Ocean Sciences GIS Exercise - Visualizing High Resolution Oceanographic Data Sets

Geographic Information Systems, GIS, are designed for visualization of data in spatially referenced space. In ArcMap, high resolution oceanographic data from the National Oceanographic Data Center (NODC) combined with world topography and bathymetry data allow students to visualize global patterns of ocean temperature, salinity, dissolved oxygen and others.

This exercise is designed to introduce students to ArcGIS software components ArcCatalog, ArcMap and ArcScene using the software to visualize and manipulate actual oceanographic data. The exercise is designed to build the students' familiarity with the software within the context of an Ocean Sciences course.

Students preview data sets in ArcCatalog and read a brief discussion of the different types of data used in the exercise (raster and shape files). In ArcMap, students add a global topography and bathymetry file, and examine the fact that these data are spatially referenced. Students then add a point shape file of over 41,000 sample locations from the World Ocean Atlas Select data set. A look at the attribute table reveals no obvious patterns and, as all the points are initially symbolized identically, no pattern is obvious on the map either. Zooming in on a small area reveals the individual points, and using the Get Info tool reveals the associated metadata for the point. Using the symbology tools, students can modify the temperature point file properties to reveal a pattern of warm equatorial and cold polar surface water distribution.

Building on this, students extract data for individual depths and create maps of temperature distribution at various depths. To make the changes that occur at depth more obvious, students use ArcScene to display layers from multiple depths in 3D. Warm and cold water distribution associated with deep ocean current systems are revealed.

This exercise could also use any of the other data sets from NODC WOAS.