WMOD00402

• Project Name: Sierra Cooperative Pilot Project
• Title: Sierra Cooperative Pilot Project - Final Report for Period November 1984 - September 1986
• Date: 6/1/1987
• Weather Modification - Doc Type: Report

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5

Sec1:ion VI.

It.-Band Radar Measurement aDd Analvsis Proqra!!

This radar, built at DRI, was desiqnt!d to operate in the vert1.cal-
pointinq mode at a hiqh mountain site in lfinter.

It usually operated alonqside a microwave radiometer used to measure
liquid water and water vapor in approximately the same beam coverage reqions
as the radar. 'ftle back-scattered radiatic)D of the Ka radar yielded valuable
information, as time series displays, on c::loud base and cloud-top heiqhts,
chanqes in reflec1:ivity and band structure in the cloud systellUl. 'l:'he bands
could be either wverticalw precipitation reqions movinq across the reqion,
or whorizontalW layers representinq preciJ~itation-sized particulates at
several levels in the cloud mass.

The proqram supported upqrades and mc)difications to the radar system
itself includinq color-displays and sophilsticated data acquisition and
storaqe systems.

Both winter seasons covered by the C()ntract yielded val\lable data
which has been analyzed and reported in o)nferences and workshops. Probably
the most valuable contributions the radar has made to this proqram are: (a)
to identify reqions of precipitation qrowth, particularly in the lower cloud
reqions over the mountainous terrain, and (b) to define the c~loud base and
top elevations continuously throuqhout tht! observing' periods, enablinq
reasonable estimates to be made of the concentrations of liq\llid water in
the cloud, based on the inteqrated radiomt!ter measurements. Details of
individual case studies are qiven in the text of Section VI.