Accession Number : ADA195344

Title :   Measurement of Vertical Velocity Using Clear-Air Doppler Radars,

Corporate Author : CONTROL DATA CORP MINNEAPOLIS MN METEOROLOGY RESEARCH CENTER

Personal Author(s) : VanZandt, T E ; Green, J L ; Nastrom, G D ; Gage, K S ; Clark, W L

PDF Url : ADA195344

Report Date : 25 Mar 1988

Pagination or Media Count : 3

Abstract : Since the development of the clear-air Doppler radar technique (also called the Wind-profiling or MST-radar technique) at Jicamarca, Peru (Woodman and Guillen, 1974), it has been applied to a wide range of meteorological problems (see, e.g., Liu and Kato, 1985). Despite this rapid progress, research on some important problems has been frustrated by the fact that most clear-air Doppler radars are near mountains. The resulting orographic effects act as geophysical noise on observations of other processes. These effects are especially serious for studies of the vertical component of motion. For example, Ecklund et al. (1982) found that when the wind flowed over the mountains, the variance of the vertical velocity was strongly correlated with the wind speed. Nastrom et al. (1985) found that they could extract the small synoptic-scale vertical velocity only when the horizontal wind was not from the direction of nearby mountains. Following their suggestion, we have constructed anew clear-air Doppler radar, called the Flatland radar, in very flat terrain near Champaign-Urbana, Illinois. We find that the vertical velocity field over very flat terrain is indeed quite different from that near rough terrain, and we present observations that suggest that the vertical velocity due to other processes, such as synoptic-scale motions and gravity waves, can be studied by clear-air Doppler radars in very flat terrain.

Descriptors :   *CLEAR AIR TURBULENCE, *DOPPLER RADAR, *GRAVITY WAVES, *MOUNTAINS, *WIND, GEOPHYSICS, HORIZONTAL ORIENTATION, ILLINOIS, MEASUREMENT, METEOROLOGY, MOTION, NOISE, PERU, RANGE(EXTREMES), ROUGHNESS, TERRAIN, VELOCITY, VERTICAL ORIENTATION, WIND VELOCITY

Subject Categories : Active & Passive Radar Detection & Equipment
      Atmospheric Physics
      Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE