Spectroscopic detection of COClF in the tropical and mid-latitude lower stratosphere

TY - JOUR

T1 - Spectroscopic detection of COClF in the tropical and mid-latitude lower stratosphere

AU - Rinsland, Curtis P.

AU - Nassar, Ray

AU - Boone, Chris D.

AU - Bernath, Peter

AU - Chiou, Linda

AU - Weisenstein, Debra K.

AU - Mahieu, Emmanuel

AU - Zander, Rodolphe

PY - 2007/7

Y1 - 2007/7

N2 - We report retrievals of COClF (carbonyl chlorofluoride) based on atmospheric chemistry experiment (ACE) solar occultation spectra recorded at tropical and mid-latitudes during 2004-2005. The COClF molecule is a temporary reservoir of both chlorine and fluorine and has not been measured previously by remote sensing. A maximum COClF mixing ratio of 99.7 +/- 48.0 pptv (10(-12) per unit volume, 1 sigma) is measured at 28 km for tropical and subtropical occultations (latitudes below 20 degrees in both hemispheres) with lower mixing ratios at both higher and lower altitudes. Northern hemisphere mid-latitude mixing ratios (30-50 degrees N) resulted in an average profile with a peak mixing ratio of 51.7 +/- 132.1 pptv, 1 sigma, at 27 km, also decreasing above and below that altitude. We compare the measured average profiles with the one reported set of in situ lower stratospheric mid-latitude measurements from 1986 and 1987, a previous two-dimensional (2-D) model calculation for 1987 and 1993, and a 2-D-model prediction for 2004. The measured average tropical profile is in close agreement with the model prediction; the northern mid-latitude profile is also consistent, although the peak in the measured profile occurs at a higher altitude (2.5-4.5 km offset) than in the model prediction. Seasonal average 2-D-model predictions of the COClF stratospheric distribution for 2004 are also reported. (c) 2006 Elsevier Ltd. All rights reserved.

AB - We report retrievals of COClF (carbonyl chlorofluoride) based on atmospheric chemistry experiment (ACE) solar occultation spectra recorded at tropical and mid-latitudes during 2004-2005. The COClF molecule is a temporary reservoir of both chlorine and fluorine and has not been measured previously by remote sensing. A maximum COClF mixing ratio of 99.7 +/- 48.0 pptv (10(-12) per unit volume, 1 sigma) is measured at 28 km for tropical and subtropical occultations (latitudes below 20 degrees in both hemispheres) with lower mixing ratios at both higher and lower altitudes. Northern hemisphere mid-latitude mixing ratios (30-50 degrees N) resulted in an average profile with a peak mixing ratio of 51.7 +/- 132.1 pptv, 1 sigma, at 27 km, also decreasing above and below that altitude. We compare the measured average profiles with the one reported set of in situ lower stratospheric mid-latitude measurements from 1986 and 1987, a previous two-dimensional (2-D) model calculation for 1987 and 1993, and a 2-D-model prediction for 2004. The measured average tropical profile is in close agreement with the model prediction; the northern mid-latitude profile is also consistent, although the peak in the measured profile occurs at a higher altitude (2.5-4.5 km offset) than in the model prediction. Seasonal average 2-D-model predictions of the COClF stratospheric distribution for 2004 are also reported. (c) 2006 Elsevier Ltd. All rights reserved.

KW - remote sensing

KW - stratospheric chemistry

KW - infrared atmospheric remote sounding

KW - measurement-model comparisons

KW - stratospheric chlorine chemistry

KW - stratospheric fluorine chemistry

KW - FOURIER-TRANSFORM SPECTROMETER

KW - INFRARED SOLAR SPECTRA

KW - 2-DIMENSIONAL MODEL

KW - GLOBAL INVENTORY

KW - FLUORINE

KW - CHLORINE

KW - CHEMISTRY

KW - RETRIEVALS

KW - EMISSIONS

KW - TRANSPORT

U2 - 10.1016/j.jqsrt.2006.11.013

DO - 10.1016/j.jqsrt.2006.11.013

M3 - Article

VL - 105

SP - 467

EP - 475

JO - Journal of Quantitative Spectroscopy and Radiative Transfer

JF - Journal of Quantitative Spectroscopy and Radiative Transfer

SN - 0022-4073

IS - 3

ER -