An Investigation of Arctic Surface, TOA, and Atmospheric Radiation Budgets using Collocated Surface and Satellite Observations over Barrow, Alaska

The Arctic is undergoing significant environmental changes due to climate warming, and acts as an early warning system for the rest of globe with indications of climate change being more apparent. Arctic clouds are the dominant modulators of radiation at both the surface and top of atmosphere (TOA), and have been identified as playing a central role in several hypothesized feedback processes by the SEARCH program. To investigate the impacts of Arctic clouds on surface, TOA, and Atmospheric radiation budgets, we have collected seven years of collocated surface and satellite observations over the Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) and NOAA/CMDL Barrow Observatory (BRW) during the period 2002-2008. The surface data are averaged over a 2-hour interval centered at the time of the satellite overpass, and the satellite (Terra and Aqua) data were averaged within a 1^o x 1^o area centered on the ARM NSA site. The surface cloud properties and radiation fluxes are derived/measured from the ground-based ARM and NOAA measurements at Barrow, and the satellite results are retrieved/measured from MODIS and CERES observations over Barrow, Alaska. In this study we will use combined satellite-surface observations to investigate the following three questions:

1) Can we statistically validate the satellite-retrieved cloud properties using the ground-based observations and retrievals during the 7-yr period?

2) How well do the satellite-derived surface radiation fluxes agree with the surface measurements?

3) What are the Arctic surface radiation and TOA radiation budgets, as well as derived atmospheric radiation budget?