ICRCCM phase II: Verification and calibration of radiation codes in climate models. Final report, 1 May 1990--30 April 1993

Following the finding by the InterComparison of Radiation Codes used in Climate Models (ICRCCM) of large differences among fluxes predicted by sophisticated radiation models that could not be sorted out because of the lack of a set of accurate atmospheric spectral radiation data measured simultaneously with the important radiative properties of the atmosphere, the team of scientists proposed to remedy the situation by carrying out a comprehensive program of measurement and analysis called SPECTRE (Spectral Radiance Experiment). SPECTRE was to establish an absolute standard against which to compare models, and aimed to remove the hidden variables (unknown humidities, aerosols, etc.) which radiation modelers had invoked to excuse disagreements with observation. The data collected during SPECTRE were to form the test bed for the second phase of ICRCCM, namely verification and calibration of radiation codes used in climate models. This should lead to more accurate radiation models for use in parameterizing climate models, which in turn play a key role in the prediction of trace-gas greenhouse effects. This report summarizes the activities during the project`s Third year to meet stated objectives. The report is divided into three sections entitled: (1) SPECTRE Activities, (2) ICRCCM Activities, and (3) Summary Information. The section on SPECTRE activities summarizes the field portion of the project during 1991, and the data reduction/analysis performed by the various participants. The section on ICRCCM activities summarizes their initial attempts to select data for distribution to ICRCCM participants and at comparison of observations with calculations as will be done by the ICRCCM participants. The Summary Information section lists data concerning publications, presentations, graduate students supported, and post-doctoral appointments during the project