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

10. ADDITIONAL RELATED ANAL YSES.............................................................................................81
lOa. Comparisons of TAR Ice Particle Concentrations for Seeded and Nonseeded EUs............... 81
lOb. Comparison of2003/04 Experimental Period Precipitation to Long-Tenn Average ............85
lOco Supercooled Liquid Water Availability and Implications for Seeding Potential................... 86
IOd. Estimation of Possible Seasonal SWE Increases from Propane Seeding ..............................88
1 Od.l. Estimation of Seasonal Percentage Increases of SWE........................................... 88
10d.2. Speculation concerning Seasonal Volume Increases ofSWE ............................... 90
lOe. Examination of Precipitation Gauge Network Observations ................................................. 91
1 Oe.l. Comparisons of Daily Gauge Totals ...................................................................... 91
10e.2. Distributions of Daily Precipitation ....................................................................... 94
10e.3. Distributions of Hourly Precipitation .....................................................................94
10f. Relationships between TAR SL W, Winds and Precipitation Rate ......................................... 97
11. CONCLUSIONS AND RECOMMENDATIONS ............................................................................. 100

11 a. Overview.......... .......... ........ .................. ............. ................. ....... ............. ......... ............ ........ 100
11 b. Statistical Conclusions ........ ............ ............... ................. ........... ........... ...................... ......... 102
11 c. Estimated Precipitation Increases... ........ ......... ............ ............ ........... ............ ............ .......... 103
lId. Recommendations for Further Development of Propane Seeding...................................... 103

ACKNOWLEDGEMENTS............... ........................, .................................... ............. .......... .......... ......... 104

REFERENCES ........ ........ ........... ......... .......... .................... ........... ............. .......... ..................... ................ 105

APPENDIX A - Statistical Tests Applied to Regression ........................................................................ 109
APPENDIX B - Listing of Experimental Units ...................................................................................... 112
APPENDIX C -- Public Data Access ...................................................................................................... 114

Tables

Tabk Page

1. Instrumented sites used for the 2003/04 experiment, ordered by distance from HAS................... 20

2. Utah propane seeding experiment sites and instrumentation......................................................... 21

3. Periods with no TAR ACSII and/or 2D-C imagery data for six or more hours............................. 33

4. Summary of significance testing for regression fits to target-control data .................................... 46

5. Summary of pairs analysis for all 47 available EU pairs ............................................................... 50

6. Summary of the Wilcoxon tests using all 98 EUs ......................................................................... 51

7. Summary of ratio analyses for all 98 EUs :.................................................................................... 52

8. Summary of tests using all 98 available EUs with no partitioning ................................................53

9. HAS direction partition: from 169 to 270 deg inc\usive................................................................ 54

10. Summary ofSWE observations for 29 EUs with HAS median wind directions greater than 270

deg....... .......... .......... .......... .......... ............ ....... ............ .............. .......... ... ........... ............. ........ ......... 55

11. Icing Partition: icing detected at one or more of the following: HAS, SIR, TAR and TSO.......... 57