IEM Daily Feature
Tuesday, 08 January 2013

Latent Heat Flux

Posted: 08 Jan 2013 05:36 AM

Above freezing temperatures and sunshine helped to melt some of our snow in Iowa on Monday. The featured chart is of latent heat flux from the one of the NLAE flux sites since the first of the year. Latent heat is a measure of the energy being transferred from the surface to the atmosphere as the result of evaporation or sublimation of water. In this context, a positive number is a transfer of energy to the atmosphere. The large spike on Monday is certainly indicative of the enhanced snow melt, sublimation, and evaporation that was occuring. These processes require heat, so it acts to slow the surface air heating rate as energy is consumed to change the phase of water. This is a big reason why near surface air temperatures can not get too warm with snow on the ground.

Good = 26
Bad = 5

Tags:   flux