WMOD00176

• Project Name: Annual Report
• Title: Seeding Operations & Atmospheric Research, 2005 Annual Report
• Prepared By: Duncan Axisia
• Date: 12/31/2005
• Weather Modification - Doc Type: Report

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Evaluation for the Texas Counties

Ten clouds were seeded and identified by TITAN over Gaines. Yoakum, and Terry Counties in 9
operational days over Texas. Two clouds did not get proper data

Small Clouds

Table 6 shows the results from the classic TIT AN evaluation for the 3 small seeded clouds which
obtained proper control douds.

Table 6: Seeded Sample versus Control Sample (3 couples. averages)

Variable Seeded Sample Control Sample Simple Ratio Increases (%)
lifetime 35 min 30 min 1.17 17 (30)
Area , , 0.71 -29 (8)
328 km 462km
Volume 67.8 km , 97.9km1 0.69 -31 (15)
Top Height 76 km 75 km '.01 1(1)
Max dBl 472 47.8 0.99 -1(1)
Top Height of 4.' km 4.3 km 0.95 5 (-10)
max dBZ
Volume S.9km-' 4.8km' 1.23 23(23)
Above 6 km
Prec. Flux 1875m'/s 311.8 m 'Is 060 -40(11)
Prec. Mass 355.6 kton 532.4 klon 067 -33 (44)
Cloud Mass 50.8 ktOn 84.8 kton 0.59 -41(12)
~ 7.0 6.3 1.11 11(30)

Bold values in parentheses are modeled values: whereas 11 is defined as the quotient of Precipitation
Mass divided by Cloud Mass. and is interpreted as efficiency (doud mass here is a fraction of the real
mass, that fraction the radar can detect). A total of 6 "ares were used in this sub-sample with an
excellent liming (83 %) for an effective dose aboul110 ice-nuclei per liter. A good increase of 44 % in
precipitation mass together with an increase of 12 % in doud mass illustrates that the seeded douds
grew at expenses of the environmental moisture (they were open systems) and used only a fraction of
this moisture for their ovm maintenance. The increases in lifetime (30 %) and precipitation mass is the
only one that seems to overcome the radar uncertainty. However. the sample is too small even for
deScriptions.

An increase of 44 % in precipitation mass for a control value of 532.4 kton in 3 cases means:

61 = 3 x 0.44 x 532.4 kton = 702.8 kton = 570 ae-f

47