Surface Heat Exchange

From page A-88 of the manual the equation for Term-by-Term surface heat exchange is: Hn = Hs + Ha + He + Hc - ( Hsr + Har + Hbr ) He = f(W) (es - ea) & Hc = Cc f(W) (Ts-Ta) This tells me when water surface temperatures are warmer than air temperatures then He and Hc are positive and the heat flux is into the water. I found a manual given at the 2000 workshop and the same equation for net heat exchange is in that manual (page 33) with a slight difference: Hn = Hs + Ha [b]-[/b] He [b]-[/b] Hc - ( Hsr + Har + Hbr ) He and Hc are now negative. This make more sense to me. When water temperatures are warmer than air temperatures then He and Hc are negative and the heat flux is to the air. Can anyone tell me which equation is correct and what the model is using in its computations?[/b]