Accession Number : ADA188862

Title :   Sky Polarization Data for Volcanic and Non-Volcanic Periods.

Descriptive Note : Rept. for Apr-Sep 86,

Corporate Author : OPTIMETRICS INC BURLINGTON MA

Personal Author(s) : Longtin, David R ; Volz, Frederic E

PDF Url : ADA188862

Report Date : Oct 1986

Pagination or Media Count : 71

Abstract : Volz has monitored the Arago and Babinet neutral points at Lexington and Bedford, Mass. for the years 1968 to 1986. Theses data, along with measurements of turbidity, twilight color ratio, solar aureole and cloud and snow cover, have been assembled into a database and checked for error. The neutral point data were then corrected for day to day variations in tropospheric turbidity and separated into groups which coincide with time periods of known volcanic influences and seasonal events. 3-D plots indicate that both the Arago and Babinet points were strongly affected by the presence of the El Chichon dust cloud; however, the features were not as pronounced as in the tropics. Measurements made after the El Chichon eruptions also suggest a movement of the neutral points after sunset which was not observed after the eruptions of Mt. Pelee in 1902 and Katmai in 1911. The present measurements did not show an effect from the eruptions of Fuego in 1971 and late 1974.

Descriptors :   *DUST CLOUDS, *POLARIZATION, *AEROSOLS, *LIGHT SCATTERING, COLORS, DATA BASES, RATIOS, SEASONAL VARIATIONS, SKY, SNOW COVER, TIME INTERVALS, TROPOSPHERE, TURBIDITY, TWILIGHT, EARTH ATMOSPHERE, VOLCANOES, CLOUD COVER, THREE DIMENSIONAL, TROPICAL REGIONS, VISUAL PERCEPTION

Subject Categories : Atmospheric Physics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE