A THEORY OF ANNUAL TEMPERATURE VARIATIONS

Abstract

Solutions for the differential equation of heat flow as applied to the atmosphere and to the ground are related by surface boundary conditions. One condition represents a vertical energy balance involving annual variations of incoming solar radiation, albedo, surface heat loss due to evaporation, heat radiation from the surface to space, heat reradiation to the surface from clouds and water vapor, convective heat transport between air and the surface, and conductive heat transport between ground and the surface. Applied to climatological data, the solution for the atmosphere yields a coefficient of vertical heat exchange that is constant rather than variable with elevation, and also fairly close approximations to observed annual variations of potential temperatures near the surface at three widely separated continental stations. Poorer agreement between observed and theoretical variations at upper levels in the troposphere may be due to neglect of advection and localized heating and cooling aloft. Theoretical variations of temperature at various ground depths are quite close to observed variations.