TY  - JOUR
AU  - Suminska-Ebersoldt, O.
AU  - Lehmann, R.
AU  - Wegner, T.
AU  - Grooß, J.-U.
AU  - Hösen, E.
AU  - Weigel, R.
AU  - Frey, W.
AU  - Griessbach, S.
AU  - Mitev, V.
AU  - Emde, C.
AU  - Volk, C.  M.
AU  - Borrmann, S.
AU  - Rex, M.
AU  - Stroh, F.
AU  - von Hobe, M.
TI  - ClOOCl photolysis at high solar zenith angles: analysis of the RECONCILE self-match flight
JO  - Atmospheric chemistry and physics
VL  - 12
SN  - 1680-7316
CY  - Katlenburg-Lindau
PB  - EGU
M1  - PreJuSER-18761
SP  - 1353 - 1365
PY  - 2012
N1  - The RECONCILE project is funded under the European Commission Seventh Framework Programme (FP7) under the Grant number RECONCILE-226365-FP7-ENV-2008-1. The Ph.D. student position of Olga Suminska-Ebersoldt is financed within the ENVIVAL-LIFE project through a grant from Bundesministerium fur Wirtschaft (BMWi) via DLR, Germany.
AB  - The photolysis rate constant of dichlorine peroxide (ClOOCl, ClO dimer) J(ClOOCl) is a critical parameter in catalytic cycles destroying ozone (O-3) in the polar stratosphere. In the atmospherically relevant wavelength region (lambda > 310 nm), significant discrepancies between laboratory measurements of ClOOCl absorption cross sections and spectra cause a large uncertainty in J(ClOOCl). Previous investigations of the consistency of published JClOOCl with atmospheric observations of chlorine monoxide (ClO) and ClOOCl have focused on the photochemical equilibrium between ClOOCl formation and photolysis, and thus could only constrain the ratio of J(ClOOCl) over the ClOOCl formation rate constant k(rec). Here, we constrain the atmospherically effective J(ClOOCl) independent of k(rec), using ClO measured in the same air masses before and directly after sunrise during an aircraft flight that was part of the RECONCILE field campaign in the winter 2010 from Kiruna, Sweden. Over sunrise, when the ClO/ClOOCl system comes out of thermal equilibrium and the influence of the ClO recombination reaction is negligible, the increase in ClO concentrations is significantly faster than expected from J(ClOOCl) based on the absorption spectrum proposed by Pope et al. (2007), but does not warrant cross sections larger than recently published values by Papanastasiou et al. (2009). In particular, the existence of a significant ClOOCl absorption band longwards of 420 nm is not supported by our observations. The observed night-time ClO would not be consistent with a ClO/ClOOCl thermal equilibrium constant significantly higher than the one proposed by Plenge et al. (2005).
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000300656500009
DO  - DOI:10.5194/acp-12-1353-2012
UR  - https://juser.fz-juelich.de/record/18761
ER  -