When and why air can be cooler than ground just below: A theory for the Ramdas effect

Abstract

This paper offers a brief summary of new theoretical resolution of a sixty-year old paradox, concerning the observation, on calm clear nights, of a minimum in air temperature withm less than a metre of the ground. The background to the problem is presented, and the physical basis of the new theory described. It is shown that two factors ignored in all previous discussions of the problem, namely, surface emissivity and thermal conductivity of the soil, play crucial roles in determing when a lifted minimum occurs.