If a divergence file is needed to be read it is best to use the file computing/readfile.pro This file will unzip the file and parse through all the elements in the file for you. A divergence file (before it is gridded) is stored in the following way: ydimension xdimension latitudes new line longitudes new line divergences new line times ydimension - varies from file to file and is the number of swath tracks in the file. xdimension - always equal to 48 - each file will contain ydimension * xdimension number of points - latitudes, longitudes, and divergences are all arrays with dimensions [ydimension, xdimension]. These arrays are needed because this dataset is not gridded. A divergence at point divergences[0, 0] is located at latitudes[0, 0] and longitudes[0, 0]. Each array is stored swath track per line (1 swath track is equal to one row of an array, ex. latitudes[0, *]). Each element is stored with a format of 10.3f - times are only stored per swath track, not per point. This creates ydimension number of times. All the times are stored on 1 line and each times element covers 8 character spaces.