_RL frace, rs, hq
frace = 0. _d 0
frace = (iceFrac - lowIcFrac1)/(lowIcFrac2-iceMaskMin)
frace = MIN( enFrcMlt, MAX( 0. _d 0, frace ) )
frace = 1. _d 0
frace = fracEnMelt
frace = MIN( frace, fracEnMelt )
etop = (1. _d 0-frace)*sHeating * dt
etope = frace*sHeating * dt
ebote = frace*ebot