Accession Number:

ADA058127

Title:

Vertical Structure in Atmospheric Fog and Haze and its Effects on IR Extinction.

Descriptive Note:

Research and development technical rept.,

Corporate Author:

ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND WSMR NM ATMOSPHERIC SCIENCES LAB

Report Date:

1978-07-01

Pagination or Media Count:

135.0

Abstract:

Vertical structure of the size distribution and number concentration of particulates in atmospheric fog and haze near Grafenwoehr, West Germany, was measured with a balloon-borne light-scattering aerosol counter for periods spanning parts of 8 days in February 1976. The work was part of a US Army field exercise conducted for the purpose of determining the effect of atmospheric constituents on various night vision systems. For haze approximately 5 km visibility conditions, little vertical variation is seen but for low visibility 1 km fog conditions, significant vertical increases in concentration of droplets with radii larger than 4 micrometers are seen over the first 150 m altitude. Liquid water content values for haze and fog range from 0.0001 to 0.45 gcu m. Extinction calculated from the particle size distributions shows an approximate 1lamba wavelength dependence for haze conditions, but nearly neutral wavelength independent extinction for heavy fog. A correlation exists between calculated particulate extinction and calculated liquid water content, independent of particle size distribution, for the fogs and hazes studied.

Subject Categories:

  • Meteorology
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE