CALL SEQUENCE...
       gghems  GGL GGN GGS OUTPUT
 
 
      AUTHOR  - J.D.Henderson, DEC 17/80.
      LAST REVISION: $Header: Autres-corrections-d-usages-de-MAXW-NWDS-modifs-dans-GGSIGN-SIGNAG @ 2018-06-05 17:00:06 -0400 (dugas) $
 
 
      PURPOSE - SPLITS A FILE OF GLOBAL GRIDS OR CROSS-SECTIONS
                INTO TWO FILES OF NORTHERN AND SOUTHERN HEMISPHERES.
 
      NOTE    - IF THE FILE IS ALREADY HEMISPHERIC, IT IS ONLY COPIED TO
                THE CORRESPONDING HEMISPHERIC FILE.
 
 
      INPUT FILE...
       GGL = GLOBAL GRIDS OR CROSS-SECTIONS
             (GLOBAL GAUSSIAN ARRAYS MUST HAVE AN EVEN NUMBER OF LATITUDES)
 
      OUTPUT FILES...
       GGN = NORTHERN HEMISPHERE GRIDS OR CROSS-SECTIONS
       GGS = SOUTHERN HEMISPHERE GRIDS OR CROSS-SECTIONS
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
        1 ABORT ERROR READING GGL
        2 MORE THAN ONE SIZE IN GGL
        3 UNKNOWN HEMISPHERIC TYPE
        4 UNEVEN NUMBER OF LATITUDES IN GLOBAL GAUSSIAN ARRAY