WMOD00378

• Title: Physical Investigations of Winter Orographic Clouds in Utah
• Date: 3/1/1984
• State: UT
• Weather Modification - Doc Type: Report

microwave radiometer, a zenith-pointing K u-band radar, and a zEmith-

pointing polarization diversity lidar were deployed.

They collected data

on the amount of liquid water in the clouds overhead and in other direc-

tions, on the reflectivity structure, temporal variation, and convective

or stratiform nature of the clouds overhead, and on the liquid or solid

phase, crystal habit, and extent of riming or melting of the hydromE!teors

in the clouds overhead. A C-band surveillance radar was deployed Wl~st of

the Tushar Mtns to collect data on the general types of precipitation

echoes. A detector of supercooled liquid water was located on the upper

slopes of the Tushar Mtns to collect data on this variable at low altitude

in the clouds passing over the mountains.

Precipitation gages were

located at various altitudes up the slopes of the Tushar Mtns to collect

data on the amount, duration, and rate of precipitation. Rawinsondes were

launched from a site west of the Tushar Mtns to collect data on the ver-

tical structure of the atmosphere. A research aircraft collected data on

liquid water content and other cloud physics variables in the upper levels

of the study clouds.

I n order adequately to examine the great amount of data collected a

stratified analysis approach was taken in much of the work. The approach

considers the relationship of two or more variables over all the STORMS

encountered in the field investigations and draws a broad picture of the

study clouds. The case study approach which describes in detail a single

STORM or part of a STORM has been utilized in some places. (The STqRM. was

the research study unit and was a period of significant cloud cover and

weather typ.ically 18-24 hr long. There were twenty STORMS in the 1983

,....._R.~ .C' ~_.._..-

research period.)

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