Exploiting the Capabilities of NASA's Giovanni System

for Oceanographic Education

James AckerNASA Goddard Earth Sciences Data and Information Services Center (GES DISC)NASA Goddard Space Flight CenterGreenbelt, MD

Presented at the 2007 EARSeL Symposium, Bolzano, ItalyJune 6th, 2007

Co-authors:Cmdr. Emil Petruncio, United States Naval AcademyGregory Leptoukh, GES DISCSuhung Shen, GES DISC/George Mason University

Goals of this presentation:

Discuss the goals of oceanographic education Describe the Giovanni system Demonstrate Giovanni output types Document Giovanni usage in oceanography classes Determine effective usage methods Devise educational implementation strategies

Discuss the goals of oceanographic education

Teaching oceanography is the teaching of a field of scientific endeavour.

Teaching oceanography effectively should, therefore,incorporate instructional elements, research elements, and historical discoveries.

Effective teaching should enhance students’ knowledge of the field AND how the field is advanced by research.

Discuss the goals of oceanographic education

Four basic core oceanographic sub-disciplines:(classically, and from personal experience)

Biological OceanographyPhysical OceanographyGeological OceanographyChemical Oceanography

Giovanni is utilized most effectively for exploring linkages between physical and biological oceanography

Describe the Giovanni system

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 theSeaWiFS and MODIS-Aqua missions; other “instances” of Giovanni have data from othersatellite missions, and supplemental data sets

Describe the Giovanni system

The main components of the Giovanni interfaceare:

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

Demonstrate Giovanni output types

Area plot

Animations display successivearea plots

Time -series

Hövmoller plots

ASCII text output currentlyavailable; next-generationGiovanni will provide ASCIIand HDF file output

Demonstrate Giovanni output types: Examples of visualization-specific options

Pre-defined color palette

Customized color palette

Y-axis customization

Demonstrate Giovanni output types

The Multi-Dataset Intercomparison Interface available in Ocean Color Giovanni (similar capabilities are being developed for other Giovanni interfaces) provides additional output typesMultiple data productarea plot:

Sea surfacetemperature (contours) andchlorophyllconcentration(color scale)

Demonstrate Giovanni output types

X-Y scatter plots(here, SST vs. chlorophyll)

Multiple data producttime-series(here, SST vs. chlorophyll,in a Giovanni output figureadapted for publication)

Demonstrate Giovanni output types

Ocean Color Giovanni currently provides these oceanographic data products for visualization and analysis:

Chlorophyll concentration Diffuse attenuation coefficient at 490 nm Normalized water-leaving radiance at 555 nm (SeaWiFS)or 551 nm (MODIS) Absorption coefficient of dissolved and detrital matter at 443 nm Particulate backscatter coefficient at 443 nm Sea surface temperature (MODIS) Assimilated chlorophyll and other output fields from the NASA Ocean Biogeochemical Model (NOBM)

Document Giovanni usage in oceanography classes

Some initial examples:From Dr. Samantha Lavender, University of PlymouthSchool of Earth, Ocean, and Environmental Sciences:

Undergraduate research – provides students witha variety of interesting areas to investigate; will utilizeGiovanni’s time-series capability as part of theseanalyses

Document Giovanni usage in oceanography classes

From Dr. Bulusu Subrahmanyam, University of South Carolina Satellite Oceanography Laboratory,Marine Science Program in the Department of Geological Sciences

“Giovanni continues to be an exceptional tool that provides users (expert and novice alike) with a simple way to visualize and analyze remote sensing data without the inconvenience of having to download data. I and my research students will continue to use Giovanni throughout our research endeavors due to these main points.”

Document Giovanni usage in oceanography classes

Examples of educational use from the University of South Carolina Satellite Oceanography Lab

Class: Remote Sensing Lab, MSCI 312 (undergraduate):

Generate a plot of chl a for the Costa Rica Dome region

Generate time-series of chl a and SST for the equatorialIndian Ocean in the year 2005

Generate a scatter plot of chl a from SeaWiFS and MODIS-Aqua for the Gulf of Mexico region

Document Giovanni usage in oceanography classes

From Dr. Joaquim Goes, Bigelow Laboratory for OceanSciences:

“I now routinely use Giovanni for my work, and always prescribe it for remote sensing projects that are undertaken byundergraduate students who intern with us each summer. I have personally found that Giovanni has made satellite oceanography less daunting and remote sensing projectsvery enjoyable. Students can now pick and subset data without mastering programming or having to first download large satellite datasets on to their computers.”

“I believe that having teachers get a feel for this simple but powerful research tool will make remote sensing accessible even to high school students.”

Document Giovanni usage in oceanography classes

Dr. Goes described one example of a student research project devoted to the Arabian Sea monsoon – the studentused Giovanni extensively to characterize monsoonal variability, major zones of productivity, and wind-drivencoastal upwelling.

Document Giovanni usage in oceanography classes

A dedicated pedagogical example: U.S. Naval Academy, Spring Semester 2007Oceanographic Remote Sensing Class,Instructor: Cmdr. Emil Petruncio

Step 1. Students were provided with a Giovanni overview presentation. A knowledge survey consisting of questions which could be answered with Giovanni was administered prior to the presentation; subsequent to the demonstration, student expectations were solicited.

Document Giovanni usage in oceanography classes

Step 2. Students were given a collaborative research project assignment for which Giovanni was the research tool to be used.

Step 3. Students presented research results. Students were then shown how to answer the knowledge survey questions with Giovanni, and used the system to address the questions. An evaluation survey was also completed.

Document Giovanni usage in oceanography classes

Examples of student expectations:

“I would like to use it to examine upwelling patterns along an eastern boundary current, such as California… The map function is very easy to use and self-explanatory.”

“The system is about as easy as it gets with regard to first-time and returning user functionality. … Logically laid out and well-documented, Giovanni should not present any problems.”

“The program seems very useful in terms of ease of use and research.”

“I would like to use Giovanni to see how the chlorophyll concentrations change during El Nino years off the coast of Peru.”

“I believe the program is fairly easy. I’m not a very computer literate personand I found it simple.”

“I appreciate the speed at which outputs are generated.”

Document Giovanni usage in oceanography classes

Student research project: Investigate the effects of monsoonalcirculation near the Taiwan Strait and Luzon Strait

Three student groups were assigned a region to investigate;Cmdr. Petruncio investigated a fourth region as an example.

War

m, m

ois

t

Summer MonsoonMay - September

Co

ld, d

ry

Winter MonsoonNovember - March

Tropic of Cancer

West

South

East

North

Document Giovanni usage in oceanography classes

Example of results from the West Box follows

West Box: Chl a, K490, nLw551

K490 & Chl a .956692

K490 & nLw551 .720605

Correlation Coefficients

West Box: Chl a and SST

Correlation Coefficient = - 0.581812

West Box: nLw551 and SST

Correlation Coefficient = - 0.559207Correlation Coefficient = - 0.804252

Document Giovanni usage in oceanography classes

Examples of student conclusions:

• Monsoonal variability in SST observed at all four locations. Greater range in SSTs in Taiwan Strait and north of Taiwan, with much colder SSTs during winter monsoon.

• nLw551 is relatively high and negatively correlated with SST in the North and West boxes, much weaker and more variable in the East and South boxes

Document Giovanni usage in oceanography classes

More student conclusions:

• Strong correlation at all locations between K490 and Chl a.

– In Taiwan Strait, K490 is also strongly correlated with nLw551. Chl a algorithm in Taiwan Strait may be inaccurate due to presence of suspended sediments, likely advected southward from the Yellow Sea during the winter monsoon.

• West Box–Moderate negative correlation between SST & Chl a, strong negative correlation between SST & nLw 551

Document Giovanni usage in oceanography classes

Knowledge Survey: before and after(10 questions, one determined to be unanswerable with Giovanni (answerprovided)

Student 1: Before, 70%; After, 100%Student 2: Before, 60%; After, 100%Student 3: Before, 10%; After, 60%Student 4: Before, 50%; After, 100%Student 5: Before, 30%; After, 90%Student 6: Before, 30%; After, 80%

Although Giovanni was used in “guided” fashion to answer the questions, the results show an expansion of oceanographic knowledge gained through use of the system.

Document Giovanni usage in oceanography classes

Final comments, observations from the Naval Academy remote sensing class

Virtually all the students (and the instructor) wanted more oceanographic data types [sea surface height, winds, wave height, and longer data sets (!)] All students indicated using Giovanni met or exceeded expectations generated by the demonstration All students strongly agreed additional use of Giovanni wouldenhance oceanographic knowledge Some students indicated that rapid generation of visual imagesincreased understanding and pattern recognition Speed and interface simplicity were indicated as advantages

Determine effective usage methods

Question: If Giovanni is an excellent teaching resource,what is the best way to use it?

Four usage methodologies:I. Guided answering of questions. Provide a question, and show students stepwise how to utilize Giovanni to answer it.II. Unguided answering of questions. Provide a question, let students figure out how to use Giovanni to answer it.III. Guided research. Provide a research topic or area; tell students what functions to perform for analysis.IV. Unguided research. Provide a research topic or area; let students utilize Giovanni as they wish to investigate it.

Determine effective usage methods

Question: What is the most effective methodology?

• The most effective methodology is Guided Research (if time permits). Giovanni can certainly be used to answerquestions, but this does not fully demonstrate itsusefulness for research.

• Guided Research can illustrate concepts and regional oceanographic processes with the student performing theirown investigative process. This method reinforces knowledgebetter than fact acquisition, and also increases awareness of how remote-sensing research is conducted.

Determine effective usage methods

Unguided Research is also an excellent methodology forGiovanni in oceanographic education, provided that fundamental concept knowledge has already been attained.

Students can quickly and easily assemble research projects with Giovanni visualizations and analyses, following a “learning by doing” (emphasis on studentunderstanding through inquiry) scientific education model strongly advocated by the National Science Education Standards.

Devise educational implementation strategies

Question: What are the primary barriers to incorporationof Giovanni in oceanographic education?

First, application areas. Giovanni does not fit neatlyinto the core disciplines of oceanography. It ismost applicable to demonstrating how physical oceanography influences biological patterns and dynamics –an intermediate knowledge level.

Thus (though it is easy to use) -- understanding the data visualizations that Giovanni creates requires that basic oceanographic concepts have already been learned.

Devise educational implementation strategies

Second (and more importantly) is the barrier of establishedcurricula in classroom instruction.

Skilled teachers who have taught courses for many years know what works, and they cover the material they havedetermined to be necessary.

Adding something “new” like Giovanni requires replacingan instructional element that has functioned well with something as good – preferably better.

AND it should be easy for them to do that!!

Devise educational implementation strategies

Question: What is needed to facilitate Giovanniimplementation in oceanographic education?

Answer: A Giovanni “cookbook” – providing “recipes”for the investigation of a multitude of regions andoceanographic processes.

A skilled chef – the classroom instructor – can selectthe appropriate recipes which satisfy the educational requirements of a particular course.

A recipe would indicate the data products, visualizations, regions, time periods, etc. to produce the desired output – which the student interprets (Guided Research).

Devise educational implementation strategies

CONCLUSION

Giovanni has reached a level of maturity and acceptancein the scientific and educational community that the creation of a Giovanni “cookbook” is now a recognized goal.

HOWEVER, forward-thinking instructors and educators can (and will) begin to develop such recipes on their own.

OK, what’s the background image?

Thank you for your attention today.

This image shows the biological response to a “Tehuano” wind event. Strong episodic winter winds through a mountain pass in Mexico mix nutrients in deeper waters to the surface, fostering phytoplankton blooms.

Where to find Giovanni !

Giovanni: http://giovanni.gsfc.nasa.gov/

Ocean Color Giovanni:http://reason.gsfc.nasa.gov/Giovanni/

Laboratory for Ocean Color Users (LOCUS)http://disc.sci.gsfc.nasa.gov/oceancolor/locus/index.shtml