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ARS Home » Pacific West Area » Boise, Idaho » Northwest Watershed Research Center » Research » Publications at this Location » Publication #65829
Title: ESTIMATING LARGE SCALE VORTICITY FROM SINGLE DOPPLER RADAR DATA

Author
item LU, YUNYUN - UNIVERSITY OF IDAHO
item DOVIAK, RICHARD - NOAA/NSSL NORMAN OK
item Johnson, Gregory

Submitted to: American Meteorological Society
Publication Type: Proceedings
Publication Acceptance Date: 6/1/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: A study was undertaken to develop a procedure for estimating vorticity, or rotation, in the atmosphere directly from new Doppler weather radar. Vorticity estimates are extremely important for determining the potential for storm development, and for discerning the horizontal wind field over a region. The procedure uses a commonly used technique (the Velocity Azimuth Display, or VAD technique) for determining horizontal wind fields from radar-measured wind velocities. This technique can be applied to weather situations when, for example, fronts might be within the surveillance domain, or where the effect of complex terrain might be significant. Comparing the surface value of vorticity, extrapolated from the estimated profiles, with the vorticity calculated from the dense network of wind reporting sites in the surface Oklahoma MESONET network, good agreement was found. Vertical profiles of vorticity also were consistent with numerical weather analyses.

Technical Abstract: A computationally-simple numerical model for wind flow over complex terrain was aplied to the Reynolds Creek Experimental Watershed (RCEW) in southern Idaho. MS-Micro/3 was evaluated as a potential model for developing realistic wind climatologies over complex terrain, as well as for simulating wind flow during hydrologically-important events. A typical winter storm over southern Idaho was chosen as a study case. A ten-hour simulation was performed for a storm on March 16, 1993. Simulated wind fields on a 250m resolution grid were displayed using a Geographic Information System (GIS). Simulated results were statistically analyzed and compared to observations in the watershed. The code was found to be computationally simple to run, and provided a possible numerical tool for climatic wind studies at the watershed scale.