Traditionally albedo has been measured with combined sets of tower-based-downward and upward-looking instruments. However, this measured local albedo may not be representative of a larger area averaged surface albedo that encompasses an inhomogeneous surface with many different local albedos. Because most radiative transfer calculations require an area-averaged albedo, the use of a local albedo may be responsible for large uncertainties in these calculations.
The new technique uses only data from the MFRSRs and calculates the albedo during overcast cases at MFRSR wavelengths using an assumption of the 415 nm albedo and the near spectral independence of the cloud optical depth.
Data are currently available from the SGP from January 2008 to December 2012. It is planned to also run this VAP at other sites in the future with even more inhomogeneous terrain, like the Azores and other coastal sites. Feedback on the data set is requested to help direct future development.
For questions or to report data problems, please contact Laura Riihimaki. Browse the data set here or log in to the ARM Data Archive. (Go here to request an account).
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The ARM Climate Research Facility is a national scientific user facility funded through the U.S. Department of Energy’s Office of Science. The ARM Facility is operated by nine Department of Energy national laboratories.