Thermodynamic Cycle of the Atmospheric Upward Heat Convection Process

Summary ?Closed ideal thermodynamic cycles are used to analyze the atmospheric upward heat convection process which is compared to the Brayton gas-turbine cycle. The heat to work conversion efficiency of the atmosphere is shown to be close to the Carnot efficiency calculated using the average temperatures at which heat is received and given up for hot and cold source temperatures, respectively. The efficiency is independent of whether the lifting process is discontinuous or continuous, and nearly independent of whether the heat is transported as sensible or as latent heat. The total energy given up by an air mass going through any process is shown to be equal to the reduction in its static-energy. For a given sounding, there is a definite quantity of work which can be produced per unit mass of air raised. The paper investigates how updraft and sounding properties affect the work produced when air is raised and shows that the work can be transferred downward. Received March 19, 1999/Revised September 24, 1999