      PROGRAM DELETA
C-------------------------------------------------------
C***  FIND THE ETA VALUE ON TOP OF A LOWEST ETA LAYER
C***  OVER THE OCEAN THAT IS Z METERS THICK IN THE
C***  STANDARD ATMOSPHERE
C-------------------------------------------------------
      T0=288.
      P0=101325.
      PT=2000.
      GAM=.0065
      R=287.04
      G=9.8
      Z=20.
C
      ETA=(P0*((T0-GAM*Z)/T0)**(G/(R*GAM))-PT)/(P0-PT)
      DETA=1.-ETA
C
      WRITE(51,10)DETA
   10 FORMAT(F12.10)
      STOP
      END
