flwupa=ice_emissivity*stefan*tsf**4
dflwupdT=4. _d 0*ice_emissivity*stefan*tsf**3
WRITE(iUnit,*) 'BlkF: ice_emissivity =',ice_emissivity
& snow_emissivity, ice_emissivity,
ice_emissivity = .98 _d 0
_RL ice_emissivity