Comparison of Daily Broadband Surface Albedos Measured at Six Extended Facilities in the ARM Southern Great Plains Cloud and Radiation Testbed
Hamm, K.G., University of Oklahoma
Twelfth Atmospheric Radiation Measurement (ARM) Science Team Meeting
An analysis of time series of daily hemispherical broadband surface albedo for 1998-1999 from six ARM Extended Facilities has been performed. The results show that the mean annual albedo differs by as much as 30% among the six sites. The annual range of daily albedos also varies among the sites. For example, albedos measured at the tallgrass prairie near Pawhuska, OK show a range of daily albedo between 0.15 and 0.20 for 1998, while daily albedos measured at a grazed pasture near Cordell, OK for the same time period have a range between 0.17 and 0.24 (or 40% higher than at Pawhuska). Differences in the extent of vegetation cover appear to cause some of the observed variations in albedo between locations. Analysis of biweekly composites of maximum NDVI derived from the NOAA-14 Advanced Very High Resolution Radiometer (AVHRR) show modest correlation between surface albedo and vegetation at some locations and weak correlation at others. The second source of variation is surface wetness. Examples of the connection between antecedent precipitation and albedo will be shown using ARM and Oklahoma Mesonet rain gauge data.
Note: This is the poster abstract presented at the meeting; an extended version was not provided by the author(s).


