Accession Number : ADA300324

Title :   Microphysical Studies of Noctilucent Clouds.

Descriptive Note : Final technical rept.,

Corporate Author : STATE UNIV OF NEW YORK AT ALBANY

Personal Author(s) : Vonnegut, Bernard

PDF Url : ADA300324

Report Date : JAN 1992

Pagination or Media Count : 7

Abstract : Very little is understood about the microphysics of noctilucent clouds. It is not known whether the ice crystals comprising them are of cubic habit, as has been suggested, or whether they are hexagonal, as in tropospheric clouds. It has not been established whether the crystal habit and the crystal growth rates are influenced or controlled by the nuclei present in the upper atmosphere, or whether temperature and humidity conditions play the dominant role in that respect as in the troposphere. It is clear, however, that the size and shape of the individual crystals determine their optical properties and therefore determine how noctilucent clouds interact with transmissions of electromagnetic waves. Our experiments were aimed at revealing the habit of noctilucent cloud particles.

Descriptors :   *OPTICAL PROPERTIES, *NOCTILUCENT CLOUDS, CRYSTAL STRUCTURE, ICE, CRYSTAL GROWTH, HUMIDITY, UPPER ATMOSPHERE.

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE