SPECTRAL ANALYSIS OF INFRARED HEATING IN CLOUDS COMPUTED WITH TWO-STREAM RADIATION CODES

摘要

This paper examines the accuracy of two-stream methods for calculating infrared fluxes and heating rates within cloud, based on an idealized model of a cloud layer located in an otherwise clear column with fluxes incident upon the cloud top and cloud base specified at their clear sky values. The non-scattering limit is examined, because two-stream models should be selected to give good approximations in this limit so that the same algorithm can be used for both clear and cloudy sky. Not all two-stream methods meet this condition, and an example is provided of the consequent errors if the condition is ignored.