Development of rotating shadowband spectral radiometers and GCM radiation code test data sets in support of ARM. Technical progress report, September 15, 1992--October 31, 1993

The ARM goal is to help improve both longwave and shortwave models by providing improved radiometric shortwave data. These data can be used directly to test shortwave model predictions. As will be described below they can also provide inferred values for aerosol and cloud properties that are useful for longwave modeling efforts as well. The current ARM research program includes three tasks all related to the study of shortwave radiation transfer through clouds and aerosol. Two of the tasks involve the assembly of archived and new radiation and meteorological data sets; the third and dominant task has been the development and use of new shortwave radiometric sensors. Archived data from Golden, Colorado, and Albany, New York, were combined with National Weather Service ground and upper air data for testing radiation models for the era when the Earth Radiation Budget Experiment (ERBE) was operational. These data do not include optimum surface radiation measurements; consequently we are acquiring downwelling shortwave, including direct and diffuse irradiance, plus downwelling longwave, upwelling shortwave, and aerosol optical depth, at our own institution, as an additional dataset for ARM modelers.