Exploring Oceanographic Data in the Classroom Using the Laboratory for Ocean Color Users

Access Data from the Laboratory for Ocean Color Users Homepage

The Dataset

Data from NASA's Laboratory for Ocean Color Users is intended to provide a guided pathway to aid in the utilization of ocean color data for oceanographic and environmental research. Ocean color data provides an expression of biological activity in the oceans. Other related data parameters such as sea surface temperature are also available. LOCUS presents data using the web-based Giovanni analysis and visualization system, which enables rapid and basic statistical analyses, data sub-setting, and graphics output. The Ocean Color Web (Web site of the Ocean Biology Processing Group) provides more information and access to the complete suite of NASA ocean color data products.

Use and Relevance

Averaged global chlorophyll concentration for the month of July (from 1978 to present). From LOCUS Level 1 Browser.
Scientists use ocean color data to examine biological activity in the oceans, and physical and biological interactions. LOCUS data can also be used to examine current forcing and changes in ocean current systems. The LOCUS data set examines oceanographic processes at the surface and links biological activity, such as phytoplankton blooms, with physical properties of the ocean surface including SST and circulation patterns. Data analyses using LOCUS and Giovanni allow scientists to examine diverse research problems including:

Use in Teaching

Average chlorophyll concentration for the month of April, 2006 in the coastal regions of Florida. Generated using Giovanni.

This data can be used to teach the following concepts and skills in physical and biological oceanography:

Topics

Skills

Exploring the Data

Data Type and Presentation

Processed data for ocean color including SST, chlorophyll, and quasi-true color images is archived and can be accessed through LOCUS data products for a period ranging from 1978 to present. SST images are false-colored to represent temperature ranges from -2°C (purple) to 34°C (red). Chlorophyll images are false-colored to represent concentrations from .01 mg/m3 (purple) to 60 mg/m3 (red). Images are available for the SeaWiFS color bars representing SST and chlorophyll concentration.

Accessing the Data

SST, chlorophyll data, and quasi-true images can be obtained directly from the LOCUS website. Users can choose which subsets of data to examine. The Level 1A and 2 Browser allows users to parse data based on geographic location and data origin from satellites, including MODIS and SeaWiFS.

Manipulating Data and Creating Visualizations

Ocean color data can also be visualized using the online tool Giovanni ( This site may be offline. ) (GES-DISC Interactive On-line Visualization and ANalysis Infrastructure). Users can browse SeaWiFS and MODIS satellite data through a JAVA interface and generate GIF images or ASCII output files providing SST and chlorophyll data from September 1997 to present. Data can be accessed as time-averaged, area averaged, as an animation spanning a selected time period, or as Hovmoller plots (which plot either latitude or longitude versus time).

Tools for Data Manipulation

Giovanni ( This site may be offline. ) can be used to generate images and animations showing SeaWiFS ocean color data and MODIS ocean color and SST data. The LOCUS homepage contains six educational modules and six tutorials that describe step by step use of Giovanni. A guide to using Giovanni is also available in a PowerPoint presentation, Giovanni and LOCUS: Innovative Ways for Teachers and Students to Conduct Online Learning and Research with Oceanographic Remote Sensing Data, presented by James Acker at a meeting of the National Marine Educator's Association.

About the Data

Collection Methods

Remote sensing via satellites is used to collect data on chlorophyll concentrations in the oceans and SST. Informational links are provided explaining how data from MODIS-Aqua and SeaWiFS are processed using algorithms to determine SST data and chlorophyll concentration. Detailed information on the MODIS and SeaWiFS (more info) satellites is available from NASA and through the Scientific Documentation section of LOCUS.

Limitations and Sources of Error

Several factors including sensing in coastal regions, aerosols in the atmosphere, and phytoplankton blooms can introduce sources of error in how remote sensing data is interpreted.

References and Resources

Scientific References that Use this Dataset

Education Resources that Use this Dataset

Other Related Scientific References

Other related Education Resources

Related Links