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ATMOS measurements of H 2 O+2CH 4 and total reactive nitrogen in the November 1994 Antarctic stratosphere: Dehydration and denitrification in the vortex
Author(s) -
Rinsland C. P.,
Gunson M. R.,
Salawitch R. J.,
Newchurch M. J.,
Zander R.,
Abbas M. M.,
Abrams M. C.,
Manney G. L.,
Michelsen H. A.,
Chang A. Y.,
Goldman A.
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 - 10.1029/96gl00048
Subject(s) - stratosphere , vortex , polar vortex , atmospheric sciences , physics , climatology , meteorology , geology
Simultaneous stratospheric volume mixing ratios (VMRs) measured inside and outside the Antarctic vortex by the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument in November 1994 reveal previously unobserved features in the distributions of total reactive nitrogen (NO y ) and total hydrogen (H 2 O+2CH 4 ). Maximum removal of NO y due to sedimentation of polar stratospheric clouds (PSCs) inside the vortex occurred at a potential temperature (Θ) of 500–525 K (∼20 km), where values were 5 times smaller than measurements outside. Maximum loss of H 2 O+2CH 4 due to PSCs occurred in the vortex at 425–450 K, ∼3 km lower than the peak NO y loss. At that level, H 2 O+2CH 4 VMRs inside the vortex were ∼70% of corresponding values outside. The Antarctic and April 1993 Arctic measurements by ATMOS show no significant differences in H 2 O+2CH 4 VMRs outside the vortices in the two hemispheres. Elevated NO y VMRs were measured inside the vortex near 700 K. Recent model calculations indicate that this feature results from downward transport of elevated NO y produced in the thermosphere and mesosphere.