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James Acker2, Greg Leptoukh1, Steve Kempler1, Watson Gregg3, Steve Berrick1,

Tong Zhu2, Zhong Liu2, Hualan Rui2, Suhung Shen4

1 NASA Goddard Earth Sciences (GES) Data & Information Services Center (DISC) / Distributed Active Archive Center (DAAC)

Code 902, NASA Goddard Space Flight Center Greenbelt, Maryland 20771 USA2 Science Systems and Applications, Inc.3 GSFC Laboratory for Hydrospheric Processes, Code 9704 George Mason University

http://daac.gsfc.nasa.gov/

FOR MORE INFORMATION: acker@daac.gsfc.nasa.gov

The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) has taken a major step addressing the challenge of using archived Earth Observing System (EOS) data for regional or global studies by developing an infrastructure with a World Wide Web interface which allows online, interactive, data analysis: the GES DISC Interactive Online Visualization and ANalysis Infrastructure, or "Giovanni." Giovanni provides a data analysis environment that is largely independent of underlying data file format.

The Ocean Color Time-Series Project has created an initial implementation of Giovanni using monthly Standard Mapped Image (SMI) data products from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission. Giovanni users select geophysical parameters, and the geographical region and time period of interest. The system rapidly generates a graphical or ASCII numerical data output. Currently available output options are: Area plot (averaged or accumulated over any available data period for any rectangular area); Time plot (time series averaged over any rectangular area); Hovmöller plots (image view of any longitude-time and latitude-time cross sections); ASCII output for all plot types; and area plot animations. Future plans include correlation plots, output formats compatible with Geographical Information Systems (GIS), and higher temporal resolution data.

The Ocean Color Time-Series Project will produce sensor-independent ocean color data beginning with the Coastal Zone Color Scanner (CZCS) mission and extending through SeaWiFS and Moderate Resolution Imaging Spectroradiometer (MODIS) data sets, and will enable incorporation of Visible/Infrared Imaging Radiometer Suite (VIIRS) data, which will be added to Giovanni. The first phase of Giovanni will also include tutorials demonstrating the use of Giovanni and collaborative assistance in the development of research projects using the SeaWiFS and Ocean Color Time-Series Project data in the online Laboratory for Ocean Color Users (LOCUS).

The synergy of Giovanni with high-quality ocean color data provides users with the ability to investigate a variety of important oceanic phenomena, such as coastal primary productivity related to pelagic fisheries, seasonal patterns and interannual variability, interdependence of atmospheric dust aerosols and harmful algal blooms, and the potential effects of climate change on oceanic productivity.

• SeaWiFS: monthly global 9-km product• MODIS-Aqua: monthly global 9-km product SeaWiFS SMI products: chlorophyll a concentration, K(490), nLw(555), Angstrom coefficient 510-865nm, τ(865). MODIS products use closest equivalent wavelength.

FOCUS ON RESULTS ADD VALUE TO RESULTS USE GIOVANNI FOR FURTHER ANALYSIS PUBLISHBRING THE EARTH INTO FOCUS

Remote sensing data and data products at no cost

Modular algorithm integration for high-volume processing

Complex data interpretations and statistical analyses

Focus on analysis without having to download data

ABSTRACT

GES DISC: THE BRIDGE BETWEEN DATA AND SCIENCE

DATA AVAILABLE

Real Data and Rapid Results:

Ocean Color Data Analysis with Giovanni (GES DISC Online Visualization and ANalysis Infrastructure)

Giovanni Session Demonstration: Seasonal Productivity in the southeast Caribbean SeaThe REASoN for Giovanni

The Goddard Earth Sciences Data and Information Services Center (GES DISC) created Giovanni – the GES DISC Interactive Online Visualization and ANalysis Infrastructure – as a prototype data analysis tool for the multi-decadal ocean color time-series products that are currently being created by the Ocean Color Time-Series Project, a Research, Education, and Applications Solution Network (REASoN) project. Giovanni is intended to facilitate the use of these data products by providing data analysis capabilities without the necessity for ordering and acquiring large volumes of data or extensive sets of data files. Tools like Giovanni alter the role of a data archive from that of a data provider to a more interactive role as an intermediary in the research use of data products contained in the archive.

In its initial implementation, Giovanni uses Level 3 Standard Mapped Image (SMI) products from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission and Moderate Resolution Imaging Spectroradiometer (MODIS) Level 3 SMI products created by the Ocean Color Data Processing System (OCDPS) for MODIS-Aqua data. The Ocean Color Time-Series Project will create a multi-decade ocean color time-series with the addition of data from the Coastal Zone Color Scanner (CZCS), the Ocean Color and Temperature Scanner (OCTS) to the SeaWiFS and MODIS data sets, and will create a framework allowing the eventual addition of other ocean color data sets, such as new data from the Visible/Infrared Imaging Radiometer Suite (VIIRS).

The Ocean Color Time-Series Web site provides access to Giovanni, explanation of the goals of the project, progress reports, and other relevant information. The Web site also hosts the Laboratory for Ocean Color USers (LOCUS), which provides (or will provide in the future): demonstrations of Giovanni applications; guidance in research and investigation using ocean color data, ocean color time-series data products, and Giovanni; and examples of ocean color research projects which have utilized Giovanni and the time-series data products.

The first activity within LOCUS was the creation of three research tutorials demonstrating how Giovanni can be used for research projects. These tutorials examined familiar settings in which the underlying biological dynamics were relatively well-known. However, in the course of creating the tutorials, Giovanni allowed the observation of unexpected features in the data, showing that Giovanni enables open-ended discovery-based research. Because the use of Giovanni is highly intuitive and remarkably simple, Giovanni enables scientific investigation and instruction at the “entry level”: undergraduates and even high school students.

Giovanni enhancements planned for the near-future will make it even more useful to a broad spectrum of the oceanographic research community. These enhancements include: correlation plots; error analysis capability; output formats compatible with Geographical Information Systems (GIS); more image format options; and higher temporal resolution data.

This demonstration was created solely for this poster and had not been conducted previously.

Giovanni Home PageSelection of research areaof interest. Java map or entryof geographical coordinates areoptions.

Chlorophyll a area plot for 2002. Thedefault color scale was selected; dynamic and user-specified color paletterange can also be selected.

Time plot of chlorophyll a concentrationfor the SE Caribbean Sea in year 2002.This area is significantly influenced bythe “rainy season” outflow from the Orinoco River. Higher freshwater flow from the Orinoco provides increased nutrients, increasing phytoplankton productivity, which is observed as higherchlorophyll concentration.

Area plot of chlorophyll a concentrations during the low productivity phase, February 2002. Higher chlorophyll concentrations are observed in the coastal region of Venezuela, and significantly lower concentrations in the Caribbean Sea, especially around the Lesser Antilles.

Area plot of chlorophyll a concentrationsduring the highproductivity phase, July 2002. The influence of nutrients in the Orinoco River outflow is clearly seen in this monthly area plot. Also note in the southeastern corner of the region another area of increased productivity, likely due to increased freshwater flow from the Amazon River.

Hövmoller latitude vs. time plot for the southeast Caribbean Sea in year 2002. This plot shows the extent of influence from the rainy season Orinoco River freshwater flow, with significantly increased chlorophyll concentrations extending to 15º N and slightly elevated concentrations extending to 17º N.

The total time required to generate these images and plots wasless than 15 minutes.

Laboratory for Ocean Color Users (LOCUS) Tutorials: Intriguing ObservationsInfluence of El Niño on the Gulf of Panama Seasonal Productivity Cycle

The biological dynamics of the Gulf of Panama are dominated by winter wind-mixing events. Atmospheric pressure differenceson the Pacific and Caribbean sides of the Isthmus of Panama causehigh wind speed events through the Gaillard Cut (Panama Canal Zone). These winds mix nutrients from deeper waters to the surface,resulting in increased phytoplankton productivity and higher chlorophyllconcentrations.

This tutorial investigated the influence of El Niño/La Niña events on the phytoplankton productivity of the Gulf of Panama. The expected suppression of productivity during the strong 1997-1998 El Niño was observed. The tutorial also observed anomalouslyhigher chlorophyll concentrations in autumn 2001, preceding the occurrence of a moderate El Niño in 2002-2003. Further investigationis required to determine if this observation is an El Niño precursor.

Seasonal Patterns and Mysteries in the Red Sea The Red Sea is one of the lowest-productivity bodies of water in

the world, due primarily to low nutrient concentrations. No major rivers enter the Red Sea. The clarity and warmth of the Red Sea waters, and its remoteness, make it home to many of the world’s most pristine coral reefs.

This tutorial investigated seasonal cycles in the Red Sea. SeaWiFSocean color data indicated that the northern Red Sea has a brief “spring bloom” pattern, with slightly elevated chlorophyll concentrations that are still quite low. The southern Red Sea has a distinctly different seasonalpattern that is linked to the Arabian Sea monsoon.

Giovanni data analysis in the northern Red Sea indicated a small,mysterious feature of elevated chlorophyll concentrations in the winter, spring, and fall, which was absent in the summer. Examination of mapsand descriptions of this area indicated that the feature was in the location of the large Mirear Island reef complex. The seasonality of the elevated chlorophyll concentrations supports a hypothesis that the higher chlorophyllconcentrations are due to wind transport of chlorophyll-rich detritus from this reef.

Wind-mixing events during winter enhancephytoplankton productivity in the Gulf of Panama.

Average chlorophyll concentrations over theSeaWiFS mission period show characteristicseasonal pattern and influence of El Niño.

Latitude vs. time plot displaying reduced chlorophyllduring 1997-1998 El Nino, and anomalous increased productivity during autumn 2001

Average chlorophyll concentrationsin the Red Sea in the year 2001.

Latitude vs. time plot for the year 2001, showing thenorthern Red Sea spring bloom and an unusual oceancolor feature observed in winter, spring, and autumn.

Annual chlorophyll concentrationsin 2001 on the Red Sea coast show the location of the unusual feature(dynamic color scale used).

Landsat image of the Mirear Island reef complex (obtained from the Millenium CoralReef Project image library). Higher chlorophyll concentrations shown in the figure at left occur offshore of this reef complex.