WMOD00412

• Title: Final Report on Utah Cloud Seeding Experimentation Using Propane During the 2003/04 Winter
• Date: 3/1/2005
• State: UT
• Weather Modification - Doc Type: Report

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CONTENTS - continued

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6.

Frequency distribution of HAS wind directions for 59 experiments with good, fair or poor TAR
targeting conducted during the winters of 1994/95 and 1995/96............................................,...... 14

7.

Frequency distribution of TAR wind directions for 59 experiments with good, fair or poor TAR
targeting conducted during the winters of 1994/95 and 1995/96................................................... 15

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8.

ETI precipitation gauge at GNO control site with view toward the north. .................................... 22

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9. Central propane dispenser and tower at HAS with view toward the south-southeast.................... 22

10.

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Southeast propane dispenser at HAS during a test release with view toward the southeast.......... 23

11.

Scale drawing of the Goodrich Model 872Fl icing rate sensor..................................................... 24

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12.

Frequency versus time from the Goodrich icing rate sensor during the first EU on 14 December

2003 . ........ .......... .......... .......... ......... .......... ....... ... ........... ......... .............. ....... ............. .......... ........... 25

13.

Goodrich icing rate sensor and nearby sensors on morning of 1 March 2003............................... 28

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14.

The TAR instrumented target facilities in early winter looking toward the west-southwest......... 30

15.

The top of the instrumented platform at TAR with view toward the northwest ............................31

16.

Plots of 50 seeded and 48 nonseeded SWEs for GTR versus GNO .............................................. 47

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17.

Time history of TAR 2D-C probe observatories of ice particle concentration during 3 adjoining
experimental periods on 21 December 2003.................................................................................. 71

18.

Bar graphs of precipitation accumulation at 4 high resolution gauges during the 3 adjoining
experimental periods of Fig. 17 .... .... ............,.. ......... ................... .......... .......... .......... .......... .......... 73

19.

Thirty second "snapshots" of2D-C images during peak ice particle concentration times for the 3
adjoining experimental units of 21 December 2003 shown on Fig. 18 .........................................76

20.

Similar to Fig. 19 but for a 2 min period of natural snowfall (upper panel) ending 3 min before the
estimated arrival of the propane seeding plume with the lower panel showing a 1 min period of
seeding starting 4 min after the estimated arrival time .................................................................. 77

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21.

Similar to the two previous 2D-C image figures but the upper two panels are 30 sec snapshots
beginning at 1225 and 1238 MST, exactly 1/3 and 2/3 of the way through the estimated 40 min
period of seeding plume passage by the TAR................................................................................ 78

22.

Ice particle concentrations versus SWE at GTR for 21 seeded and 22 nonseeded EUs with HAS

wind direction <= 270 deg... .......... ........... ........... ....... ............... ........... ........... .......... .................... 84

23.

Cumulative distributions of daily SWE at GTR for 60 days with significant snowfall................. 95

24.

Similar to Fig. 23 but for hourly, not daily precipitation............................................................... 96

IX

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