Pore-scale thermal signatures of drying porous surfaces

During gradual drying of porous media surface pores are invaded by the air from largest to smallest sequentially, resembling the drainage process in which evaporating wetting liquid is displaced by the air. The emptying of an evaporating pore is accompanied by changes in the thermal field forming on the surface around the invaded pore that consequently affects surface temperature and energy partitioning over the drying surfaces.

In this work we investigate thermal interaction between adjacent evaporating pores on the surface using microscopic infrared thermography and evaluate the effect of pore spacing on the pore scale thermal adjustments and per-pore evaporative flux. Results of the present study enable to systematically link drying-induced pore emptying sequences with thermal adjustments and energy partitioning over drying terrestrial surfaces.