include file: SWRAYSCA 3
      REAL RAYSCA,                     ! Fraction of incoming sunlight     SWRAYSCA.2      
C     ! assumed to be Rayleigh-scattered back to space immediately.        SWRAYSCA.3      
     &     ONELRS                      ! 1-RAYSCA                          SWRAYSCA.4      
      PARAMETER ( RAYSCA = .03, ONELRS = 1. - RAYSCA )                     SWRAYSCA.5