WMOD00317

• Contract/Permit #: 14-06-D-6999
• Project Name: CAWRP
• Title: Cascades Atmosphere Water Resources Program - Volume I
• Prepared For: US Department of the Interior Bureau of Reclaimation
• Date: 7/1/1970
• Weather Modification - Doc Type: Report

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- ll5 -

Although the combinations of side planes, bullets, and columns (83)

occurred under water-saturated conditions, bullets and columns were not always

indicative of water saturation. According to Magono and Lee (1966) hollow

columns can grow at just ice saturation but water saturation is needed for

hollow bullets. Further clarification and additional investigations are needed

in urder to determine the degree of hollowness and characteristics of columns
and bullets as a function of humidity.
These crystal types were subject to break-up in the air when the
individual crystals were attached to a central branch.
4.2.14 Solid and Hollow Bullets and Combinations of Bullets (Clc, Cld,
and C2a)
According to Magono and Lee (1966), solid bullets grow at temperatures
below -20oC in a sub-water saturated atmosphere, whereas, hollow bullets can
only grow at temperatures below -250C in a water-saturated environment.
Magono and Lee state that combinations of bullets grow at temperatures below
about -250C in a watey.-saturated environment and that only hollow bullets are
involved in combinations. Ono found that hollow bullets might grow at
temperatures below -220C.
Our aircraft observations indicated that solid and hollow bullets grow at
temperatures below -190C. Combinations of bullets were not observed at

temperatures warmer than about -250C under water-saturated conditions. Thus~

our observations for solid bullets are in good agreement with those of Magono

and Lee. Between -20 to -250C there might be a gradual transition from a soH.d

to a completely hollow bullet under water-saturated conditions. Further work

is needed to determine the degree of hollowness of bullets as a function of