Selection Functions in Giovanni
4.1 Data Set Selection
Giovanni currently provides analytical capabilities for ocean color data products from two remote-sensing missions, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission and the Moderate Resolution Imaging Spectroradiometer (MODIS) mission on the Aqua satellite (MODIS-Aqua). Designation of the data set is accomplished through the page below. The Java Version option allows utilization of the Java map for regional area selection. The Non-Java Version option requires input of latitude and longitude boundary coordinates for regional area selection. The example below would select "SeaWiFS Monthly Global 9-km Products", where "9-km" indicates the spatial resolution of the data set and "Monthly" indicates the temporal resolution of the data set.
4.2 Area Selection
Area selection in the Java version is accomplished by click-and-drag manipulation of the box appearing on the Java map. In the example below, an area covering most of the North Atlantic Ocean has been selected. Note that the latitude and longitude coordinates for the area will appear to the right of the map as the size is adjusted. (The selected area below will be used to illustrate the Area Plot output option in the next section of the manual.)
4.3 Time Selection
Time period selection is performed using the "Begin Year", "End Year" "Begin Month" and "End Month" buttons and selecting from the drop-down menus. In the example below, the Begin Year is 2004, the End Year is 2004, the Begin Month is January, and the End Month is December, so the period January-December 2004 has been selected.
4.4 Parameter Selection
Parameter selection is performed using the "Parameters" menu. In the example below, "Chlorophyll a concentration" has been selected. (These selections and the designated area will be used to illustrate the Time Plot output option in the next section of the manual.)
4.5 Data Type Selection
SeaWiFS ocean color data offers three data type selections (listed below). MODIS-Aqua data only offers data parameters, so this is not an option for MODIS-Aqua data.
plots the selected parameter of interest.
plots the positive or negative anomaly compared to the climatological mean values
plots the climatological mean values for time periods between one month and one year.