaldepth, and overestimated the dropletradius.

Bing Lin (LaRC) presented results froma study of liquid/ice water paths andthe vertical structure of clouds asobserved from instruments aboard theTRMM satellite by comparing cloudproperties retrieved from VIRS andTRMM Microwave Imager (TMI) data.VIRS-based retrievals came fromCERES processing; Lin’s microwaveradiative transfer model was used toanalyze the TMI data. For comparison,VIRS cloud products were convolutedto match the larger TMI fields-of-view.CERES/VIRS and TMI LWP retrievalsfor warm clouds were found to be invery good agreement. VIRS overesti-mation of IWP for high clouds wasattributed to the presence of low cloudsunderneath the cirrus layers.

Robert Cess (State University of NewYork, Stony Brook) analyzed the impactof clouds on the radiation budgets of 19atmospheric GCMs. He expressedconcern that a dozen years ago theestimated temperature response to CO2

doubling among the models varied bya factor of 3, and the situation has notchanged much since then. He com-pared the effects of clouds in 19 GCMsagainst results from multi-year 3-month averages of SW, LW, and netcloud radiative forcing (CRF) fromERBE observations. For zonal aver-ages, most models underestimated SWCRF while LW CRF compared better.Averages of net CRF over a 60N-60Sdomain agreed well for some modelsbut not for others. Comparisons of netCRF over the Pacific Ocean showedthat some models compared better overthe eastern region while others didbetter over the western region. Com-


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parisons of clear-sky reflected SW fluxand outgoing LW showed disturbinglylarge differences between the modelsand relative to ERBE values.

Anand Inamdar (Scripps Institution ofOceanography) presented a study ofthe atmospheric LW cooling overtropical oceans inferred from CERES/TRMM data. He analyzed TRMM/SSFdata to demonstrate the magnitudes ofLW cooling separately for the WN andnon-window regions. Specifically,imager-based surface skin temperature,microwave precipitable water vaporover oceans, outgoing LW, outgoingWN flux, and downward broadbandand WN fluxes were analyzed.Corresponding non-window quantitieswere computed from the broadbandand WN values. Inamdar presentedplots of WN and non-window surfaceand atmospheric cooling effects asfunctions of sea surface temperatureand column precipitable water vapor.

Shi-Keng Yang (NOAA NationalCenters for Environmental Prediction,NCEP) presented an analysis of thetrends in tropospheric humidity in theNCEP/National Center for Atmo-spheric Research (NCAR) reanalysisduring the pre-satellite period (1949-1978). He showed that TOA LW CRF inthe reanalysis continually decreasedduring this period and was related tothe decrease in 500 hPa relativehumidity. Yang also analyzed TOA andsurface radiative fluxes from the latestAtmospheric Model IntercomparisonProject (AMIP) simulations at NCEP,that used the current global forecastmodel. He concluded that the currentNCEP global forecast model was notable to simulate the ERBE and CERESobservations well. Like many otherGCMs, it did not reproduce the decadalvariability of TOA radiation shown byWielicki et al. from satellite observa-

tions.

Ron Welch (University of Alabama inHuntsville/UAH) presented compari-sons of CERES- and MODIS-derivedcloud masks over the ARM/NSA sitewith various ground-based measure-ments. Large differences were foundbetween CERES mask and surfaceestimates, particularly for high, thinclouds. The MODIS algorithm gener-ally detected more high, thin cloudsthan the CERES algorithm but some-times found clouds where surface dataindicated clear skies.

Qingyuan Han (UAH) identified twoimportant sources of uncertainty in theretrieval of ice cloud properties. Thefirst is the use of empirical particle sizedistributions. He suggested that theuse of theoretical size distributionsgreatly reduces the large uncertaintiesin single scattering properties. Thesecond source of uncertainty was theuse of a single crystal habit (shape) bymany retrieval algorithms. Forexample, the CERES algorithmassumes ice particles to be hexagonalcolumns, ISCCP algorithm assumesthem to be polycrystal, and MODISalgorithm assumes a combination ofthree shapes. These assumptions leadto large uncertainties in effectiveparticle size, single scattering proper-ties, as well as cloud emissivity andalbedo. Han suggested that morerealistic habits could be derived usingCERES RAP observations.

Michel Viollier (Laboratoire deMeteorologie Dynamique, France)compared CERES/Terra and earlyGERB measurements with broadbandfluxes derived from POLarization andDirectionality of Earth’s Reflectances(POLDER) data by using narrowband-to-broadband conversion algorithms.POLDER-2 began providing data in

early February 2003 and became fullyoperational in April. Viollier alsodiscussed the status of Megha-Tropiques, a cooperative Indo-Frenchmission which will carry two passivemicrowave instruments and a radiationbudget instrument in a low-inclinationorbit for studying tropical water andenergy cycles.

Nicolas Clerbaux (Royal Meteorologi-cal Institute of Belgium, RMIB)reported on the status of activities atthe RMIB where high spatial andtemporal resolution TOA radiativefluxes will be produced using observa-tions from a geostationary platform.This will be accomplished with acoordinated use of data acquired by theGERB and SEVIRI instruments aboardthe MSG satellite. A resolutionenhancement technique will be used toconnect the broadband GERB fluxretrievals to 10 km x 10 km blocks ofSEVIRI pixels.

Thomas Charlock (LaRC) presented anassessment of the direct aerosol forcing(DAF) of TOA, surface, and atmo-spheric radiative fluxes for clear- andall-sky conditions. Clear-sky resultswere presented for a month (April1998) and all-sky results for a day (June17, 1998). He found good agreementfor April 1998 between DAF values atthe TOA for tuned clear-sky fluxes andfor CERES observations. Charlockused Global Aerosol ClimatologyProject data to show the distribution ofaerosol optical thickness (AOT)differences between April 1998 andApril 1989 to contrast an El Niño year(1998) with a non-El Niño the SouthernHemisphere (SH) and lower AOT in theNorthern Hemisphere (NH) duringApril 1998, and suggested that the ElNiño may be causing a decrease(increase) of AOT over the NH (SH)oceans. Also, since most of the aerosol


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heating of the atmosphere occurs in theNH, the April 1998 El Niño may besuppressing that atmospheric heating.

Alexander Ignatov (NOAA NationalEnvironmental Satellite, Data, andInformation Service, NESDIS) com-pared aerosol optical propertiesretrieved over the oceans as a part ofCERES processing with correspondingMODIS retrievals. CERES retrievalswere made with single channel (like theAdvanced Very High Resolution

Radiometer, AVHRR) algorithms whileMODIS retrievals were made with amulti-channel algorithm. Severalcomparisons of both Terra and Aquaretrievals for AOT at 0.659 and 1.64 µm,and the Angstrom exponent, Å, wereshown. The two products showedgood agreement.

T. Zhao (NOAA/NESDIS) examinedthe differences of AOT and Å, retrievedwith AVHRR-like and MODIS algo-rithms, and also compared them with

Aerosol Robotic Network (AERONET)observations for March 2001. He foundthat the differences of AOT at bothwavelengths (0.659 and 1.64 µm) werecaused primarily by cloud contamina-tion of the clear footprints used inretrievals. Reducing the effects ofcloud contamination on the retrievalsbrought the results of the two algo-rithms close to each other and to theAERONET observations.

CERES measured the thermal energy or heat emitted from the United States, as shown in this image from May 2001. The record-setting high temperaturesexperienced in Southern California and Nevada on May 9 are visible in the light areas where great amounts of thermal energy are escaping to space. Thisexample illustrates one of the most basic stabilizing forces in the Earth's climate system: clear hot regions lose more energy to space than cold areas. Theregions of low thermal emission over the northern U.S. are cold cloud tops. CERES data will be used to verify the ability of climate models to accuratelypredict this emission as our world experiences changes in surface reflectivity, clouds, atmospheric temperatures, and key greenhouse gases such as watervapor.


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Summary of the Joint CloudSat/CALIPSO Science TeamMeeting— Debra Krumm, [email protected], Colorado State University— Kim Cannon, [email protected], NASA Langley Research Center— Deobrah Vane, [email protected], Jet Propulsion Laboratory— Pat McCormick, [email protected], Hampton University, something

A joint CloudSat/Cloud Aerosol Lidarand Infrared Pathfinder SatelliteObservations (CALIPSO) Science Teammeeting was held March 3-6, 2003, inBroomfield, CO, and was chaired bythe respective Principal Investigators(PIs), Graeme Stephens (Colorado StateUniversity) and Dave Winker (NASA-Langley Research Center). TheCALIPSO and CloudSat satellites areco-manifested on a Delta II, scheduledfor launch in November 2004. Many ofthe science team members belong toboth missions, and much of the sciencereturn and many of the scientificoperations are of interest to bothgroups. The meeting was well attendedand participant feedback indicates themeeting was very successful. Anotherjoint Science Team meeting will beplanned as the missions near launch.

Afternoon Constellation (‘A-Train’)

CALIPSO and CloudSat are NASAEarth System Science Pathfinder (ESSP)missions and will become part of theAfternoon Constellation (knowninformally as the “A-Train” after thefamous jazz tune “Take the A-Train,”by Billy Strayhorn—See NASA Facts,FS-2003-1-053-GSFC for additionalinformation). The other satellites in thepolar-orbiting constellation are Aqua,Aura, and Polarization and Anisotropyof Reflectances for Atmospheric ScienceCoupled with Observations from aLidar (PARASOL), a French CentreNational d’Etudes Spatiales (CNES)

mission. The five satellites mentionedabove will eventually be joined by asixth, the ESSP-sponsored OrbitingCarbon Observatory (OCO).

CloudSat Mission

CloudSat will carry a special type ofhigh frequency radar (94 GHz). Thiscloud-profiling radar (CPR) willprovide the vertical distribution ofcloud physical properties includingliquid water content, ice content, andcloud optical depth [Stephens et al.,2002]. The CloudSat mission is acooperative effort that includes itsinternational partner, Canada, and itsindustry partner, Ball Aerospace andTechnologies Corporation. AmongCloudSat’s other partners are Colorado

State University (CSU), Jet PropulsionLaboratory (JPL), Canadian SpaceAgency, the U.S. Air Force, U.S.Department of Energy, Goddard SpaceFlight Center and scientists fromFrance, United Kingdom, Germany,Japan and Canada. For additionalinformation, the CloudSat website is:cloudsat.atmos.colostate.edu/.

CALIPSO Mission

CALIPSO will carry a two-wavelength,polarization lidar and two passiveinstruments to provide an opportunityfor more comprehensive atmosphericdata collection on aerosols and opti-cally thin cirrus. Lidar is similar toradar but sends pulses of light gener-ated by a laser through the atmosphere,

Figure 1: The Cloud Aerosol Lidar and Infrared Pathfinder Sallite Observations (CALIPSO) Satellite


15

Figure 2: The A-Train satellite constellation.

where a fraction is then scattered byaerosols and cloud particles back to theinstrument . The CALIPSO satellite willprovide vertical profiles of aerosols andclouds using the first satellite lidardedicated to atmospheric sensing[Winker et al., 2003]. The lidar willobserve the vertical distribution ofaerosols and clouds and the passiveinstruments will provide additionalinformation on particle properties,improving our understanding of therole aerosols play in Earth’s climatesystem. The CALIPSO mission is acooperative effort led by NASA’sLangley Research Center (LaRC) andincludes the French space agencyCNES, Hampton University, BallAerospace and Technologies Corpora-tion (Ball), and the French InstitutPierre Simon Laplace. For additionalinformation, the CALIPSO website is:www-calipso.larc.nasa.gov.

Joint CloudSat/CALIPSO Science

Team Meeting

Monday, March 3

The first day of the meeting was afocused CALIPSO Science Teamsession, which included presentationson recent characterization test resultsfor the lidar detector and the status ofLevel 2 lidar algorithms. This sessionwas adjourned for a tour of CALIPSOand CloudSat hardware at the nearbyBall facility in Boulder. The meetingreconvened that evening with a jointCloudSat/CALIPSO town hall sessionto discuss strategy for a NASA Re-search Announcement (NRA) as well asconcepts for the next mission. TheMission PIs, Graeme Stephens (CSU)and Dave Winker (LaRC), and EarthScience Enterprise (ESE) ProgramManager for Radiation Science, DonAnderson (NASA Headquarters—CodeYS) led the discussion.

Tuesday, March 4

Tuesday morning kicked off three daysof joint CloudSat/CALIPSO sessionswith a welcome from the Mission PIsand opening remarks from DonAnderson. Tuesday’s joint sessionincluded project status reports byCALIPSO and CloudSat projectmanagement. John Rogers (LaRC), theCALIPSO Project Manager, highlightedthe recently approved project replan.Mark LaPole (Ball), the CALIPSOPayload Manager presented the statusof the payload, highlighting progress ineach of the payload components. TomLivermore (JPL), the CloudSat ProjectManager, gave an overview of projectstatus and Randy Coffey (Ball), theCloudSat Spacecraft Manager, pre-sented an overview of the spacecraft,highlighting recent progress in devel-opment. John Stadler (LaRC), theCALIPSO Systems Engineer, discussedchanges to the on-orbit formation tominimize impacts of sun glint on theoverall science objectives. The rest ofthe morning and afternoon werededicated to updates of the sciencealgorithms and descriptions of dataproducts (Joint Session III). A receptionheld Tuesday night at the Omni wasthe site of the now infamous CloudSatCup Competition. Because of thenumber of injuries during previous

competitions, checkers was chosen asthe ‘sport event.’ Traditionally, theCloudSat Cup pits the engineersagainst the scientists and traditionally,the scientists led by Graeme Stephenshave won. Congratulations to theengineers, led by Tom Livermore, whoemerged victorious for the first time infour years—unfortunately the covetedCloudSat cup disappeared during theevening.

Wednesday, March 5

Wednesday morning, Joint Session IV,addressed the progress in globalclimate modeling and data assimilationand took advantage of the localexpertise at NCAR and CSU, as well asthe international mission participationfrom CloudSat and CALIPSO. Thistheme continued during the afternoonin Joint Session V that consisted ofspecial reports on other missions.Didier Tanre (Laboratoire d’OptiqueAtmospherique/Centre National de laRecherche Scientifique), PI on PARA-SOL, brought everyone up to date onPARASOL and its instrument, Polariza-tion and Directionality of EarthReflectances (POLDER 2). PedroBaptista (ESA/ESTEC) discussedEarthCare simulation, and FranciscoValero (Scripps Institution of Oceanog-raphy/UCSD) gave an overview of


16

Figure 3: The CloudSat Satellite

Deep Space Climate Observatory(DSCOVR—formerly Triana).Validation is a topic of extremeimportance to any mission, and theValidation Activities session was thefocus for the remainder of this meeting.Among the current and future cam-paigns and field experiments that werediscussed and offer potential benefit toCloudSat and CALIPSO were theCirrus Regional Study of TropicalAnvils and Cirrus Layers Florida AreaCirrus Experiment (CRYSTAL-FACE),the Tropical Western Pacific Campaign,the Atmospheric Radiation Measure-ment Program (ARM), MIRAI, Re-gional East Atmospheric Lidar Mesonet(REALM), and others. The validationactivities of other satellite missionsincluding Aura (another A-Trainmember) and Terra were also pre-sented.

Thursday, March 6

The final day of the meeting beganwith CALIPSO taking credit for theCloudSat “cupnapping.” A ransomnote was delivered shortly after themeeting and it is believed that theCloudSat Cup is currently on a world-wide tour until those demands are met.The morning presentations began witha break from validation. The CALIPSOCo-PI, Pat McCormick (HamptonUniversity), teamed with DebraKrumm (CSU), director of educationand public outreach for CloudSat, todescribe the cooperative plans that thetwo missions have for reaching out tothe public and to students around theworld in Joint Session VII. Studentswill be organized to collect data toprovide ground-based observationsthrough the NASA-sponsored Global

Learning and Observations to Benefitthe Environment (GLOBE) program.

The final day returned to the validationtheme with several more presentations,and the meeting concluded with asession on one of the groundbreakingaspects of these two missions, combin-ing multi-sensor data (Joint SessionVIII). Combining sensors achievessynergy, meaning more informationabout the Earth will be obtained fromthe combined observations of thedifferent satellites and their instru-ments as a formation, than would bepossible from the sum of the observa-tions taken independently. Achievingsynergy between the missions will alsobe one of the most difficult engineeringaspects of the two missions and theremaining presentations highlightedthe promise and potential of thesesynergistic observations.

References

Stephens, Graeme L., Deborah G. Vane,Ronald J. Boain, Gerald G. Mace,Kenneth Sassen, Zhien Wang, AnthonyJ. Illingworth, Ewan J. O’Connor,William B. Rossow, Stephen L. Durden,Steven B. Miller, Richard T. Austin,Angela Benedetti, Cristian Mitrescu,and the CloudSat Science Team. 2002.The CloudSat Mission and the A-Train: A

New Dimension of Space-Based Observa-

tions of Clouds and Precipitation. Bulletin

of the American Meteorological

Society, vol. 83, number 12, pp. 1771-1790. December.

Winker, David M., Jacques Pelon, and

M. Patrick McCormick, 2003: The

CALIPSO mission: Spaceborne lidar for

observation of aerosols and clouds. Proc.

SPIE, vol 4893, pp. 1-11.


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The Advanced Spaceborne ThermalEmission and Reflection Radiometer(ASTER) Users Workshop was heldApril 28-29, 2003, in Arcadia, Californianear the Jet Propulsion Laboratory(JPL). Over 100 participants attendedthe two-day workshop dedicated toteaching users about ASTER data. Thefirst day of the workshop was devotedto descriptions of the instrument,calibration, data products, and dataordering tools. The second day wasdevoted to presentations of scientificapplications. Speakers came from theU.S. ASTER Science Team, the LandProcesses Distributed Active ArchiveCenter (LPDAAC), the JapaneseGround Data System, and the Univer-sity of California Davis. Throughoutthe two days, participants had access tointernet-enabled workstations. With theassistance of LPDAAC staff, they wereable to learn how to search and orderASTER data through the U.S. and Japandata systems, explore the data throughthe Global Visualization (GLOVIS) tool,and order U.S. data through the DataPool tool.

Michael Abrams, JPL, AssociateASTER Science Team Leader, wel-comed the participants and presentedthe agenda for the two-day workshop.Anne Kahle, JPL, ASTER Science TeamLeader, presented an overview of theASTER instrument, the history of theASTER project, and described thecollaboration between the U.S. andJapan.

Radiometric calibration was covered byStuart Biggar and Kurt Thome

(University of Arizona) and Simon

Hook (JPL). They described howcalibration and validation of the ASTERinstruments is done through analysis ofon-board calibration lamps and theirresponse; and through regular, inten-sive field validation campaigns. Fieldwork involves selecting large, homoge-neous ground targets, such as drylakes, sand dunes, and lakes. The sitesare occupied during instrumentoverpasses, and thoroughly instru-mented to measure surface radiativecharacteristics, solar radiance, meteoro-logical conditions, etc. The measuredsurface parameters are convolved withmodels, and the values are compared tothe instrument -measured values.

The next presentation was by Michael

Abrams, covering the ASTER dataproducts. ASTER provides 14 standarddata products; some are geophysical,derived products, such as reflectance atthe surface. Each product is periodi-cally validated to verify performance ofthe algorithms, and to look for instru-ment anomalies.

The remainder of the afternoon wasdevoted to descriptions of dataordering and browsing tools availableonline. Hiroshi Watanabe discussedthe Japanese Ground Data System andthe browse and order capabilitiesoffered through web sites. In addition,he described the scheduling and dataprocessing done in Japan. Bryan Bailey,Bhaskar Rhamachandran, and Zheng

Zhang from the Land Processes DAACdescribed the EOS Data Gateway webtool used in the U.S. to access all EOS

data. They also described two ASTER-specific tools: the Global VisualizationViewer (GLOVIS), a tool for browsingimages; and Data Pool, a tool todownload data only over the US.

Larry Rowan (US Geological Survey[USGS]) opened the second day ofapplications discussions, and talkedabout using ASTER data for mineralmapping. He showed how to useshortwave infrared data with visibleand thermal data to extract mineralspectral signatures, and described thelimitations of the ASTER discretebands. Tom Schmugge, U.S. Depart-ment of Agriculture, described hisresearch into extracting surface energy-balance parameters by combiningASTER data, field measurements, andanalytical models. Simon Hook, JPL,talked about lake studies using ASTERthermal data. His study site at LakeTahoe illustrated using the data fortemperature monitoring, and lakecirculation studies. Alan Gillespie,University of Washington, presentedseveral environmental applications,including determining ages of clearcuts and forest regrowth, climatologicalstudies in Tibet, and stream-tempera-ture determinations. Susan Ustin,(University of California, Davis),described vegetation studies, focusingon agricultural crop monitoring andclassification using ASTER data in theCalifornia Central Valley. Jeff Kargel,(USGS), presented a talk on the GlobalLand Ice Measurements from Space

ASTER Users Workshop— Mike Abrams, [email protected], Jet Propulsion Laboratory


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This image of Mt. Usu volcano is dominated by Lake Doya, an ancient volcanic caldera. On the south shore is the active Usu volcano. Friday, March 31,2000, more than 11,000 people were evacuated by helicopter, truck, and boat from the foot of Usu. The volcano began erupting from the northwest flank,shooting debris and plumes of smoke streaked with blue lightning as high as 2,700 meters (8,850 feet) into the air. Although no lava flowed from themountain, rocks and ash continued fo fall after the eruption. This was the seventh major eruption of Mount Usu in the past 300 years. Fifty people died whenthe volcano erupted in 1822, its worst known eruption.

(GLIMS) project, that is using ASTERdata to monitor thousands of glaciersworldwide. The project is a collabora-tion between 24 international organiza-tions. Dave Pieri (JPL) spoke onvolcano monitoring using ASTER.Several unique capabilities werehighlighted, including mapping SO2

emissions, determining lava-domephysical characteristics, and hot-spotmapping. Mike Ramsey (University ofPittsburgh) described the Urban

Environmental Monitoring project heleads. The goal of the project is tocharacterize and monitor 100 citiesaround the world using a variety ofdata types.

The workshop presentations areavailable on CD. Please send yourrequest to [email protected]


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EOSDIS manages data from NASA’spast and current Earth science researchsatellites and field measurementprograms, providing data archiving,distribution, and information manage-ment services. Over two terabytes ofdata are being produced by the EOSproject each day. The transmission andarchiving of such an unprecedentedamount of data requires tremendousprocessing time, computer storage, andI/O bandwidth. One technique that canreduce data storage and networkrequirements without compromisingdata fidelity is lossless data compres-sion.

The most commonly used lossless datacompression techniques are based onthe Lempel-Ziv-77 (LZ77) algorithm(e.g., gzip or its variations). Thistechnique, however, generally yieldspoor compression ratios on dataoriginating from spacecraft instru-ments. A second well-establishedtechnique is arithmetic coding (e.g.,JPEG arithmetic coding). This tech-nique works on most types of data, butexhibits relatively slow speed due tothe need to update statistics during theprocess. The Consultative Committeeon Space DataSystems(CCSDS) hasadopted theextended-Ricealgorithm as therecommended

compression standard for internationalspace applications. This technique wasdeveloped specifically for scienceinstrument data through a joint effortbetween NASA GSFC and the JetPropulsion Laboratory (JPL), based onrequirements for high speed real timeprocessing, low complexity, and quickadaptation to statistics. It has beenimplemented for many space missionsin both instruments and data systemsand base-lined for many futuresatellites as well.

In 1998, the Earch Science TechnologyOffice (ESTO) / Earth Science Data andInformation System (ESDIS) supporteda prototype study to evaluate theperformance of these different datacompression techniques applied to EOSdata. The performance of differentlossless data compression techniqueswas compared on typical EOSDISHDF-EOS data files. Two measure-ments, speed and compression ratio(CR), were used as the comparisoncriteria. The algorithms evaluated werethe CCSDS lossless data compression(Sz), Gzip (Gz), Unix compress (Cz),and JPEG Arithmetic coding (Az). Theywere tested on a Sun Sparc20 worksta-

tion running the Unix operatingsystem. The prototype study resultsdemonstrated that CCSDS lossless datacompression was superior to the othertechniques in compression ratio andcompression speed. Table 1 shows thesummary comparison results. Values inthe table represent the averages over allthe science data products tested.

Between 1999 and 2001, a further studyon the feasibility of using CCSDScompression for real-time processing ofEOS data was performed. Gigabytes ofMODIS real sensor data were tested onan EOS Core System (ECS) operationalmachine. The results showed that theSz compression time on the ECSproduction machine for a typical set ofMODIS products (one granule includ-ing 1-km, 500-m and 250-m resolutiondata) was about 3 minutes. In compari-son, it took almost one hour to com-press the same data sets using Gzip.Only the Sz compression speed wassuitable for the ECS operations, sincethe compression time per granulewould be relatively small (~10%)compared to the time required togenerate one granule of Level-1B datafrom Level 0 data. A scalability analysis

CCSDS Lossless Data Compression to be Available inHDF-4 and HDF-5— Wei Xia-Serafino, [email protected], NASA Goddard Space Flight Center / GST— Ben Kobler, [email protected], NASA Goddard Space Flight Center— Pen-shu Yeh, [email protected], NASA Goddard Space Flight Center

Sz Gz Cz Az

CR

Compress (seconds)

Decompress (seconds)

3.24

353

394

2.44

8112

1264

2.06

1973

790

2.38

10516

7341

Table 1. Phase I Result Summary


20

model was established by DanielMenasce (George Washington Univer-sity) to assess the cost savings of usingCCSDS lossless data compression in theECS operational system. The analysiswas done based on the data volumesarchived and distributed at the GSFCDAAC. The scalability model wasused to assess cost savings of using Szas a data compression algorithm in twoscenarios: (1) SZDC - compress beforestoring and distribute in compressedform; and (2) SZDU - compress beforestoring and uncompress beforedistributing. SZDC saves bandwidthand network transmission time overSZDU but requires users to decompressfiles. It was determined that substantialcost savings could result from the useof hardware tape compression (1.5:1compression) for Level 0 data products,and Sz compression for Level 1 andhigher data products.

Based on the results, ESDIS recom-mended implementing the lossless datacompression algorithm, Sz into theNational Center for SupercomputingApplications (NCSA) Hierarchical DataFormat (HDF) library. EOSDIS usesHDF-EOS, an extension to HDF, forarchiving and distributing EOS data.HDF includes I/O libraries and toolsfor analyzing, visualizing, and convert-ing scientific data. The current versionof HDF-4 already supports lossless datacompression algorithms – Run LengthEncoding (RLE), Skipping Huffman(SKPHUFF), and Gzip compression(Lempel/Ziv-77 dictionary coder,named Deflate). The current version ofHDF-5 supports Gzip compressiononly. Implementing the CCSDS losslessdata compression into the HDF libraryprovides a transparent method forusers to capitalize on reduced datavolumes since the HDF library containsan interface for storing and retrievingcompressed or uncompressed data.

After two years of collaborationbetween NASA, NCSA, and theUniversity of Idaho (the current licenseholder of the Sz license), CCSDSlossless data compression will now beincorporated into HDF. HDF-5 Release1.6, to be released in June, 2003, willinclude support for CCSDS losslessdata compression (Sz), along with thesupporting utility programs. The nextrelease of HDF-4, to be released insummer 2003, will also include supportfor Sz.

Pre-configured and pre-compiled HDFbinaries will have Sz enabled, and willsupport data sets with 1-24 bits/pixel,32 bits/pixel, and 64 bits/pixel. Szsource code and Sz binaries will also beavailable for download from NCSA.Applications will enable Sz by settingan optional filter when a dataset iscreated. Once enabled, data will beautomatically compressed and decom-pressed with Sz during I/O. Szdistributed with HDF products will befree for non-commercial use, to bothencode (compress) and decode(uncompress) data. Commercial users,however, may use the software only todecode data, and will need to acquirecommercial licenses to distribute an Sz-based encoding software product.

Further details on Sz usage will beavailable from the NCSA HDF web site.


21

On April 26, 2003, the Aqua ProjectScience Office, along with the NASAGoddard Space Flight Center Educa-tion Programs Office, EOS MissionOperations Office, Morgan StateUniversity, DuVal High School, and theBaltimore Museum of Industry,sponsored the Aqua EngineeringCompetition for High School students.The competition consisted of tworounds of problem solving, a qualifyinglong-term problem where teams had 10weeks to solve a real-world Aquaproblem, and a short-term hypotheticalproblem that had to be solved in 90minutes.

In the competition’s first round, teamsfrom within Goddard’s service region(Washington D.C. to Maine) were askedto determine the likely cause of asudden increase and decrease thatoccurred in Aqua’s solar array currentand resulted in the spacecraft enteringinto “safe mode” during its first monthof operation. A total of 12 entries werereceived and evaluated and the top fiveteams were selected as finalists. Thesefinalists were then invited to DuValHigh School for the second and finalround of the competition, whichoccurred on April 26. Four high schoolteams from Maryland and one teamfrom Connecticut were the five finalistsand were tasked with determining howbest to operate a supposed malfunc-tioning Solid State Recorder (SSR),including calculations for data lossbased on specific SSR temperatures andbit error rates. The five finalist teams

analyzed, sorted, and crunched datausing their problem-solving skills, thenused a laptop to make a finalPowerPoint presentation to the judgingpanel.

After the presentations were made, allthe teams, parents, judges and facilita-tors made their way across the street tothe Goddard Visitor Center whereeveryone was treated to lunch andpresentations by the sponsoringagencies. Meanwhile, the judges werehidden away to tally up the round twoscores and ultimately determine thewinners. At the end of the day, all theteams and parents were treated to apersonal tour of the EOS MissionOperations Center, hosted by PaulOndrus, the EOS Mission OperationsDirector.

The Grand Prize, a state-of-the-art PCor Apple Macintosh computer systemcomplete with a large assortment ofsupporting software, was awarded tothe six-member team of Perry HallHigh School in Baltimore, Maryland.

The First Runner-Up team, from theApplications and Research LaboratoryHigh School (Red Team) of Ellicott City,Maryland, was also awarded a PC orApple Macintosh system with software.

Tourtellotte Memorial High School ofGrosvenordale, Connecticut, placed avery impressive third, and ChopticonHigh School of Morganza, Maryland,and DuVal High School of Lanham,Maryland, rounded out the field of

very impressive teams. In addition tothe first and second place awards, PalmPilots, shirts, and well-deservedtrophies were given to all members ofall five finalist teams.

NASA congratulates all the teams forimpressive performances during anenjoyable day of competition andeducation. Many thanks to the follow-ing key contributors for all their hardwork: Claire Parkinson, Aqua ProjectScientist; Ken Anderson, Aqua Engi-neer; Steve Graham, Aqua OutreachCoordinator; Ron Erwin, GoddardEducation Programs Office; AnaSwamy, Morgan State University;Eugene Hoffman, Morgan StateUniversity; Dereje Seifu, Morgan StateUniversity; Susan Maule, BaltimoreMuseum of Industry; Lynn Hardin,DuVal High School; and finally PaulOndrus, EOS Mission OperationsDirector, for graciously providing thefunding for the competition.

Aqua Mission Sponsors 2003 Engineering Competition

— Steve Graham, [email protected], Aqua Outreach Coordinator, Goddard Space Flight Center— Claire Parkinson, [email protected], Aqua Project Scientist


22


23

The Strategic Evolution of EarthScience Enterprise Data Systems(SEEDS) group held its third publicworkshop in Annapolis, Maryland, onMarch 18–20, 2003. With nearly 100 inattendance, from government agencies,private industry, and universities, thiswas our most well-attended andsuccessful workshop to date. The twoprimary goals of this workshop wereto:

1) give the data provider andscience user communities theopportunity to respond inperson to the draft set ofrecommendations preparedby the SEEDS FormulationTeam;

2) and to begin dialog on thenext phase of formulation:preparation for implementa-tion of a SEEDS ProgramOffice.

The draft set of recommendations wasreported in the November / December2002 Earth Observer, and stems from thework of seven study teams who weretasked to look at a specific aspect ofdata systems in a distributed, heteroge-neous environment (namely, levels ofservice, standards for near-term andlonger-term missions, data lifecycle andlong-term archive, reuse, and referencearchitectures, technology infusion, andmetrics planning and reporting). Eachstudy team had a set of objectives andassembled a team representative ofdata-service providers, users, and otherdata-systems experts. Members of theEarth Science Information Partner

(ESIP) Federation were involved inevery study team, and contributedgreatly to the development of therecommendations. While the formalcomment period has expired, the draftis still available via the SEEDShomepage (lennier.gsfc.nasa.gov/seeds/

index.html), and comments are alwayswelcome.

Eighty-nine items were sent in over thecourse of the four months that therecommendations were officially openfor comment. Comments ranged fromgeneral agreement or disagreementwith certain points to specific wordingsuggestions. All comments arecurrently being processed, and answersto each comment will be sent back tothe originator.

Mary Cleave, Deputy AssociateAdministrator for Earth Science(Advanced Planning), opened themeeting with a presentation aboutCode Y’s plans for the next decade.Martha Maiden, Program Executive,presented the status of the dataroadmap being created by Code Y as away to link data activities to research,applications, missions, and other CodeY activities. Then Stephen Wharton,SEEDS Formulation Manager, pre-sented his goals for the workshop.Other invited speakers included Dave

Jones, President of the ESIP Federation,who spoke about Federation goals andareas for cooperation with SEEDS;David Etter from the Bay Area SharedInformation Consortium (BASIC), whopresented his work on standards;

William Johnston, senior scientist atLawrence Berkeley National Labora-tory, who spoke about the Global GridForum standards development process;Cheryl Craig from the HIRDLS project,who spoke from the science teamperspective about lessons learned indeveloping standards; and Joseph

Coughlan from NASA Ames ResearchCenter, who talked about technologyinfusion efforts in his organization. Allpresentations from this workshop areavailable via the link to the thirdworkshop.

For the Formulation Team, workcontinues. After completing the DraftRecommendations Document, the teamwill be busy welcoming the Research,Education, and Applications SolutionsNetwork Cooperative AgreementNotice (REASoN CAN) awardees to theworking groups, finalizing theircharters, and beginning their work. Weare also planning for a workshop in thefall to welcome the REASoN winnersand bring them up to speed on SEEDS.

SEEDS Update

— Kathy Fontaine, [email protected], NASA Goddard Space Flight Center


24

KudosGlaciers and a Stream Named for EOS Scientists

Feature Name: Bindschadler GlacierLatitude: 77º58´S; Longitude: 162º09´EDescription: A glacier in the Northwest part of Royal Society Range, Victoria Land, flowing north between Table Moun-tain and Platform Spur to join Emmanuel Glacier. Named by US-ACAN in 1992 after glaciologist Robert A.

Bindschadler of the NASA Goddard Space Flight Center; from 1983 a principal investigator for the United StatesAntarctic Research Program (USARP) studies of the West Antarctic Ice Sheet, including dynamics of ice streams in theSiple Coast area, their interaction with the Ross Ice Shelf, and the role of polar ice sheets in global climate change.Bindschadler is a member of the Landsat TM Instrument Team.

Feature Name: Bindschadler Ice StreamLatitude: 81º00´S; Longitude: 142º00´WDescription: An ice stream between Siple Dome and MacAyeal Ice Stream. It is one of several major ice streams drainingfrom Marie Byrd Land into the Ross Ice Shelf. The ice streams were investigated and mapped by USARP personnel in anumber of field seasons from 1983-84 and named Ice Stream A, B, C, etc., according to their position from south tonorth. The name was changed by US-ACAN in 2002 to honor Robert A. Bindschadler.

Feature Name: Shuman GlacierLatitude: 75:154S; Longitude: 139:304WDescription: Glacier about 6 miles long draining through the Ruppert Coast north of Strauss Glacier. Named by US-ACAN after Christopher A. Shuman, NASA Goddard Space Flight Center, Greenbelt, MD, a field and theoreticalresearcher in the West Antarctic Ice Stream area from the 1990s to present. Shuman is a member of the IceSAT Instru-ment Team.

The Earth Observer staff and the entire science community wish to congratulate Drs. Bindschadler and Shuman for theseoutstanding accomplishments.

National Academy of Sciences Election

The National Academy of Sciences recently announced the election of 72 new members and 18 foreign associates from11 countries in recognition of their distinguished and continuing achievements in original research. Among thosehonored was Judith L. Lean, a research physicist in the space science division of the Naval Research Laboratory,Washington, DC. Lean is a member of the SORCE Science Team.

The Earth Observer staff wishes to congratulate Dr. Lean on this outstanding accomplishment.


25

Earth’s Hidden Waters Tracked by GRACE

— Alan Ward, [email protected], EOS Project Science Office, NASA Goddard Space Flight Center / SSAI

The Gravity Recovery and Climate

Experiment (GRACE) mission, the first

Earth System Science Project (ESSP)

mission launched by NASA in March of

2002, will produce extremely accurate

maps of the Earth’s gravity field. This

information may be used to track changes

in continental water storage on a global

scale. GRACE is able to sense changes in

the Earth’s gravity field over a given time

period. Changes in the Earth’s gravity field

arise in response to changes in the mass

distribution both on and beneath the

Earth’s surface. It turns out that water

movement (both of surface water and

groundwater) is one of the major causes of

fluctuations in mass on the Earth’s surface.

Thus, if the effects of other causes of mass

change (the atmosphere, the oceans, and

rebound from the weight of glaciers) can be

removed, one should be able to deduce

water storage changes over the continents

from a gravity measurement. Introducing

additional model information on soil

moisture and other components of the total

water storage may allow for the portion of

the total water storage change attributable

to groundwater (aquifer) changes to be

isolated, which could be extremely useful in

places where monitoring networks are

sporadic or nonexistent and be a very

powerful new tool for applications such as

water resource planning.

Introduction

Viewed from above, our home planet isa “blue marble” with an abundance ofwater on its surface. Yet, only a smallamount of this water is fresh andsuitable for consumption by plants,animals, and humans. Potable water

availability, quality, and conservationissues impact every nation on Earthand are becoming ever more importantas population increases and othernatural and manmade changes placemore and more demand on theseprecious resources. Surface waterincludes both flowing water in streamsand rivers, and impounded water insoil (soil moisture), natural lakes, polarice caps, and manmade reservoirs. Italso includes important seasonalvariations caused by annual snowfall.Groundwater is the other component oftotal water storage and includes thelarge amounts of water stored beneaththe Earth’s surface in aquifers. Besidessupplying water for drinking and otherdomestic uses, surface and aquiferwaters are essential for power genera-tion and irrigation. Plants and animals

also depend on soil moisture andsurface water. Furthermore, groundwa-ter sustains streams between episodesof surface runoff, and snowmeltrecharges the other stocks of water.

Since water availability is such a vitalsocietal need, it is very important tobetter quantify water storage changesover the continents, particularlychanges in groundwater storage. Forexample, it is well documented that thewater level of the High Plains aquifer,which encompasses a large portion ofthe Midwestern U.S., has been steadilydeclining for the past few decades andit is believed that similar scenarios areplaying out all over the world. Theculprit is overuse; more water is takenout each year to meet the growingneeds of society than is replenished by

Figure 1: The pie graph shows that only a very small portion of the Earth's water is fresh. The closeupshows the breakdown of the fresh water supply. Almost a third of the world's fresh water isgroundwater — stored in underground aquifers. Hence, GRACE's expected ability to monitor changesin these unseen water reserves from space is very significant.


26

nature. To date, however, the influenceof climate and meteorological phenom-ena on water storage changes is notwell understood, and as a resultmodels still do a poor job of represent-ing water storage changes. In largepart, this is due to a lack of reliableinformation. Historically, it has provenvery difficult to develop networks forgathering terrestrial water storage data.And even the data that do exist are notreally sufficient. Current ground-basedwater storage measurement techniquesare labor intensive and provide onlypoint estimates of water storage. As aresult, most of the world’s aquifersystems are not surveyed regularly andmethodically, which renders assessingregional changes in groundwater levelstedious or impossible.

Remote sensing has been touted as apossible solution to this problem. Thevantage point of space allows forglobal- and synoptic-scale measure-ments to be obtained, and makes itmore practical to track water storagechanges on a larger scale. The Ad-vanced Microwave Scanning Radiom-eter for EOS (AMSR-E) onboard theAqua spacecraft, for example, has thecapability to examine surface soil

moisture from orbit and will result inimproved representation of surface soilwater storage in models. However, it isunable to penetrate beyond the top fewcentimeters to sense deeper soilmoisture or groundwater.

Researchers will soon have a new toolto study subsurface water storagefluctuations in their arsenal. Their newweapon comes from what might at firstseem like an unlikely source. In Marchof 2002, NASA launched GRACE — thefirst of the ESSP missions. Its five-yearmission is to map the Earth’s gravityfield with unprecedented accuracyevery 30 days.

Gravity 101

If Earth were a smooth sphere com-posed of similar elements or ingredi-ents, there would be no need for aGRACE mission. The assumption madein most introductory physics coursesthat the acceleration due to Earth’sgravitational field has a constant valuewould indeed be correct — end ofstory. The reality, however, is that Earthis anything but smooth and uniform,and the gravity field is continuallychanging, mostly due to variations inwater content as it cycles between the

atmosphere, oceans, continents,glaciers, and polar ice caps. GRACEwill reveal the broad features of theEarth’s gravitational field over landand sea; it will also allow for thesesmaller scale features to be identifiedand studied with unprecedentedaccuracy and it will show how theEarth’s gravity field varies with time.The unique design of the GRACEmission is expected to lead to animprovement of several orders ofmagnitude in these gravity measure-ments and allow much improvedresolution of the broad to finer-scalefeatures of Earth’s gravitational fieldover both land and sea.

The Earth’s gravity field consists of twocomponents: a mean (or long termaverage) component and a timevariable component. The meancomponent of the gravity field is thatportion of the total gravity fieldresulting from mass distributions thatremain virtually unchanged overmillions of years like the mass of theEarth or the locations of continents —phenomena that are more or lessconstant for purposes of computing thegravitational field. In contrast, the timevariable component of the gravity fieldis that portion of the gravity signalcaused by mass fluctuations that occuron much shorter time scales includingchanges in groundwater, ocean surfaceheight, and atmospheric mass. Al-though the mean gravity field is ofconsiderable value in understandingthe structure of the Earth and helpingto reveal aspects of ocean circulation, itis the time variations in the gravityfield, in particular those caused bywater storage changes, that are ofinterest in this study.

The workings of GRACE

GRACE is different from most Earthobserving satellite missions — Terra

Figure 2: This graph shows that agriculture places the largest demand on the world's available waterresources. Many agricultural applications draw their water from underground supplies. The continuedviability of agriculture in some areas of the world critically dependent on these aquifers.


27

and Aqua for example — because itdoesn’t carry a suite of independentscientific instruments on board. It doesnot make measurements of the electro-magnetic spectrum like many of theinstruments currently flying in space.Instead, the two GRACE satellitesthemselves act in unison as the primaryinstrument. Changes in the distancebetween the twin satellites are used tomake an extremely precise gravita-tional field measurement.

The two identical satellites orbit onebehind the other in the same orbitplane at an approximate distance of 220km (137 miles). As the pair circles theEarth, areas of slightly stronger gravity(greater mass concentration) affect thelead satellite first, pulling it away fromthe trailing satellite. The change indistance would certainly be impercep-tible to our eyes, but an extremelyprecise microwave ranging systemonboard GRACE is able to detect theseminiscule changes in the distancebetween the satellites. A highlyaccurate accelerometer, located at eachsatellite mass center, measures thenon-gravitational accelerations (such asthose due to atmospheric drag) so thatonly accelerations caused by gravityare considered. Satellite GPS receiversdetermine the exact position of thesatellite over the Earth to within acentimeter or less. Scientists can take allthis information, and use it to constructmaps of the gravity field over theEarth’s surface once every thirty daysduring the planned five-year mission.

Tracking water storage change over

continents from space

GRACE data will do more than justproduce a more accurate gravitationalfield plot, however. The measurementsfrom GRACE have important implica-tions for improving the accuracy of

many scientific measurements relatedto climate change—hence, GRACE isalso a climate experiment as its nameimplies. Accurate gravitationalmeasurements are a critical input tomany scientific models used inoceanography, hydrology, geology, andrelated disciplines and, for this reason,the Earth Science community is excitedabout potential applications forGRACE data. One of the most intrigu-ing uses of data is expected to be usingdata from GRACE to track changes inwater storage over terrestrial regions.

Matt Rodell at the Goddard SpaceFlight Center and Jay Famiglietti at theUniversity of California at Irvine havedone extensive work to prove thisconcept, following up on work that hadbeen done by John Wahr at the Univer-sity of Colorado. Wahr demonstratedthe potential for using GRACE data tomonitor water storage by deriving asimulated GRACE gravity field andthen separating out the water storagecomponent of the signal. Rodell andFamiglietti’s work used 10 modeledglobal time series of water storage tostudy water storage change for 20 riverbasins of varying size around the worldand determined how successfulGRACE will be in detecting thevariations. The findings indicate thatdata from GRACE should be able to beused to decipher monthly waterstorage changes over continents forareas of approximately 200,000 km2 orlarger. They then conducted a studyover the state of Illinois. Illinois has anarea of 145,800 km2 (below the mini-mum threshold for GRACE to detectmonthly water storage changes) but ithas the advantage of having a ratherextensive record of observed data. Theresults in Illinois had to be scaled up tolarger regions by assuming conditionsin the surrounding area are similar tothose in Illinois. Again, the results were

encouraging and indicated thatGRACE should be able to detectmonthly water storage changes overareas larger than 200,000 km2. Rodelland Famiglietti are excited to seeGRACE data begin to flow thissummer, so that they can verify theirfindings with actual data.

GRACE measurements by themselves,however, are not able to distinguishwhether a change in gravity resultsfrom a change in water mass, a changein the mass of the overlying atmo-sphere, or a change in the underlyingsolid Earth. Outside information isneeded to estimate the contribution ofthe other components to the totalgravity measurement. To measurewater storage changes using theGRACE-technique, monthly averagegravity fields are desired. Therefore,any gravity variations with a timescaleof a month or less have to be removedbefore the data is released for use,during the calculation of the originalorbit and gravity solution. The GRACEscience team uses a complex atmo-spheric model and an ocean model toaccount for changes in gravity thatarise from such phenomena as oceantides and the atmosphere-a techniqueknown as dealiasing. This can bethought of as "correcting" the rawgravity field for the effects of the dailyweather.Now, the gravity measurement is readyfor use in hydrological applications.Any variations that remain have atimescale of one month or larger (equalto or greater than the phenomena beingobserved) and can be dealt with byscientists after they receive the datafrom the GRACE science team. Usingvarious model simulations of theatmosphere and the solid earth, theeffects not attributed to changes inwater storage can be removed and the"corrected" gravity field now represents


28

only the portion that is attributed to themass of water stored in a particularregion at a given time. This can then beconverted to an equivalent waterheight. Two of these measurementstaken at different times can be used tostudy changes in water storage in aparticular region.Sources of Error

But it’s not really as simple as subtract-ing the other components from the totalgravity measurement. It would be assimple as that if these models wereperfect representations of actualconditions—but they aren’t. Eachmodel used in this process is just asimulation of the actual conditions andthus less than perfect. There has to besome way to account for how muchthese model imperfections impact thefinal water storage measurement. So,what the scientists have to do is devisea way to look at how much error eachof the external models used in thiscalculation introduce to the final totalwater storage estimate. A GRACEwater storage estimate could berendered useless if the total errorintroduced by removing these othercomponents is greater than themagnitude of the actual water storageestimate.

In addition to errors introduced byremoving each of the other componentsof the total gravity measurement, theGRACE instrument itself introduces yetanother source of error due to all of itsvarious mechanical components. So tofigure out the total error introduced tothe water storage estimate, one has toaccount for the combined effects of thevarious model estimates and theinstrument itself. It turns out that, ingeneral, the instrumental errors are theprimary impediment to using theGRACE-technique to estimate waterstorage in areas smaller than 200,000

km2 and over shorter time scales.Atmospheric mass errors becomedominant at larger scales, but aren’tlarge enough to prevent the retrieval ofmeaningful water storage changemeasurements.

Limitations to the Technique

Because it takes time for the GRACEsatellites to fly over parts of the Earth,the total magnitude of the waterstorage change at an instantaneoustime cannot be determined using thistechnique. Only the change in waterstorage over a given region for a giventime interval is obtainable. So, as anexample, one could use this techniqueto examine the change in water storageover the Mississippi River basin duringa chosen time interval, but one couldnot determine the height of the watertable in the Mississippi River basin atthe specific time the measurement wasobtained. In fact, in order to determinewater storage change over a region,GRACE measurements from twodistinct time periods must be used.

Rodell and Famiglietti’s two studiesconsidered areas ranging in size fromthe state of Illinois up to entire riverbasins such as the Amazon and theMississippi and looked at monthly,seasonal, and yearly time intervals forall of these regions. They found that,generally speaking, the plannedGRACE-technique will be moreaccurate for larger areas over longertime intervals. For example, an area thesize of Illinois (145,800 km2) willusually not be able to have month-to-month water storage changes detectedusing the GRACE-technique, but it ismore likely to have seasonal (three-month periods) changes detected, andeven more likely to have annualchanges detected. In contrast, an area

the size of the Mississippi River basin(3,165,500 km2) will likely be able tohave water storage change detected atmonthly, seasonal, and annual timeintervals. As one might expect, themethod will be most effective when theactual magnitude of the change beingobserved is large. So, even in largerareas, the GRACE-technique will bemost effective when there is a largeamount of variability in water storageover the chosen time interval. In manylocations, changes between seasonshave the highest magnitude, and thusseasonal water storage change may beeasiest to detect using the GRACE-technique.

Honing in on groundwater

When combined with still more outsideinformation from other sources, theGRACE-technique may be taken a stepfurther and used to focus in ongroundwater changes. This raises thevery exciting possibility of allowingchanges in aquifer water storage to betracked from space. Rodell andFamiglietti have demonstrated thispotential by examining data from theU.S. High Plains region. In order toisolate the groundwater component oftotal water storage change, the contri-bution from all of the other compo-nents to total water storage changehave to be determined and removed.The main contributors to total waterstorage change over continents arechanges in soil moisture, snow water,and reservoir storage (meaning, surfacewater that is restrained and wellmonitored). In the work they did inIllinois, the two scientists found thatthe contributions to the total waterstorage change resulting from reservoirstorage (not including unregulatedsurface water flow as of yet) and snowwater were usually insignificant


29

relative to changes in soil moisture andground water. They make the assump-tion that the same is true of the HighPlains region. That leaves soil moistureas the sole component that has to beremoved to get at elusive groundwaterchanges. It turns out that the U.S. HighPlains, unlike most aquifers around theworld, has been well sampled andstudied, meaning that lengthy timeseries of soil moisture change exist.This allows for soil moisture changeover time to be estimated fairlyaccurately using models. The soilmoisture contribution can be removedand the remaining change in waterstorage is that resulting from changesin groundwater.

Further refinements should allow forincreasingly accurate estimates ofgroundwater storage using theGRACE-technique. As time progresses,soil moisture simulations will becomemore and more realistic as data fromadditional sources (such as AMSR-Eand new surface observations) areassimilated into the models. Futureefforts will also separate water storedin the so-called intermediate zone(between the lowest level of soilmoisture modeled and the top of thewater table), isolating the groundwatercomponent even more accurately.Intermediate zone storage is still notwell understood and more work isneeded to refine our understanding ofthis component of total water storageso that it can be represented realisti-cally in models. Finally, the proposedfollow-on mission to GRACE willreplace the current microwave rangingsystem with a laser interferometer,greatly reducing instrumental errors,and allowing viable measurementsover areas as small as 10,000 km2.

Using modeled soil moisture adds yetanother source of error that must be

accounted for when attempting to usethe GRACE-technique to isolatechanges in groundwater from the totalwater storage change. In actuality, overan area the size of the High Plains, theerror in the soil moisture estimate turnsout to be the largest source of error—dominating atmospheric mass modelerror and instrumental effects men-tioned above. However, the error doesnot appear large enough to render theGRACE-technique ineffective.

Conclusion

From its satellite platform far above theEarth, GRACE will likely provideestimates of groundwater storagechanges all over the world. Preliminarystudies have shown that the GRACE-technique will allow for estimates ofannual groundwater change over theHigh Plains to within about 8.7 mm oftheir actual value. While there is somequestion whether this represents amajor improvement for a denselymonitored aquifer like the High Plainsaquifer, as mentioned above, mostaquifers around the world are notnearly as well sampled as the HighPlains aquifer. What’s more, even overmore extensively sampled areas, theprospect of a technique that is lesslabor intensive and does not require anextensive network of wells that is equalto or perhaps slightly better than whatis currently available is quite intrigu-ing. GRACE may help to revealgroundwater depletion in areas of theworld where it is not systematicallydocumented or where it is not dis-closed for political reasons. Overall, theGRACE-technique seems to offer anobjective, unbiased method formonitoring water storage changes on aglobal scale.

As this new information from GRACEbecomes assimilated into forecast

models, the simulations produced willbecome more and more realistic anduseful for predicting future conditions.This will lead to forecasts with in-creased accuracy and longer lead times,so that by decade’s end water resourceplanners will have access to much moredetailed and dependable informationthan they have at present. This willlead to improved ability to regulatewater resources and make sure thatsufficient quantity is present for themany needs of society—irrigation foragriculture, municipal supplies, andindustry, just to name a few. It shouldalso lead to rather substantial improve-ments in our ability to predict, plan for,and respond to extreme events, such asfloods and drought.


30

Over 13,000 students, coaches, parents,and spectators gathered at the Univer-sity of Iowa in Ames, May 28-31 for the24th Annual Odyssey of the Mind WorldFinals, an international event whereteams come together to compete for theWorld Championship in their long-term problem and division. Through agrant, NASA’s Earth Science Enterprisesponsored a problem titled “A Scenefrom Above,” one of the five long-termproblems associated with this year’scompetitions. The students werechallenged to design, build and runthree small vehicles to transport itemsfrom an orbit area to an assemblystation in space. The vehicles wereadded to a three-dimensional represen-tation of a scene of the Earth as viewedfrom space, and as the vehicles wereadded, the scene changed. The vehicleswere required to be powered indifferent ways; one vehicle carrying itsown energy source while the other twovehicles were powered by the momen-tum created by different sources.

During the 2002/03 school yearmillions of kids from across the worldbrainstormed, built, revised andperfected their solutions with the hopesof advancing from regional and stateassociation tournaments to the WorldFinals. A total of 127 teams competedfor the top awards in the NASA-sponsored problem. Following are thefirst, second and third place winners ineach Division:

Division 1

1. Sharon Elementary School,Team A, Charlotte, NorthCarolina

2. McKinley School, Rydal,Pennsylvania

3. Mantua Elementary School,Team B, Fairfax, Virginia

Division 2

1. Friendswood Junior HighSchool, Friendswood, Texas

2. Churchville-Chili Interna-tional School, Team A,Spencerport, New York

3. Shorecrest Preparatory School,Largo, Florida

Division 3

1. Myers Park High School,Green Team, Charlotte, NorthCarolina

2. Brien McMahon High School,Norwalk, Connecticut

3. Pennridge High School, GreenLane, Pennsylvania

Division 4

1. Osrodek PsychoedukacjiIDamb, Gdansk, Poland

2 . Georgia Tech University,Atlanta, Georgia

3 . Lehigh University,Bethlehem, Pennsylvania

The Odyssey of the Mind and NASApartnership is a natural collaboration.Both organizations represent the best ininnovation, teamwork and creativeproblem solving. ESE hopes to inspiresome of those students to becomefuture scientists and engineers. Moreinformation on the Odyssey of theMind World Finals can be found atwww.odysseyofthemind.com/wf2003

NASA’s Earth Science Enterprise Sponsors CreativeProblem Solving Competition

— Charlotte Griner, [email protected], EOS Project Science Office— Steve Graham, [email protected], EOS Project Science Office

More than 13,000 students, coaches, parents, and spectators filled the Hilton Coliseum on Saturdayevening, May 31 for the Odyssey of the Mind awards presentation and ceremonies.


31

New Investigator Program (NIP)

Proposals Due: August 15, 2003

The New Investigator Program (NIP) inEarth science was established in 1996 toencourage the integration of Earthsystem science research and educationby scientists and engineers at the earlystage of their professional careers. Theprogram, designed for investigators inEarth system science and applicationsat academic institutions and non-profitorganizations, emphasizes the earlydevelopment of professional careers ofthese individuals as both researchersand educators. The program encour-ages scientists and engineers todevelop a broader sense of responsibil-ity for effectively contributing to theimprovement of science education andthe public science literacy; it providesan opportunity for the investigators todevelop partnerships and enhance theirskills, knowledge, and ability tocommunicate the excitement, chal-lenge, methods, and results of theirwork to teachers, students, and thepublic. Of particular interest is theinvestigators' ability to promote andincrease the use of Earth remotesensing through the proposed researchand education projects.

NIP proposals are openly solicitedapproximately every 18 months. Theawards range between $80,000-$120,000per year for a period of up to threeyears, For more information, seeresearch.hq.nasa.gov under "Office ofEarth Science (Code Y)." For more

information, please contact Dr. Ming-Ying Wei, Manager, Education Pro-grams, Office of Earth Science,[email protected].

NSF Program Announcement for

EarthScope Proposals

Proposal Deadline: July 16, 2003

The National Science Foundation (NSF)has released a Program Announcementinviting proposals for EarthScopeScience, Education and RelatedActivities. Full details are available at:www.nsf.gov/pubs/2003/nsf03567/

nsf03567.htm.

The EarthScope facility (USArray, SanAndreas Fault Observatory at Depth[SAFOD]), and Plate BoundaryObservatory (PBO) is a multi-purposearray of instruments and observatoriesthat will greatly expand the observa-tional capabilities of the Earth sciencesand help advance understanding of thestructure, evolution, and dynamics ofthe North American continent. TheEarthScope observational facilityprovides a framework for broad,integrated studies across the Earthsciences.

Director, The GLOBE Program

The University Corporation forAtmospheric Research (UCAR) has anopening for the position of Director,Global Learning and Observations toBenefit the Environment (GLOBE)Program. The GLOBE Program is a

worldwide hands-on, primary andsecondary school-based education andscience program. It is a cooperativeeffort of schools, led in the U.S. by aFederal interagency program andsupported by NASA, the NationalScience Foundation (NSF), the Environ-mental Protection Agency (EPA), andthe U.S. State Department, in partner-ship with colleges and universities,state, and local school systems, andnon-government organizations.Internationally, GLOBE is a partnershipbetween the United States and 102other countries. For full positiondescription, see www.fin.ucar.edu/hr/

careers/uco.cfm?do=jobDetailExt&job_ID=

72.

U.S. Global Change Research Program

Website — New and Improved

The U.S. Global Change ResearchProgram has just updated its "New"page with a wide-ranging set oforganized links to new online material.The page is usually updated monthlyand provides an easy way to monitorimportant scientific developmentswithout having to dig around dozensof different web sites. See the additionsat www.usgcrp.gov/usgcrp/new.htm.

DLESE K-12 Earth Science Listserves

This web site provides informationabout Earth science/Geoscienceeducation listservs in the United States.See dlesecommunity.carleton.edu/k12/

listservs.

Earth Science Education Program Update

— Ming-Ying Wei, [email protected], NASA HQ— Theresa Schwerin, [email protected], IGES


32

NASA Research Helps Highlight

Lightning Safety Awareness Week,June 19, Aboutweather, Der Wissenschaft

(Germany) - Steven Goodman, Dennis

Boccippio, Richard Blakeslee, Hugh

Christian, and William Koshak (allfrom NASA/Marshall) helped create ahigh-resolution world map showingthe frequency of lightning strikes.

NASA Rainfall Measurement, June 15;The Huntsville Times, (Ala.) - Gary

Jedlovec (NASA MSFC) discusses theCooperative Huntsville Area RainfallMeasurements (CHARM), a localprecipitation-measurement network.

Study Suggests Ancient Oceans Had

Low Levels of Oxygen, June 10,Associated Press, quotes David Des

Marais (NASA/Ames) who is co-author of a study included in the June 5issue of the journal Nature.

Spotlight on Ames Researcher, June 3,Chicago Tribune, column about NASAresearcher Azadeh Tabazadeh (NASA/Ames)

Jet Writers in the Sky, June 2, Knoxville

News Sentinel, knoxnews.com - Pat

Minnis (NASA Langley) speaks aboutthe contrail studies conducted duringthe 2001 air traffic shutdown.

NASA’s Aqua Satellite Marks One

Year, May 29, Spacedaily.com - Claire

Parkinson, Aqua Project Scientist(NASA/GSFC) was quoted in thisarticle on Aqua’s first year. Aquaprovided views of fires, snowstorms,typhoons, a volcanic eruption and duststorms.

QuakeSim, May 27, KTVU-TV, CH 2

Oakland; May 22, KNBC-TV, Los Angeles,

CA — Walt Brooks and Creon Levit

(NASA Ames) were interviewed abouthow JPL ‘QuakeSim’ program softwarewill run on the biggest parallelsupercomputer of its kind in the worldat NASA Ames.

Students at Ames, May 24 and 25,KCBS-AM, San Francisco - Jay Skiles

(NASA/Ames) was interviewed aboutstudents who will study Earth Scienceat Ames this summer.

Precipitation in the Southern U.S.,May 20; WHNT-TV Channel 19,

Huntsville Ala. - John Christy, Gary

Jedlovec and Bob Oglesby (NASAMSFC) discuss precipitation anddrought in the Southern United States.

Potential Pollution Dangers of the Air

In Baghdad Due to Burning Oil, Thick

Smoke and Sandstorms, March 27,

National Public Radio’s, “All Things

Considered” - Joel Levine (NASALangley) discusses the environmentalimpact of the burning Iraqi oil wells.

— Robert Gutro, [email protected],NASA Earth Science News Team


33

EOS Science Calendar Global Change Calendar

July 21 - 22, 2003

SEDAC User Working Group meeting, NewYork, NY. Contact: Robert Chen,[email protected].

July 28 - August 1

“Earth Science for Safety” — 11th meetingof the ESIP Federation, Boulder, Colorado.URL: www.esipfed.org, Contact: DaveJones, [email protected]

September 23 - 25

HDF & HDF-EOS Workshop VII , SilverSpring, MD. Call for abstracts. Contact:Richard Ullman, [email protected]. URL: hdfeos.gsfc.nasa.gov

September 23 - 25

CERES Science Team Meeting, Hampton,Va. Contact: Gary Gibson, [email protected].

September 30

Aura Science Team Meeting, Pasadena, CA.Contact: Anne Douglass, [email protected].

October 15

SEDAC User Working Group meeting,Montreal, Canada. Contact: Robert Chen,[email protected].

December 4-6

SORCE Science Team Meeting, Sonoma,CA. Contact: Bob Cahalan,

Robert.F.Cahalan@nasa. gov.

2003

July 21 - 25

IGARSS 2003, Toulouse, France. Email:[email protected], URL: www.igarss03.com.

August 30 - September 6

Second International Swiss NCCR ClimateSummer School: “Climate Change —Impacts of Terrestrial Ecosystems.”Grindelwald, Switzerland. Contact: KasparMeuli, Email: [email protected],URL: www.nccr-climate.unibe.ch.

September 8 - 10

Sixth Baiona Workshop on SignalProcessing in Communications, Baiona,Spain. Contact Carlos Mosquera, Email:[email protected], URL:www.baionaworkshop.org

September 23 - 26

Oceans ‘03, San Diego, CA. Contact: BrockRosenthal, Email: [email protected],Tel: (858) 454 4044, URL: www.o-vations.com.

November 10 - 14

30th International Symposium on RemoteSensing of Environment, Honolulu, HI.Email: [email protected], URL:www.symposia.org.

December 9-12

American Geophysical Union (AGU) SanFrancisco. E-mail: [email protected]: www.agu.org/meetings/fm03/

2004

January 11-15

American Meteorological Society AnnualMeeting, Seattle, Wa. URL:www.ametsoc.org.

February 24-27, 2004

8th Specialist Meeting on MicrowaveRadiometry and Remote SensingApplications, Rome, Italy. URL:www.microrad04.org

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The Earth Observer

The Earth Observer is published by the EOS Project Science Office, Code 900, NASA Goddard Space Flight Center,Greenbelt, Maryland 20771, telephone (301) 614-5559, FAX (301) 614-6530, and is available on the World Wide Web ateos.nasa.gov/ or by writing to the above address. Articles, contributions to the meeting calendar, and suggestions arewelcomed. Contributions to the calendars should contain location, person to contact, telephone number, and e-mailaddress. To subscribe to The Earth Observer, or to change your mailing address, please call Hannelore Parrish at (301)867-2114, send message to [email protected], or write to the address above.

The Earth Observer Staff:

Executive Editor: Charlotte Griner ([email protected])Technical Editors: Bill Bandeen ([email protected])

Jim Closs ([email protected])Renny Greenstone ([email protected])Tim Suttles ([email protected])Alan Ward ([email protected])

Design and Production: Alex McClung ([email protected])Distribution: Hannelore Parrish ([email protected])

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