HR: 1330h
AN: H23A-21    [Abstracts]
TI: Improving Radar Snowfall Measurements Using a Video Disdrometer
AU: Newman, A J
EM: andrew.newman@und.nodak.edu
AF: University of North Dakota, Department of Atmospheric Sciences P.O. Box 9006 University of North Dakota, Grand Forks, ND 58201 United States
AU: * Kucera, P A
EM: pkucera@aero.und.edu
AF: University of North Dakota, Department of Atmospheric Sciences P.O. Box 9006 University of North Dakota, Grand Forks, ND 58201 United States
AB: A video disdrometer has been recently developed at NASA/Wallops Flight Facility in an effort to improve surface precipitation measurements. The recent upgrade of the UND C-band weather radar to dual-polarimetric capabilities along with the development of the UND Glacial Ridge intensive atmospheric observation site has presented a valuable opportunity to attempt to improve radar estimates of snowfall. The video disdrometer, referred to as the Rain Imaging System (RIS), has been deployed at the Glacial Ridge site for most of the 2004-2005 winter season to measure size distributions, precipitation rate, and density estimates of snowfall. The RIS uses CCD grayscale video camera with a zoom lens to observe hydrometers in a sample volume located 2 meters from end of the lens and approximately 1.5 meters away from an independent light source. The design of the RIS may eliminate sampling errors from wind flow around the instrument. The RIS has proven its ability to operate continuously in the adverse conditions often observed in the Northern Plains. The RIS is able to provide crystal habit information, variability of particle size distributions for the lifecycle of the storm, snowfall rates, and estimates of snow density. This information, in conjunction with hand measurements of density and crystal habit, will be used to build a database for comparisons with polarimetric data from the UND radar. This database will serve as the basis for improving snowfall estimates using polarimetric radar observations. Preliminary results from several case studies will be presented.
DE: 1854 Precipitation (3354)
DE: 3354 Precipitation (1854)
DE: 3360 Remote sensing
DE: 3394 Instruments and techniques
SC: Hydrology [H]
MN: 2005 Joint Assembly