Accession Number : ADA047816

Title :   Tornado Identification from Analyses of Digital Radar Data.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Pittman,Donald Wayne

PDF Url : ADA047816

Report Date : Dec 1976

Pagination or Media Count : 104

Abstract : An investigation was conducted to determine whether tornadoes presented a unique signature in analyses of digital radar data from central Oklahoma during the Spring. The data were collected by the 10-cm-WSR-57 radar at the National Severe Storms Laboratory at Norman, Oklahoma. Three types of numerical analyses were used in this study: constant-altitude reflectivity maps (CAZM), total vertically-summed reflectivity maps (TVSZ), and partial vertically-summed reflectivity maps (PVSZ), with greatest emphasis placed on the PVSZ maps. Presentations covering a 100-km square were constructed at either 5 to 10 min intervals. From the analysis of three case studies during during 1974 and 1975, that contained five tornadoes, it was concluded that tornadoes did not produce a singular identifying signature in analyses of digital radar data, but rather produced a combination of features which indicated, with a high probability, the presnce of a tornado. Such features were the appearance of a small area of reduced reflectivity known as a Bounded Weak-Echo Region (BWER), a tilt of the core of the storm toward the BWER, and a rapid decrease in the upper-level mass of the storm as indicated by a rapid decrease in the reflectivity of the upper PVSZ.

Descriptors :   *TARGET SIGNATURES, *METEOROLOGICAL RADAR, *RADAR SIGNATURES, *TORNADOES, DATA PROCESSING, EXPERIMENTAL DATA, IDENTIFICATION, VERTICAL ORIENTATION, REFLECTIVITY, ALTITUDE, RADAR MAPPING, S BAND, SPRING SEASON, TILTMETERS

Subject Categories : Meteorology
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE