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Stratospheric BrO profiles measured at different latitudes and seasons: Atmospheric observations
Author(s) -
Harder H.,
CamyPeyret C.,
Ferlemann F.,
Fitzenberger R.,
Hawat T.,
Osterkamp H.,
Schneider M.,
Perner D.,
Platt U.,
Vradelis P.,
Pfeilsticker K.
Publication year - 1998
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 - 10.1029/1998gl900026
Subject(s) - sunset , atmospheric sciences , environmental science , troposphere , altitude (triangle) , zenith , stratosphere , daytime , latitude , solar zenith angle , ozone , mixing ratio , ozone depletion , meteorology , remote sensing , geology , physics , geodesy , geometry , mathematics , astronomy
Stratospheric BrO profiles were measured at different latitudes and in different seasons in 1996/97 during three flights of the LPMA/DOAS balloon gondola (LPMA/Laboratoire Physique Moléculaire et Application and DOAS/Differential Optical Absorption Spectrometry). Using direct sunlight DOAS spectrometry the following BrO mixing ratios were measured; (1) 9 to 14 ppt in the height range from 20 to 30 km (at solar zenith angles, SZA < 88°) during ascent, (2) about (14±2) ppt for altitudes above the balloon float altitude at 30.6 km, 30.0 km, and 39.8 km, and (3) 5 to 10 ppt in the 20–30 km region during sunset. The lower BrO concentrations during sunset than those observed prior at daytime indicate a conversion of BrO into nighttime reservoir species (BrONO 2 , HOBr, and BrCl). The overall agreement of our UV spectroscopic BrO profiles with recent measurements using the chemical conversion/resonance fluorescence technique is good. Our BrO profiles are also in reasonable agreement with the present stratospheric Br y burden and chemistry. Conversily collocated ground‐based and satellite column measurements, however, show significantly more total atmospheric BrO (50–100%) than the integrated stratospheric BrO balloon profiles can account for. This indicates a global tropospheric BrO background, estimated at 1–2 ppt.