- 102 - 



The energy heat flux falling on the ground depends only on the 

 phase of the precipitation, not additionally on the temperature 

 of the rain or snow; this is an inaccuracy, but the error is a 

 relatively small portion of the total flux. Rain over ice 

 immediately runs into the ocean. SNOW (kg/m 2 ) accumulates on the 

 surface. Over land ice, when the snow exceeds 100 (kg/m 2 ), some 

 of it is compacted into ice so that the snow depth is reset to 90 

 (kg/m 2 ). The compacted ice is accumulated (with a minus sign) in 

 the diagnostic MANDC . 



Evaporation is calculated in the surface interaction routine 

 and depends on the surface drag, surface wind magnitude, surface 

 specific humidity, and the ground temperature. 



EEVAP (W/m 2 ) = EVAP * LH 



LH = 2500000 (J/kg) over water 

 LH = 2834000 (J/kg) over ice 



EVAP is the evaporation in kg/m 2 s 

 The temperature at which evaporation occurs is ignored. 



Runoff over ice is the summation of rain plus melting of 

 snow or ice at the surface, represented by RUNOFF 9kg/m 2 s). 

 Runoff carries no energy with it. Over earth, runoff depends on 

 whether the ground is saturated and the energy of runoff is 



ERUN (W/m 2 ) = RUNOFF * T (°C) * SHW [SHW = 418 5 (J/kg°c)] 



