Dept. of Atmospheric Science, Colorado State University
Abstract
Includes bibliographical references (page 28).November 1976.Significant differences in US and USSR aircraft measurements of hemispherical infrared irradiance were noted during GATE in-flight intercomparisons. In specific instances the downward irradiance measured by the USSR instrument (a Kozyrev pyrgeometer) was as much as 1.5 times greater than the irradiance measured with the US instrument (an Eppley pyrgeometer). A post-GATE intercomparison at Colorado State University verified these differences; the pyrgeometer measurements were compared with independent measurements obtained with an infrared bolometer and with a radiative transfer calculation. The differences noted during GATE and post-GATE intercomparisons may be attributed to differences in calibration techniques and the accurate determination of the temperature of the instrument's thermopile cold junctions. When corrections based upon this analysis were applied to the USSR data, the maximum intercomparison differences were less than 5 percent