nasa activities and plans in water cycle...

Matt RodellNASA GSFC

NASA Activities and Plans in Water Cycle Research

Matt Rodell

Chief, Hydrological Sciences LaboratoryNASA Goddard Space Flight Center


NASA Earth Science MissionsCurrent & Planned

Highly relevant to hydrology


Global Precipitation Measurement (GPM)

• Global (50S-50N) precipitation measurement

– 10 85 GHz radiometers – 13.6 GHz precipitation radar– Nov 1997 to Apr 2015

• Launched Feb 28, 2014• Uses inputs from an international

constellation of satellites to increase space and time coverage

• Improvements:- Longer record length- High latitude precipitation

- including snowfall- Better accuracy and coverage

Precipitation

Tropical Rainfall Measurement Mission(TRMM)

TRMM 14-year mean rainfall

The GPM Core Observatory will provide improved measurements of precipitation from the tropics to higher latitudes


SMAP Facts• Resolution: 10 km (radar); 25 km (radiometer)• Instruments: L-band Radiometer and (for a couple of months) Radar• Launch: January 31, 2015• Mission Duration: 3 years

Soil Moisture Active Passive (SMAP)

SMAP radar image acquired from data from March 31 to April 3, 2015. Weaker radar signals (blues) reflect low soil moisture or lack of vegetation, such as in deserts. Strong radar signals (reds) are seen in forests.


6 Jan 2013

MODIS cloud gap filled (CGF) fractional snow cover map

Standard MODIS Snow-Cover Map Products

Hall & Riggs, 2007; Hall et al., 2010


Soil MoistureSnow, Ice, Rainfall Snow

VegetationRadiation

Gravity Recovery and Climate Experiment (GRACE)

Aqua: MODIS, AMSR-E, etc.

GRACE

GRACE is unique in its ability to monitor water at all levels, down to the deepest aquifer

Conventional radiation-based remote sensing technologies cannot sense water below the first few centimeters of the snow-canopy-soil column


Routine Lake Level Monitoring (Jason2 & SARAL)

Contacts: Charon Birkett/U. Maryland, Curt Reynolds/USDA/FAS

http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir


Surface Water Mission Concept (SWOT)Stream Discharge and Surface Water Height

Interferometer Concept (JPL)

Laser Altimetry Concepte.g. ICESat (GSFC)

Targeted pathCoincident w/

river reach

Radar Altimetry Concepte.g. Topex/Poseidon over Amazon R.

Motivation:• critical water cycle component• essential for water resource planning• stream discharge and water height data are difficult to obtain outside US• find the missing continental discharge component

Mission Concepts:

Source: M. Jasinski/614.3


The 2017 Decadal Survey in Earth Science will likely dictate NASA’s water cycle mission launches for the next ten years

Community input now being requested water cycle mission priorities should be discussed at this conference

Planned missions: GRACE Follow On (2017); SWOT (2020) Gaps: Evapotranspiration? Snow depth/water equivalent? Another attempt at a soil moisture radar? Precipitation and other continuity missions? New measurement techniques with high risk & high reward? Perhaps a more holistic approach: a series of simultaneous or

consecutive water budget measurements, akin to the A-train? Mission proposals that include shared international investment

(launch vehicle; instruments; sister satellites/constellations) are more likely to be selected

Future NASA Water Cycle Missions


Data Integration Is Critical for Maximizing the Value of Water Cycle Data: LDAS Example

INTERCOMPARISON and OPTIMAL MERGING of

global data fields

Satellite derived meteorological data used as land surface model FORCING

ASSIMILATION of satellite based land surface state fields (snow, soil moisture,

surface temp, etc.)

Ground-based observations used to VALIDATE model output

SW RADIATION

MODIS SNOW COVER

PRECIPITATION

SNOW WATER EQUIVALENTMatt RodellNASA GSFC

Images from NASA’s GLDAShttp://ldas.gsfc.nasa.gov/


Land Data Assimilation Systems

North American LDAS- NOAA, NASA, (and 6 other US institutions) 1998-present- 1/8 degree resolution, central North AmericaGlobal LDAS- NASA (and NOAA) 2000-present- 1/4 and 1.0 degree resolutions, all land 60S-90NLand Information System (LIS)- NASA 2002-present- Software configurable for any domain and resolution- Multiple data assimilation options- Can be run uncoupled or coupled to an atmospheric model- Adopted by all other NASA LDAS projects & NOAA & AFWAOthers: MERRA-Land; European LDAS; Middle East North Africa (MENA) LDAS; South American LDAS; LDAS-University of Tokyo; etc.

Matt RodellNASA GSFCMatt RodellNASA GSFC

NEWS Grand Challenge: To document and enable improved, observationally-based, predictions of energy and water cycle consequences of Earth system variability and change.

Approach: Unlike most research funding programs, NEWS fosters large team collaborations to solve energy and water cycle challenges that would be difficult or impossible for individual investigations to address on their own.

NASA Energy and Water Cycle Study (NEWS)


Premise: In order to evaluate water and energy cycle consequences of climate change, we must establish the current "state of the global water/energy cycle".

Methods: Use modern, observation-integrating products and associated error-analyses to develop a monthly climatology of W&E cycle components for each continental/oceanic to global scale region. The water and energy cycles are closed through simultaneous application of multiple conservation equation constraints, using concepts from the variational data assimilation and optimal estimation retrieval communities.

Outcomes: (1) A benchmark for W&E cycle / climate change studies and model assessments; (2) Constrained energy flux estimates for quantifying the annual cycle of top of the atmosphere, surface, and atmospheric energy balances; (3) Quantitative graphical depictions of the water and energy cycles; (4) Better understanding of where the greatest uncertainties lie and what observations should be targeted for improvement.

NEWS Water and Energy Cycle Climatology


Water Cycle: Primary Data Sources

Variable Dataset Name Contributing RS Instruments

Precipitation GPCP v. 2.2MERRACMAP

SSMI, SSMIS, GOES-IR, TOVS, AIRS, TRMM

Evapotranspiration PrincetonMERRAGLDAS

AIRS, CERES, MODIS, AVHRR, MSU, HIRS, SSU, AMSU, SSMI, SSMIS, ERS1/2, QuikSCAT, GOES-IR, TOVS, TRMM

Runoff U. WashingtonDai and TrenberthMERRAGLDAS

TRMM, GOES-IR, TOVS, SSM/I, ERS, ATOVS

Terrestrial and Oceanic Water Storage Change

GRACE CSR RL05 (Chambers)

GRACE

Atmospheric Convergence QSCATMERRAPWMC

QuikSCAT, TRMM, GRACE, MSU, HIRS, SSU, AMSU, AIRS, SSMI, ERS1/2, MODIS, GOES-IR

Atmospheric Water Storage Change (Fetzer) AIRS, AMSR-E

Ocean Evaporation SeaFlux v. 1.0PrincetonMERRA

SSMI, AVHRR, AMSR-E, TMI, WindSat


115.7 ±6.3

385.3 ±38.9

409.5 ±35.7

49.5 ±6.8

71.2 ±7.1

42.9 ±8.2

46.7 ±19.1 116.5 ±5.1

403.5 ±22.2

449.5 ±22.2

45.9 ±4.4

70.6 ±5.0

45.8 ±4.4

45.8 ±2.1

Global, Mean Annual Water Cycle

When water balance is enforced, uncertainty decreases

Global mean water fluxes (1,000 km3/yr) at the start of the 21st century Best guess estimates from observations and data integrating models

40

40

386

426

11474

40

Trenberth et al. (2011) for comparison

65.5

391

436.5

45.545.5

111

45.5

Oki and Kanae (2006) for comparison


Continental Mean Annual Water Fluxes

Water budget constrained/optimized results: Precipitation (blue), evapotranspiration (red), runoff (green), and annual amplitude of terrestrial water storage (yellow) in 1,000 km3/yr. Background shows GRACE-based amplitude of the annual cycle of terrestrial water storage (cm).


Wat

er F

lux,

mm

/day

‐1

0

1

2

3Global Land

‐1

0

1

2

3

4 Global Ocean

‐2

‐1

0

1

2

3North America

‐2‐101234567 South America

‐1

0

1

2

3

4Eurasia

‐1

0

1

2

3Africa

‐1

0

1

2

3

4Mainland Australia

‐10123456789

10 Australasian and Indonesian Islands

‐1

0

1Antarctica

Optimized Mean Monthly Water Cycle

Mean monthly precipitation (blue), evapotranspiration (red), runoff (green), atmospheric convergence (orange), and month-to-month change in terrestrial water storage (yellow), in mm/day). Shading indicates uncertainty range.


0

1

2

3

4

5

6Precipitation

0

1

2

3

4

5

6Evaporation

‐3

‐2

‐1

0

1

2

3Atmospheric Convergence

Arctic North PacificSouth Pacific North AtlanticSouth Atlantic Indian

Wat

er F

lux,

mm

/day

Optimized Mean Monthly Water Cycle

Mean monthly precipitation, evaporation, and atmospheric convergence over the major ocean basins: Arctic (blue), North Pacific (red), South Pacific (green), North Atlantic (yellow), South Atlantic (orange), and Indian (pink). Shading indicates uncertainty range.


Expected Closure Error

Best Guess Residual

North America 8.6% 11.0%South America 8.0% 5.0%Eurasia 12.5% 5.1%Africa 8.1% 2.1%Australia Mainland 15.0% 7.6%Australasian and Indonesian Islands

19.5% 12.5%

Antarctica 32.4% 0.0%World Land 10.1% 4.3%World Ocean 13.8% 6.6%

How Well Can We Close the Annual Surface Water Budget?

Expected Error after Optimization6.4%5.7%8.7%5.7%9.4%9.9%

17.2%7.2%7.8%

Note the residual after optimization is ~0% in all cases.


• The NEWS W&E Cycle Climatology Team used observation-integrating products and associated error-analyses to develop a monthly climatology of W&E cycle components for each continental/oceanic to global scale region.

• In most cases the original observation-based water budget residual was within the uncertainty range expected based on individual error estimates.

• An optimization process was applied to force closure of the terrestrial, atmospheric, and oceanic water budgets, and the energy budget simultaneously, at mean annual and monthly, global and continental/basin scales. Adjustments were generally smaller than the expected errors.

• The largest adjustments were in the ocean evaporation estimates (~+10%), attributed mainly to energy cycle closure. Adjustments to ocean precipitation (~+5%) were consistent with GPCP error estimates and recent studies (Behrangi et al., 2012; 2014).

• Despite having denser observing networks, residuals tended to be larger over North America and Eurasia than over Africa and South America. This may reflect continuing difficulty observing and modeling cold land processes.Rodell, M., H.K. Beaudoing, T. L’Ecuyer, W. Olson, J.S. Famiglietti, P.R. Houser, R. Adler, M. Bosilovich, C.A. Clayson, D. Chambers, E. Clark, E. Fetzer, X. Gao, G. Gu, K. Hilburn, G. Huffman, D.P. Lettenmaier, W.T. Liu, F.R. Robertson, C.A. Schlosser, J. Sheffield, and E.F. Wood, 2015: The observed state of the water cycle in the early 21st century, J. Climate, in press, doi:10.1175/JCLI-D-14-00555.1.

The State of the Global Water and Energy Cycles


• NASA collects and archives a huge quantity of satellite observational datasets relevant to the water cycle:

Precipitation (TRMM, GPM) Soil moisture (SMAP) Terrestrial water storage changes (GRACE, GRACE-FO) Snow cover (MODIS, VIIRS) River stage (SWOT in 2020) etc.

• NASA also supports data integration research: NLDAS, GLDAS, FEWS-LDAS, etc.MERRA NEWS

• The 2017 Decadal Survey in Earth Science will likely prioritize NASA’s water cycle mission launches for the next ten years

An important area of discussion for this conference

Discussion

nasa activities and plans in water cycle...

Documents