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

page

EXECUTIVE SUMMARY ............................................................................................................."............. i

I. SA CKG ROUND ....... .................. ................ ............... .......... ...... ............... ................. ........................ ...... 1
2. REASONS FOR TESTING AND IMPROVING PROPANE SEEDING TECHNOLOGy................... 1
3. RANDOMIZED EXPERIMENTAL DESIGN ..........................................................................."............ 4

3a. Design Overview........ .............. .......................... .................. .............,....... .......................... ....... 4
3b. Experimental Design of 2003/04 Utah Program........................................................................ 6
4. ANALYSES OF PRIOR PLUME TRACING AND SEEDING EXPERIMENTS .................................. 7
4a. Examination of Early 1991 Observations ....................................................................."............9
4b. Examination of Early 1994 Observations .................................................................................. 9
4c. Examination of 1994/95 and 1995/96 Observations ................................................................ 13
5. PRECIPITATION MEASUREMENT CONSIDERATIONS .....................................................".......... 16
Sa. Precipitation Gauge Considerations ..... ........... .................................. .................... ........".......... 16
5b. Minimizing Wind-Induced Gauge Undercatch ........................................................................ 16
5c. Locating Suitable Gauge Sites for the Randomized Experiment ............................................. 18

6. FACILITIES ... .................. ....... ..... .............................. ......... .................... ......... ...... ..... ....... ......... ".......... 20

6a. Overview....... ........... ................ ...... ....... .......................... ... ....... .... .... ....... ....... ...... ...... ..".......... 20
6b. Precipitation Gauge Sites.......... ............ ........... .................... ............... ....... ...................... ........ 20
6c. High Altitude Seeding Site.......... ............... ........... .................. ..................... ............................ 20
6c.l. Overall Facilities............. ........... ........... ...................... ...... ................ ........... .".......... 20
6c.2. Problems with HAS Icing Sensors ............................................................................ 23

6d. TAR Observatory .......... ............................. ........... .............................. ................... ............. ..... 29
6d.l. The TAR data acquisition system ............................................................................ 30
6e. SIR and TSO Icing Stations ..................................................................................................... 33
7. STATISTICAL TECHNIQUES .............................................................................................................34

7 a. Regression analysis ....... ................................ ........... ................................. ......................... ...... 35
7b. Analysis of SINS and S-NS Pairs ............................................................................................ 36
7 c. N onparametric Inference Technique.. ............ ................... .......... .................. ........... ......... ........ 37

7 d. Ratio Statistics.... ........... ........................................... ........... ............. ......... ............. ......".......... 3 8
7 e. Random Number Generator .... ................... ........... ................ .......... .................. .......... ............. 40
7f. Notes on Testing Techniques ................................................................................................... 41
8. RESULTS OF STATISTICAL ANAL YSIS .......................................................................................... 44
8a. Finalizing EU selection and calculating plume transit times ................................................... 44

8b. Regression Analysis ........ ........................................... ................. ..... .......... ......................... ..... 46
8c. Notes on Application of Statistical Analysis Packages............................................................ 48

8c.l. Pairs analysis.... .......... .................. ............... .......... ...... ................. ...................... ...... 49
8c.2. Wilcoxon Nonparametric Analysis........ .......................... ..................... ........ ........... 50
8c.3. Ratio testing: rerandomized MDR and Confidence Intervals ................................... 51
8d. Partitioning Experimental Units into Subpopulations with Similar Characteristics ................ 52
8d.l. Partitioning by HAS Wind Direction....................................................................... 54
8d.2. Partitioning by SL W ...... ............ ............................... .................... ........................... 55
8d.3. Partitioning by HAS Temperature ........................................................................... 57
8d.4. Partitioning by Two Parameters................................................................................ 58
8d.5. Wind Speed Partition ............................................................................................... 61
8d.6. Summary of Partitioning Results .............................................................................. 62
8d.7. Summary of Partitioning by Gauge .........................................................................64
8d.8 Application of Median Double Ratios ...................................................................... 67
9. PHYSICAL CASE STUDY EXPERIMENT ......................................................................................... 67
9a. Case Study of 21 December 2003 ............................................................................................ 69

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