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The unsuitability of meteoritic and other nuclei for polar stratospheric cloud freezing
Author(s) -
Biermann U. M.,
Presper T.,
Koop T.,
Mößinger J.,
Crutzen P. J.,
Peter Th.
Publication year - 1996
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl01577
Subject(s) - meteorite , stratosphere , astrobiology , polar , meteoroid , nucleation , freezing point , atmospheric sciences , geology , mineralogy , chemistry , physics , astronomy , thermodynamics , organic chemistry
Bulk freezing experiments have been performed with binary and ternary HNO 3 /H 2 SO 4 /H 2 O solutions containing original micrometeorites, ground samples of representative larger meteorites and other freezing nuclei of potential stratospheric importance. The experiments enable us to determine upper bounds for the heterogeneous freezing rates of sulfuric and nitric acid hydrates. Based on an analysis of the meteoritic mass flux from space and of the modifications meteorites undergo when entering the atmosphere, the resulting morphology and surface area of extraterrestrial material in the stratosphere are estimated. From this micrometeorites gained from Antarctica are shown to be a good proxy for meteoritic surfaces in the stratosphere. In combination with this analysis the freezing experiments suggest that heterogeneous nucleation rates on micrometeorites are too low to enhance freezing of polar stratospheric clouds above the frost point.