Title Physical properties of High Arctic tropospheric particles during winter
Author Bourdages, L.; Duck, T.J.; Lesins, G.; Drummond, J.R.; Eloranta, E.W.
Author Affil Bourdages, L., Dalhousie University, Department of Physics and Atmospheric Science, Halifax, NS, Canada. Other: University of Wisconsin
Source Atmospheric Chemistry and Physics, 9(18), p.6881-6897, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2009
Notes In English. Published in Atmospheric Chemistry and Physics Discussions: 24 March 2009, http://www.atmos-chem-phys- discuss.net/9/7781/2009/acpd-9-7781- 2009.html; accessed in May, 2011. 38 refs. GeoRef Acc. No: 310156
Index Terms aerosols; precipitation (meteorology); boundary layer; clouds (meteorology); crystals; ice; ice crystals; lasers; lidar; particles; physical properties; radar; remote sensing; Arctic Ocean; Arctic region; Canada-- Eureka; Canada--Nunavut; atmospheric precipitation; Canada; clouds; Eureka Canada; ice clouds; laser methods; lidar methods; Nunavut; radar methods; scattering properties; troposphere
Abstract A climatology of particle scattering properties in the wintertime High Arctic troposphere, including vertical distributions and effective radii, is presented. The measurements were obtained using a lidar and cloud radar located at Eureka, Nunavut Territory (80N, 86W). Four different particle groupings are considered: boundary- layer ice crystals, ice clouds, mixed-phase clouds, and aerosols. Two-dimensional histograms of occurrence probabilities against depolarization, radar/lidar colour ratio and height are given. Colour ratios are related to particle minimum dimensions (i.e., widths rather than lengths) using a Mie scattering model. Ice cloud crystals have effective radii spanning 25-220 m, with larger particles observed at lower altitudes. Topographic blowing snow residuals in the boundary layer have the smallest crystals at 15-70 m. Mixed-phase clouds have water droplets and ice crystal precipitation in the 5-40 m and 40-220 m ranges, respectively. Ice cloud crystals have depolarization decreasing with height. The depolarization trend is associated with the large ice crystal sub-population. Small crystals depolarize more than large ones in ice clouds at a given altitude, and show constant modal depolarization with height. Ice clouds in the mid-troposphere are sometimes observed to precipitate to the ground. Water clouds are constrained to the lower troposphere (0.5-3.5 km altitude). Aerosols are most abundant near the ground and are frequently mixed with the other particle types. The data are used to construct a classification chart for particle scattering in wintertime Arctic conditions.
URL http://www.atmos-chem-phys.net/9/6881/2009/acp-9-6881-2009.pdf
Publication Type journal article
Record ID 65006697