WMOD00413

• Title: Validation of Precipitation Management by Seeding Winter Orographic Clouds in the Colorado River Basin
• Date: 9/1/1993
• Weather Modification - Doc Type: Report

Embedded convection: convective cells rising within and usually above a layer cloud. Weak
embedded convection is visible, by the appearence of small cloud turrets, above many
orographic clouds.

FAA: Federal Aviation Administration.

FONSI: finding of no significant impact.

FWCA: Fish and Wildlife Coordination Act.

Flux (SLW): the rate offlow ofSLW (e.g., over a mountain barrier).

GFE: government-furnished equipment.

GPS: global positioning system.

GS: Geological Survey.

Glaciogenic cloud seeding: seeding designed to add ice particles to clouds, whether by chilling
the air below - 40 oC to accomplish homogeneous ice nucleation (without the involvement of ice
nuclei), or by addition of artificial ice nuclei to acheive hetrogenerous ice nucleation.

graupel: snow pellets formed by accretion (capture and freezing) of supercooled cloud droplets
on falling ice crystals.

HIPLEX-l: High Plains Cooperative Program Experiment.

IFR: instrument flight rules.

ILS: instrument landing system.

IPC: ice particle concentration.

Ice nuclei: tiny particles that serve to create ice crystals in the atmosphere; clay and other
natural materials mixed through the atmosphere often serve as ice nuclei, and some
manufacturing processes add ice nuclei. Silver iodide is the most common type of artificial ice
nuclei.

in situ: Latin. in its original place (e.g., within a cloud).

Lee subsidence: the downward motion and associated warming in the lee (downwind side) of
an orographic barrier that results in rapid evaporation of cloud droplets and sublimation of ice
particles.

Lidar: similar to radar, but using energy at or near visible light wavelenths. A lidar ceilometer
can monitor cloud base elevation.

m.s.!.: mean sea level.

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