References

ACPD

Atmospheric Chemistry and Physics Discussions

ACPD

1680-7375

Copernicus GmbH

Göttingen, Germany

10.5194/acpd-10-30473-2010

High-ozone layers in the middle and upper troposphere above Central Europe: potential import from the stratosphere along the subtropical jet stream

Trickl

¹ Bärtsch-Ritter

² Eisele

¹ Furger

² Mücke

¹ Sprenger

³ Stohl

⁴ ⁵

Karlsruher Institut für Technologie, Institut für Meteorologie und Klimaforschung (IMK-IFU), Kreuzeckbahnstr. 19, 82467 Garmisch-Partenkirchen, Germany

Paul Scherrer Institut, Labor für Atmosphärenchemie, 5232 Villigen PSI, Switzerland

Eidgenössische Technische Hochschule (ETH) Zürich, Institut für Atmosphäre und Klima, Universitätsstr. 16, 8092 Zürich, Switzerland

Lehrstuhl für Ökoklimatologie, Technische Universität München, Am Hochanger 13, 85354 Freising-Weihenstephan, Germany

now at: Norwegian Institute for Air Research, P.O. Box 100, Instituttveien 18, 2027 Kjeller, Norway

15 12 2010

10 12 30473 30537

This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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Specific very dry high-ozone layers have been repeatedly observed in the middle and upper troposphere with the ozone lidar in Garmisch-Partenkirchen (Germany), starting roughly two days after the onset of high-pressure periods during the warm season. These episodes, previously not understood, were recently analysed based on extended simulations with the FLEXPART particle dispersion model and jet-stream analyses with the LAGRANTO transport model. The model results indicate import from the stratosphere along the subtropical jet stream over the Pacific Ocean and all the way back to the Atlantic Ocean, in some cases mixed with stratospheric air from intrusions over the North-West Pacific Ocean. Occasionally, also air from the boundary layers of East Asia and North America was admixed. The analysis suggests that stratospheric influence is the most important factor for the increase in ozone and is related to a rather shallow transfer of air from the stratosphere into the rapid upper-and mid-tropospheric air streams observed with the lidar. The in part considerable vertical and temporal extent of these layers and peak ozone mixing ratios between 80 and 150 \unit{ppb} suggest this to be an important mechanism for stratosphere-to-troposphere transport.

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