# Presentation: 418146

## Giovanni and LOCUS:   Innovative Ways for Teachers and Students to Conduct

- Online Learning and Research with Oceanographic Remote Sensing Data

- James G. Acker
- NASA Goddard Space Flight Center
- Earth Sciences Data and Information Services Center
- (GES DISC)
- Code 610.2
- Greenbelt, MD 20771
*jim.acker@gsfc.nasa.gov*

*National Marine Educators Association Annual Meeting 2006*
*New York City*
*July 17, 2006*

## Goals for this demonstration:

- To provide several examples of how the GES DISC Interactive Online Visualization AN aNalysis Infrastructure (Giovanni) can be used to investigate oceanographic phenomena
- To introduce the Laboratory for Ocean Color Users (LOCUS)

## What is Giovanni ??

- 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

- Ocean Color Giovanni contains data from the
- SeaWiFS and MODIS-Aqua missions;   other
- “instances” of Giovanni have data from other
- satellite missions, and supplemental data sets

##   SeaWiFS – the Sea-viewing Wide Field-of-view Sensor, and MODIS-Aqua, the Moderate Resolution

-   SeaWiFS – the Sea-viewing Wide Field-of-view Sensor, and MODIS-Aqua, the Moderate Resolution
- Imaging Spectroradiometer on the Aqua satellite,
- provide ocean color data to Giovanni.  The primary data of interest is chlorophyll *a* concentration
- (chl *a*), though additional data products are available.
-  MODIS-Aqua also provides sea surface temperature (SST) data.
-  This demonstration will utilize chl *a* and SST data.

## 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

## URL for Ocean Color Giovanni:

- _[http://reason.gsfc.nasa.gov/Giovanni/](http://reason.gsfc.nasa.gov/Giovanni/)_
- (This instance of Giovanni was funded partly by a NASA REASoN CAN project, the Ocean Color Time-Series Project)

**Entry Page**:

- _MODIS-Aqua Monthly products_

- _SeaWiFS Monthly products_

- _SeaWiFS 8-day products (new!) _

- _SeaWiFS and MODIS-Aqua_
- _Multi-parameter Inter-_
- _Comparison (Monthly)_

## Demonstration Project 1:    Peru Upwelling Zone

- Goal:   Visualize chlorophyll concentrations in a
- selected region-of-interest

- Select region-
- of-interest with
- click-and-drag

- Select parameter:
- Chlorophyll *a*
- concentration
- is the default
- selection

- Lat-lon
- values may
- be entered
- instead of
- click-and-
- drag

- _Data Types:_
- Parameter
- Animation
- Climatology

## Visualization and Plotting Options

- _Plot types:   Lat-Lon map;  Animation;  Time-Series;  Hovmöller plots _

- Time period
- selection

- Color
- palette
- options

- Steps:   1.   Keep all default options
- 	2.   Select any time period in mission range
- 		(Example:  January 2001 to December 2001)
- 	3.   Click “Generate plot”

- Y-axis
- plotting options

- Output options:
- Numeric (ASCII)
- data can be
- chosen

- Data files with
- increased spatial
- resolution can
- be ordered

## Peru Upwelling Zone, January-December 2001

- Output:

- Image is the average of all chlorophyll concentration values for the entire 2001 year.  The image provides lat/lon information and a color bar scale.  It can be downloaded immediately.

## Demonstration Project 2:   Arabian Sea Monsoon

- Goals:
-  Create an animation of the Arabian Sea monsoon
-     with SeaWiFS 8-day data;
-  Create a time-series of chl *a* in the Arabian Sea

- Steps:
- 1.  “Back” to entry page
- Choose SeaWiFS 8-day data
- 3.   Select the region
- Select Animation
- Select a year
- Click “Generate Plot”

**Region**

**Animation**

**Year**

## Animation output:   selected frame

- Images can be stepped through (+1, -1) or whole animation can be
- viewed

## Arabian Sea Monsoon:   Time-Series

- Choose a smaller area within the Arabian Sea (try the “Zoom In” button)
- Select “Time Series” under
- 	_Plot Type_
- Click “Generate
- 	Plot”
- 	(I chose an area off the coast of Somalia to generate the demonstration plot)

## Arabian Sea Monsoon:   Time-Series Output

- _Note that values in this time period may be suspect due to cloud cover_

- The Y-axis can
- be “customized”
- to emphasize
- features in the data,
- or to make several
- plots with the same
- axis range, to enable
- comparisons.
- The default option,
- a “dynamic” Y-axis,
- is based on the
- range of values
- in the data.

## Demonstration Project 3:   Central America 

- (Wind-driven productivity and El Niño anomalies)

- Choose the Region
- Select _February_
- 	_2000_
- Generate the
- 	Lat/Lon map
- Change “Data
- 	Type” to Anomaly
- Change the month
- 	to _February 1998_
- Generate the
- 	Lat/Lon map
- Choose a region
- 	inside a jet
- Change “Data Type”
- 	to “Time-Lon
- 	Hovmöller,
- 	Lat-Averaged”
- 9.    Choose _Oct 97-Dec 2000_
- 10.  Generate the plot

**Goal:    Create chl *****a***** anomaly plots and Hovmöller plots**

- First:   “Back” to entry page;  select SeaWiFS _Monthly_ data.  Then:

## Demonstration Project 3:   Central America  (Wind-driven productivity and El Niño anomalies)  Output 

- Productivity driven by gap winds dominates
- this region during normal winter months

- During the 1997-1998 El Niño, productivity
- was markedly suppressed due to increased
- thermocline depth (negative anomalies are
- blue and purple)

- The Hovmöller plot demonstrates the
- seasonality of the phenomenon and the
- effect of the 1997-1998 El Niño

- Jets

## Demonstration Project 4:    North Atlantic Bloom

- (Multi-parameter intercomparison Part 1)

- The next two
- demonstrations
- utilize the Multi-
- Parameter
- Intercomparison
- System

**Goal:  Create **
**a two-parameter**
**time plot**

## Demonstration Project 4:    North Atlantic Bloom

- (Multi-parameter intercomparison Part 1)

- Region

- For the time period,
- select a full year of
- data.  MODIS-Aqua
- data begin in 2002;
- _try Jan-Dec 2003._

- Select “**Time plot of**
**area-averaged **
**parameters**”

- Select SeaWiFS chl *a*
- and MODIS-Aqua
- SST

## Demonstration Project 4:    North Atlantic Bloom

- (Multi-parameter intercomparison Part 1) Output

- Students may think that the North Atlantic Bloom is related to warmer
- ocean temperatures;   a plot like this may force modification of that idea

## Demonstration Project 5:    Benguela Upwelling Zone

- (Chl *a* vs. SST scatter plots)

**Goal:  Create a **
**Chl *****a***** vs. SST**
**scatter plot**

- Region

- Plot type:  select
- “Scatter plot of
- parameters in selected
- area and time period”
- (Area plot is also
- interesting)

- Select
- SeaWiFS chl *a*
- and Aqua SST

## Demonstration Project 5:    Benguela Upwelling Zone

- (Chl *a* vs. SST scatter plots)  Output

- The chl *a* vs. SST scatter plot shows that
- lower SST is associated with higher
- chl *a *in the upwelling zone

- The area plot of chl *a* (color)
- and SST (contour lines) shows
- the colder temperatures
- are near the coast, as are the
- higher chl *a *values

## The Laboratory for Ocean Color Users (LOCUS)

- The URL for the Laboratory for Ocean Color Users:
- _http://disc.gsfc.nasa.gov/oceancolor/locus/index.shtml_

- LOCUS currently features
-  recent articles;
-  Educational Modules illustrating basic concepts;  and
-  Tutorials combining research and data aspects.

- LOCUS needs:
-   more research projects!
- LOCUS is ready to become collaborative at several levels
- of expertise – experts can be consulted to assist with
- research projects.    We need “researchers” – especially
- educators and students – to ask questions and provide
- research project examples.

## Any questions?

- demonstration!