Journal Article

PreJuSER-111832

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png On the mixing-driven formation of the Extratropical Transition Layer (ExTL)

Konopka, P.FZJ* ; Pan, L. L.

2012
Union Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/20385  doi:10.1029/2012JD017876

Abstract: We present a case study on the formation and structure of the Extratropical Transition Layer (ExTL) using in situ observations and a Lagrangian chemical transport model. The results show that the model with mixing parameterized from the large-scale flow deformations well reconstructs the observed asymmetric structure of the ExTL with a deeper transition layer on the cyclonic side of the jet stream. Information from the model and observations are integrated using tracer-tracer correlations between ozone (O-3) and carbon monoxide (CO). Transport of chemical tracers from the stratospheric or tropospheric background to the ExTL through mixing is identified by the change of the CO-O-3 correlation in the CO-O-3 space. The ExTL formation process simulated by the model, therefore, provides a scenario to connect the mixed air parcels to the history of mixing. An estimate of timescales of ExTL formation is made using model experiments. The results show that the fastest formation of the ExTL occurs on the isentropic levels below the subtropical jet core, e.g. around 3 weeks for 310 K, whereas at 360 K level (jet core) the formation of the ExTL needs around 3 months. Overall, this result demonstrates the important role of mixing in transport of trace gases across the tropopause.

Keyword(s): J

Note: We thank William J. Randel for many discussions motivating the authors to conduct this study and to write this paper. We are also grateful to Anne Kunz, Rolf Muller and two anonymous reviewers for their very helpful comments. Important support by the preparation of the final version of the manuscript was provided by Shawn Honomichl. The European Centre for Medium-Range Weather Forecasts (ECMWF) provided meteorological analyses for this study.

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Contributing Institute(s):

1. Stratosphäre (IEK-7)

Research Program(s):

1. Atmosphäre und Klima (P23)

Appears in the scientific report 2012

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Database coverage:
; ; Current Contents - Agriculture, Biology and Environmental Sciences ; Current Contents - Social and Behavioral Sciences ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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