WMOD00404

• Title: Thailand Applied Atmospheric Research Program - Final Report - Volume II
• Date: 3/1/1994
• Weather Modification - Doc Type: Report

CONTENTS

Page

Glossary and acronyms ....................................................... iii

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1

2. Design of the Thai cold cloud rainmaking demonstration project ....................... 4
2.1 Statement of the problem . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 4
2.2 Principles of cold cloud seElding for rain enhancement ...............,..... 4
2.3 Summary of results relevant to Thailand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4 Summary of Thai cold cloud seeding experiments . . . . . .. . . . . . . . . . . . . . . . . . . 6

2.4.1 Introduction ................................................ 6
2.4.2 Design of the Thai cold cloud seeding and its implementation . . . . . . . . . . . 7
2.4.3 Results to date .............................................. 8
2.5 Implications of the results of the exploratory experimentation on the design
of the cold cloud demonstration project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6 General experimental guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.7 The conceptual model for the cold cloud seeding demonstration project . . . . . . . . . . . 9
2.8 Specification of the design variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.8.1 Experimental unit ........................................... 9
2.8.2 Treatment units ............................................ 10
2.8.3 The project study area ....................................... 10

2.8.4 Randomization ............................................. 10

2.8.5 Type of nucleant and means of delivery .......................... 10
2.9 Experimental procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
2.9.1 Forecasting procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
2.9.2 Flight procedures ........................................... 11
2.10 Projected duration of the demonstration project. . . . . . . . . . . . . . . . . . . . . . . . . .. 14

2.11 Evaluation............................................ . . . . . . . . . .. 15

2.11.1 Evaluation parameters ...................................... 15
2.11.2 Approach ................................................ 15
2.11.3 Accounting for natural biases ................................. 17
2.11.4 Statistical significance tests .................................. 20
2.11.5 Seed versus no seed comparisons .............................. 21
3. Design of the Thai warm cloud rainmaking demonstration project . . . . . . . . . . . . . . . . . . . . . 22
3.1 Statement of the problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22
3.2 Principles of warm cloud seeding for rain enhancement ................... 22
3.3 Summary of results ofrel,evance to Thailand. . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4 Summary of warm cloud seeding model experiments ..................... 24

3.4.1 Introduction ............................................... 24
3.4.2 Results to date .............................. . . . . . . . . . . . . . . . 24
3.5 Implications of model seeding results on the design of the warm cloud
seeding demonstration project ...................................... 25
3.5.1 Seeding agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.5.2 Seeding strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.5.3 Additional studies . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . 26
3.6 The conceptual model for the warm cloud seeding demonstration project. . . . . . . . . 26
3.7 Warm cloud seeding hypothesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.8 General experimental design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.9 Specification of design variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.9.1 Experimental unit .......................................... 27
3.9.2 Treatment units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.9.3 Randomization ............................................. 29
3.9.4 Type of nucleant and means of delivery .......................... 29

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