Investigation of Unusual Albedos in the SGP Domain
| Groff, David | ARM SGP |
| Duchon, Claude | University Of Oklahoma |
Category: Atmospheric State and Surface
We investigate the cause of unusually high albedos at an Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) extended facility near Morris, OK. In a previous study, daily albedos were calculated at several SGP extended facilities for 1998 and 1999 using broadband (.28 to 3 microns) pyranometers. The average daily albedo during this period was calculated to be at least about 5% higher at Morris than at any of the other SGP extended facilities. Surface based measurements of daily albedos at Morris and two nearby SGP extended facilities during 2004 and 2005 suggest the unusually high albedo measurements at Morris are real.
In our approach to account for the higher albedo, first Energy Balance Bowen Ratio (EBBR) soil moisture data at 30-minute intervals are averaged for each day in the latter two-year period. Linear regression analysis is then used to model the relationship between daily albedos and average daily soil moisture for each month in 2004 and 2005. Previous work has shown that bare soil albedo is strongly correlated with soil moisture. Therefore, this linear regression analysis may provide information about the vegetation density for each of the 24 months considered. The slopes of the 24 linear regression equations are plotted against monthly averages of daily albedos. We plan to use these plots to explain the extent to which the unusually high albedos at Morris are attributed to soil or vegetation.
This poster will be displayed at the ARM Science Team Meeting.
