10 to 12 μm Spectral Emissivity of a Cirrus Cloud

Abstract

A balloon flight made 4 February 1970 with an infrared spectral radiometer system scanning from 10 to 13 ?m ascended through an extensive cirrus cloud. This allowed measurements to be made of the spectral radiance of the cloud both underneath and in the cloud as the balloon ascended. The spectra obtained are presented and the data were used to determine the emissivity of the cloud at 11 ?m. The value ?=0.38 is in reasonable agreement with values found by Kuhn and Weickmann.