Wednesday, 23 January 2008
Combination of measurements from a millimeter wave cloud radar and a high spectral resolution lidar at Eureka
Exhibit Hall B (Ernest N. Morial Convention Center)
The climatology and microphysical characteristics of arctic clouds at Eureka, a weather station located in the Canadian Arctic, on Ellesmere Island (80°N, 86.2°W) over a period of one and half year are presented. Eureka is outfitted with a millimeter wavelength cloud radar (MMCR) similar to these operated by the US Department of Energy Atmospheric Radiation Measurement (ARM) program and an Arctic High Spectral Resolution Lidar (AHSRL) provided by the University of Wisconsin. We combined the profiling measurements of the MMCR (reflectivity, mean Doppler velocity and spectral width) and AHSRL (particulate backscatter cross section and the depolarization ratio) to study cloud morphology and climatology. Hourly statistics of cloud fraction, number of cloud layer, cloud overlap and cloud type fraction are derived. Estimates of hydrometeor phase (liquid, ice or mixed-phase) for clouds and precipitation are provided. The diurnal and seasonal variability of the retrieved parameters is discussed.