Light Refraction by Mean Temperature Gradients in the Near-Earth Atmosphere.

Abstract

Visible light ray paths in the atmospheric surface layer are numerically computed by division of 500- to 5000-m ranges into small intervals so that the ray path height and thus the refractive index gradient is nearly constant for each step. Meteorological conditions are varied by using different combinations of sensible heat fluxes, surface stresses, and surface roughness. Although the effect of water vapor gradients can be substantial, their effect is not included here. The results are confined to heights less than five m because of the restrictive values chosen for the ratio of the eddy diffusivity of heat to that of momentum. Mirages hide lower portions of images and the minimum observable height varies approximately in inverse proportion to the observer height. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1974
Accession Number
AD0783484

Entities

People

  • Charles R. Stearns
  • Marvin L. Wesely

Organizations

  • Ballistic Research Laboratory

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Atmospheres
  • Diffusivity
  • Heat Flux
  • Intervals
  • Isotherms
  • Momentum
  • Observers
  • Physical Properties
  • Refraction
  • Refractive Index
  • Roughness
  • Surface Roughness
  • Temperature Gradients
  • Visible Spectra
  • Water Vapor

Fields of Study

  • Environmental science

Readers

  • Fluid Dynamics.
  • Solar Physics
  • Spectroscopy.