Studies of the surface energy balance of the earth (SEB) often show that measured incoming energy exceeds the sum of measured outgoing energy terms. The present study models two contributions to the outgoing terms of the SEB: (a) water vapor and dry air as non-ideal gases and (b) the contribution of evaporation to the convective heat. As anticipated, the results are insufficient to resolve the closure mystery, but they should provide insights into atmospheric thermodynamics and the SEB.