Giovanni Facilitates Investigations of Coastal ... - GES DISC by chenmeixiu


Giovanni Facilitates                   Geotools
Investigations of                      „07

Coastal Environmental
Processes with NASA
Remote-Sensing Data
James G. Acker
NASA Goddard Earth Sciences
Data and Information Services Center
Giovanni -generated anomaly analysis of
SeaWiFS normalized-water leaving radiance
at 555 nm for September 1999

                                nLw(555) anomaly
                                is based on the
                                compiled from
                                September 1997 to
                                August 2006
Giovanni -generated image of Tropical Rainfall
Measuring Mission (TRMM) accumulated rainfall
            from Hurricane Floyd,
           September 16-17, 1999
So now I hope that you can‟t wait to find out…

What is Giovanni ?          “Giovanni” stands for
                            GES DISC

It‟s much easier to just say “Giovanni”.
What does Giovanni do?

Giovanni is a Web-based data exploration system
that enables rapid data access, analysis, and
visualization online – users do not have to
download data files to their own system before
initiating analysis and research.
The main components of the Giovanni
interface are:

   interactive map for region-of-interest selection;
   menu of available data products;
   calendar menu for time-period selection;
   menu of visualization options;
   visualization-specific options (color palette, axis values);
   menu of output options (plot, ASCII text data)
This presentation will discuss:

 Precipitation data from TRMM;

 MODIS atmospheric data

 Atmospheric data from the Advanced Infrared
     Sounder (AIRS)

 Ocean color data from SeaWiFS and MODIS
     + sea surface temperature from MODIS
     (my specialty)
Precipitation data from the Tropical Rainfall
Measuring Mission (TRMM)

 TRMM is still in operation;

 Mission data record begins in January 1998 (other
precipitation data sets in Giovanni begin in 1979 and
1950, respectively);

 TRMM observational coverage is about 35˚ N to 35˚ S.
TRMM accumulated rainfall for Ivan, Katrina, and Rita

                                        Ivan, 09/16/2004

Katrina, 08/24 – 09/03/2005   Rita, 09/20 – 09/27, 2005
TRMM data is not just for hurricanes:

Standard convective summer thunderstorm
precipitation can also be analyzed.

                                          over Florida,
                                          August 25-31,
Atmospheric data from
the Moderate Resolution Imaging Spectroradiometer

 MODIS-Terra record begins March 2000;

 MODIS-Aqua record begins July 2002.

 Data include clouds, water vapor, and aerosols.

 Global observational coverage
Winter vs. Summer Aerosol Optical Depth
on the U.S. East Coast
      February 2003

                                 August 2003
Time-Series of Aerosol Optical Depth
over Cape Hatteras
Hovmöller time vs. longitude plot of Aerosol Optical Depth
over North Carolina and Virginia, August 2003 – January 2006

                                                   For this region:
Advanced Infrared Sounder (AIRS)

 provides relative humidity, water vapor, cloud,
and temperature data;
 can be plotted as atmospheric profiles
 daily or monthly data is available

                                                Relative humidity
                                                for North Carolina –
                                                southern Virginia
                                                region shown
                                                in previous slide
“Online Analysis Enhances Use of NASA Earth Science
Data” Eos, 88(2), January 9, 2007 *

features multiple views of Saharan dust storms:

                                                          MODIS image, aerosol
                                                          optical depth plot
                                                          and Hovmöller diagram

                                       Dry dust storm      Aerosol optical depth
                                       air mass            time-series and
                                                           AIRS relative humidity

* Reprints available on request at the end of the presentation
Ocean Color (Radiometry*) data from SeaWiFS
and MODIS-Aqua
 SeaWiFS data available from September 1997 (8-day and
   monthly data products)
 MODIS-Aqua data available from June 2002
 MODIS-Terra SST data soon-to-available from mid-2000

In addition to the basic Giovanni functions, Ocean Color
Giovanni includes:
• SeaWiFS climatological anomaly analysis
• NASA Ocean Biogeochemical Model (NOBM) output
• Multi-dataset Intercomparison Interface – multiple data
       display in map plots, time-series, and scatter plots

* as requested by the International Ocean Color Coordinating Group
Examples of coastal zone data analyses
     from Ocean Color Giovanni

       Gulf of Mexico, January 2003:
       SeaWiFS Chlorophyll color map
       MODIS-Aqua SST contour map
Animation: Southeastern United States coast,
March 30 – April 30, 2003 (with customized color palette)

       0.1 to 5.0 mg m-3
       Time-Series Analysis:
       ASCII data output from Giovanni, input to Excel spreadsheet,
       allows simple statistical analysis of time-series trends

                                                       Analysis of Region 8

                                                                    Region plot:
                                                                    averaged over
                                                                    full time-period

“Raw” time-                       Time-series
series plot:                      Analysis:
Complete                          With trend
time-period                       slope and
of area average                   significance value
      Scatter plots:
      Changes in chlorophyll-SST relationships at the mouth of Tampa Bay
      for August-November periods with high (2004, 2005)
      and low (2002, 2003) hurricane influence

Area plots of
chlorophyll                                                          Aug-Sep
for this region
and time period
in 2002 and                        2002
2005                                                            2003
                                          Nov                           Nov

                                          Aug                              Aug

                                          Sep                              Sep


                                  2004                           2005
                                          Nov                              Nov
      SeaWiFS Chlorophyll Climatological Anomaly Analysis:

      Using a September 1997 – August 2006 base period, Giovanni
      allows comparison of average chlorophyll concentrations for
      any time-period (up to one year) to the climatological average

October 2005 was the
wettest October in
history for the
northern Mid-Atlantic
and New England
coastal states
                              November 2005

Time-series of chlorophyll
concentration anomaly shows
a remarkably large anomaly
in November 2005

  Comparison of the
  chlorophyll concentration
  anomalies in November
  2004 (left) and 2005
  (right) shows the wide
  area distribution of the
  positive anomalies
These examples of Giovanni analyses provide a cross-section of
Giovanni‟s capabilities for coastal zone monitoring and research
utilizing several different remotely-sensed data products from

Coastal zone issues to which these data may be applied include:

   Water-quality monitoring
   Nutrient load impacts
   Hazardous algal blooms
   Flood and drought assessment
   Severe storm impact
   Influences on coastal habitats and protected areas
   Regional trend detection
   Air quality monitoring and event detection
For ocean color                                   We are hoping to add a
Giovanni, we are                                  euphotic depth data product
currently working on                              (1% light level), which can
the addition of a                                 be easily transformed to
“colored dissolved and                            Secchi depth values. We
detrital matter” data                             believe this product will have
product and a                                     broad applicability for coastal
particulate backscatter                           zone water quality
data product.                                     monitoring.

  Suspended sediments in Florida Bay caused by Hurricane Wilma
The coastal zone is a fragile and delicate environment. Let us all
work together to understand and protect it.

                              Thank you for your attention today.

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