Call number:
ZSP-202-245
In:
Research report
Description / Table of Contents:
CONTENTS: Preface. - Abstract. - Introduction. - Snow crystals in Greenland. - Microspherules. - Microspherules in snow and ice-fog crystals. - Concentration and radii of spherules. - Discussion and conclusions. - Literature cited.
Description / Table of Contents:
Spherules found in snow crystals, ice-fog crystals, fallout particles, and fly ash were studied with an electron microscope using the electron diffraction method. The central part of the residues of 1004 specimens of natural snow crystals from Greenland, the United States, and Japan were examined; 14 spherules 0.1 to 1.5? in radius were found among them. The residues of 658 artificial ice-fog crystals formed from water vapor in flue gases of coal-burning electric power plants at Fairbanks, Alaska, were also examined; nine spherules were found. Spherules similar to those found in ice-fog residues were found in furnace-produced fly ash fallout at Fairbanks, Alaska. Electron and optical microscope examination of spherules found in Greenland snow reveals a size distribution of the form dN/d(log r) = Cr-ß where ß approximately 3. The properties of spherules and the mean mass of snow crystals from Greenland are described. The electron microscope study indicated that less than 0.7% of the 1004 snow crystals contained spherules of possible extraterrestrial origin, and that snow crystals are formed mainly on clay mineral particles by heterogeneous nucleation.
Type of Medium:
Series available for loan
Pages:
iv, 10 Seite
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 245
URL:
https://apps.dtic.mil/sti/citations/tr/AD0691326
Language:
English
Location:
AWI Archive
Branch Library:
AWI Library
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