WMOD00568

• Project Name: Snowater
• Title: Snow Water Augmentation for the Eastern Slopes of the Rockies - Stage I: Technology Adaptation
• Date: 6/1/1986
• Weather Modification - Doc Type: Report

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2 TECHNICAL PROPOSAL

2.1 INTRODUCTION

A strategy for cloud seeding to increase snowfall in the Oldman River
basin is presented. The general area of the proposed project is that
used during the Alberta Research Council SNOWPACK project and is shown
in Figure 3. This strategy is composed of two stages. SNOWATER I, the
subject of this proposal, adapts and develops snow augmentation
technology to the Alberta situation. SNOWATER II would be the
demonstration of this technology. If this demonstration is
successful, operational implementation could follow.

This section presents the basic structure of SNOWATER I Technology
Adaptation. A brief discussion of the principles of cloud seeding for
snow augmentation is given. This is followed by a summary of the
results from the recently completed Research Council winter climate
and cloud studies that examined the potential for snow augmentation in
Alberta. A section follows outlining the three key areas of activity
for the proposed program. The principal tasks for each project year
are then given. These are followed by a synopsis of overall project
components for each year and a budget.

2.2 BASIC PRINCIPLES OF OROGRAPHIC CLOUD SEEDING

The rationale of cloud seeding for snow augmentation is based upon the
fact that the atmosphere is not always naturally "efficient" in
producing precipitation. Considerable quantities of moisture are
contained in the atmosphere as it passes .over the mountains. For
example, in a moderate westerly air flow with clouds one kilometer
deep and extending one hundred kilometers (sixty miles) along the
mountains, about five thousand cubic meters (one million gallons) of
water pass over the mountains each minute. Some of this moisture
cor.denses to form clouds which often do not produce precipitation.

These clouds are composed of supercooled water droplets that often
remain in the liquid state at temperatures much colder than freezing
(ODC) due to a scarcity of ice nucleating materials. When ice
particles are present in these supercooled clouds, they grow at the
expense of the droplets and may eventually become large enough to
reach the surface as snow. In the absence of ice particles, the cloud
droplets evaporate in the descending air on the leeward side of the
mountain barrier~

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