_RL ssq0, ssq1, ssq2 ! constant used in surface specific humidity
DATA ssq0, ssq1, ssq2
ssq = ssq0*exp( lath*(ssq1-ssq2/Tsf) ) / p0
dEvdT = clha*ssq*ssq2/(Tsf*Tsf)
ssq = ssq0*exp( lath*(ssq1-ssq2/toa) ) / p0
_RL ssq,ssq0,ssq1,ssq2
ssqa = ssq0*exp( lath*(ssq1-ssq2/local)) / p0
_RL ssq0,ssq1,ssq2,lath,p0,ssqa