WMOD00400

• Contract/Permit #: 14-06-D-6801
• Title: Structure and Seedability of San Juan Storms
• Date: 11/1/1976
• Weather Modification - Doc Type: Report

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TABLE OF CONTENTS

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1.

INTRODUCTION . .

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1. The presence of supercooled water
2. Relatively low ice crystal concentrations
3. A delivery mechanism for the AgI
4. Sufficient residence time

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DATA USED IN STOR}f SYNTHESIS

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Aircraft Flight Operations
1. Operational periods
2. Air traffic control
3. Research area
4. Typical flight plan

Ground Data

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B.
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H. S. S. I. data
1. Snowfall data
2. Ice nucleus data

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E.G. & G. Data .

SU}frfARY OF }fAJOR RESULTS AND CONCLUSIONS

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Storm Structure and Sequence
1. Typical storm
a. Stable stage .
b. Neutral stage
c. Unstable stage
d. Dissipation stage
2. An atypical but very organized storm

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B. Hicrophysical Characteristics
l. Liquid 'vater observations
a. Region over and slightly upwind of the mountain
barrier . . . . . 22
b. Associated with the upHind rise in the terrain 26
c. Associated ,.;rith convection 26
2. Ice crystal observations 29
a. Concentrations . . 29
b. Trajectories . . . . . 31
c. Precipitation-forming mechanisms 33
d. An effect of the upwind topography 34
e. Cirrus seeding . . 34
f. Ice crystal origins 35
3. Ice nucleus measurements 38
a. Langer filter samples 38
b. Scavenging of AgI 41
c. HHlipore f il tor samples 42
d. Dust as an ice nucleus 42

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