RAINDROP DISTRIBUTIONS NEAR FLAGSTAFF, ARIZONA.

Abstract

The Illinois State Water Survey raindrop camera was operated from 9 July through 19 August 1967 at the Fort Valley Experimental Forest near Flagstaff, Arizona, before, during, and after a period of cloud seeding. Drop-size distributions were determined for showers which were seeded and unseeded and showers with and without the occurrence of hail. It was found, on the average, that seeded showers and natural showers forming in more humid air masses have fewer large drops and more drops per cubic meter for the same rainfall rate than have showers accompanied by hail and unseeded showers forming in relatively dry air masses. The increase in the relative number of drops at rainfall rates greater than 30 mm hr was investigated and found to be the result of the breakup of drops larger than 2.0 mm diameter. It is concluded that the peculiarity of the Flagstaff distributions lies in the extraordinary number of very large drops which fall in showers forming in relatively dry air and that these large drops do not break up easily because they are the remnants of hailstones. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1969
Accession Number
AD0685031

Entities

People

  • Douglas M. A. Jones

Tags

DTIC Thesaurus Topics

  • Air Masses
  • Biological Phenomena
  • Diameters
  • Drops
  • Ecological And Environmental Phenomena
  • Ecological And Environmental Processes
  • Hail
  • Illinois
  • Meteorological Phenomena
  • Raindrops
  • Rainfall

Readers

  • Aerosol Science/Aerosol Physics
  • Mathematics or Statistics
  • Solar Physics