Comparison of SHEBA and NSA Cloud Properties for April, May, June and July

Cloud radar, cloud lidar and radiometer data sets from the Surface Heat Budget of the Arctic (SHEBA) and DOE/Atmospheric Radiation Measurement North Slope of Alaska (NSA) sites are presently being processed with a suite of retrieval techniques to produce detailed records of cloud microphysical properties over full annual cycles. The first step of this process is to identify which clouds are all-ice, which are all-liquid, which are mixed phase, and what instruments were operating correctly, so that the correct retrieval technique can be subjectively selected for each case. The first priority in the processing procedure is choose the simple cases where clouds are both single layer and single phase, and reliable, validated retrieval techniques can be applied.

For both SHEBA and NSA, one simple all-ice, and one simple all-liquid case will be selected for each month of the year and examined to provide an initial preview of the kinds of seasonal variations that will be observed at the two sites for the two different cloud types. In addition, the percentage of mixed phase clouds for each month of the year will be presented, and the overall data quality and instrument calibrations will be discussed for each site. Because the SHEBA and NSA data sites overlap in time by 7 months in 1998, this study will also serve to provide initial comparisons between the properties of the clouds observed in the Arctic Ocean and the coastal Alaskan location respectively.