WMOD00462

• Contract/Permit #: 87-1999
• Title: Development of Empirical Equations of Ice Crystal Growth Microphysics for Modeling Analysis - Final Report
• Date: 9/1/1988
• Weather Modification - Doc Type: Report

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Specifically, this chapter is designated to make for each data set an

overview of the advantages and disadvantages of the techniques and an

analysis to consider the involved consistencies and errors. After having each

set processed, a comparative analysis will be made so that the strengths and

weaknesses of the empirical basis can be determined.

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Analysis of Each Data Set

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Fukuta (1969)

The experimental apparatus consisted of two cloud chambers with one

chamber mounted on top of the other. Both chambers were vertical square

tunnels each with double walls separated by a 70 percent aqueous glycerine

solution that was chilled and circulated to cool the inside air.

The upper chamber was made of copper with the inner and outer walls

having a width of 10.5 em and 14.5 em, respectively. The lower chamber was

composed of Plexiglas and had a black cloth along the inside wall but was

6 mm from the sides to prevent frost buildup. The inner and outer walls

measured corresponding widths of 9.6 em and 15.5 em. The heights of the

lower and upper chambers were 50.5 em and 61.5 em, respectively.

The upper chamber served to cool the fog to some predetermined

temperature. The source of moisture was an electrically warmed water in a

cellulose acetate semipermeable membrane placed at the top. As the water

vapor diffused downward, the air became saturated, and fog formed by

activation of condensation nuclei. The chilled copper wan prevented warm

air from reaching to the lower chamber.

The lower part of this chamber also supplied a location for ice crystals to

form. A hollow brass rod chilled with dry ice swung around once during

each experimental run to create small ice crystals by homogeneous

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