# Presentation: 287394

## Summary

- James Acker1, Greg Leptoukh1, Steve Kempler1, Watson Gregg2, Steve Berrick1,
- Tong Zhu1, Zhong Liu1, Hualan Rui1, Suhung Shen1
- 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  USA
- 2 GSFC Laboratory for Hydrospheric Processes, Code 970
_**http://daac.gsfc.nasa.gov/**_
***FOR MORE INFORMATION:  acker@daac.gsfc.nasa.gov***
- The Ocean Color Time-Series Project, including Giovanni development,
- is supported by NASA through REASoN CAN 42-OES-01.

- 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 and Moderate Resolution Imaging Spectroradiometer (MODIS-Aqua). The first phase of this project includes tutorials demonstrating the use of Giovanni and collaborative assistance in the development of research projects using SeaWiFS, MODIS-Aqua, and Ocean Color Time-Series Project data in the online Laboratory for Ocean Color Users (LOCUS).
- 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.**   **

**FOCUS ON RESULTS**

**ADD VALUE TO RESULTS**

**USE GIOVANNI FOR FURTHER ANALYSIS**

**PUBLISH**

**BRING 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**

**Summary**

**GES DISC: THE BRIDGE BETWEEN DATA AND SCIENCE**

- 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 facilitates the use of these data products by providing data analysis capabilities without the necessity for ordering and acquiring large data volumes 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.
- Giovanni’s initial implementation 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) and 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).
- Giovanni users select geophysical parameters and the geographical region and time period of interest. The system rapidly generates 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 Web site provides access to Giovanni, explanation of the goals of the project, progress reports, and other relevant information.    The Web site hosts the Laboratory for Ocean Color USers (LOCUS), which provides (or will provide in the future):  demonstrations of Giovanni applications; guidance and assistance for research investigations and projects;  and examples of ocean color research efforts which have utilized Giovanni and the time-series data products.
- The first activity within LOCUS was the creation of three research tutorials.  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.

**Laboratory for Ocean Color Users (LOCUS) Tutorials:  Intriguing Observations**

**Influence 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 differences on the Pacific and Caribbean sides of the Isthmus of Panama cause high 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 chlorophyll concentrations.
- 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 anomalously higher chlorophyll concentrations in autumn 2001, preceding the occurrence of a moderate El Niño in 2002-2003.   Further investigation is 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.   SeaWiFS ocean 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 seasonal pattern 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 maps and 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 chlorophyll concentrations are due to wind transport of chlorophyll-rich detritus from  this reef.

**Wind-mixing events during winter enhance phytoplankton productivity in the Gulf of Panama.**

**Average chlorophyll concentrations over the SeaWiFS mission period show the characteristic seasonal pattern, and the influence of El Ni****ño.**

**Latitude vs. time plot displaying reduced chlorophyll during 1997-1998 El Ni****ño****, and anomalous increased productivity during autumn 2001.**

**Average chlorophyll concentrations in the Red Sea in the year 2001.**

**Latitude vs. time plot for the year 2001, showing the northern Red Sea spring bloom and an unusual ocean color feature observed in winter, spring, and autumn.**

**Annual chlorophyll**
**concentrations in 2001 on the Red Sea coast show **
**the location of the unusual feature (dynamic color scale is used here).**

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

**The REASoN for Giovanni**

- Ocean Color Data Analysis with Giovanni

- (GES DISC Interactive Online Visualization and ANalysis Infrastructure)

** ****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.

**DATA AVAILABLE**

- _This demonstration was created solely for this poster and had not been conducted previously._

**Giovanni Home Page**

_**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 high productivity 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.**

**Giovanni Session Demonstration:   Seasonal Productivity in the southeast Caribbean Sea**

- Real Data and Rapid Results: