Accession Number:

ADA071455

Title:

Infrared Absorption by Water Clusters.

Descriptive Note:

Final rept. Aug 76-Sep 78,

Corporate Author:

ARMY ARMAMENT RESEARCH AND DEVELOPMENT COMMAND ABERDEEN PROVING GROUND MD CHEMICAL SYSTEMS LAB

Personal Author(s):

Report Date:

1979-03-01

Pagination or Media Count:

45.0

Abstract:

This report summarizes the results of a two-year study of atmospheric infrared continuum absorption attributed to intermolecularly bonded clusters in water vapor. Spectral data are reviewed for water vapor, steam and liquid water. The infrared continuum absorption is discussed in detail and is shown to be explicable on the basis of homogeneous or ion-induced cluster distributions in water vapor, where the cluster population is approximately proportional to the square of the partial water vapor pressure. Thermodynamic consistency between the vapor and liquid phases is discussed for temperatures including the critical 374 C where the phases become one. Simple oscillator models are shown to give agreement with observed spectral lines, suggesting certain cluster configurations. The ion concentration of moist air versus temperature is discussed, and measurements of ion cluster distributions are considered. Cluster absorption at longer wavelengths including the microwave region is discussed. Conclusions are presented.

Subject Categories:

  • Atmospheric Physics
  • Atomic and Molecular Physics and Spectroscopy
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE