If you want to plot or analyze climatological data, this is where to start. Extract Data will allow you to select a category and timeframe of climatological data. Digital Atmosphere will then create a custom data field, saving it into CUSTOM.DAT in your Digital Atmosphere directory. This can then be immediately plotted (with Graphics, Plot, Custom Data) or analyzed (with Analyze, Custom Data Field). You can even import the data into a spreadsheet or database program.