Community Research and Development Information Service - CORDIS

Studies on processes responsible for distribution and evolution of O3 and H2O in troposphere and lower stratosphere

Summary: The existence of ozone-rich transients in the tropical and subtropical high troposphere has been discovered from MOZAIC data obtained during flights crossing the Equator. Several explanations have been proposed, but this strongly suggests that the input of stratospheric air into the troposphere can take place in the tropics. (LA/CNRS)
The existence and the seasonal variability of the Atlantic subtropical potential vorticity barrier, controlling the stratosphere-troposphere exchanges between the lowermost extratropical stratosphere and the upper equatorial troposphere has been evidenced and documented.
The mean stratosphere/troposphere exchange in the region of the polar jet was analyzed in a statistic way using MOZAIC water vapour and ozone measurements.
MOZAIC observations have shown that in the upper troposphere the specific humidity in the mid-latitudes and subtropics exhibit a pronounced biannual cycle which is strongly coupled to the seasonal cycle of the temperature.
An investigation of low ozone concentrations and conditions when they occur was started by MPI. Almost all episodes were found in the tropics, with half of events occurring just after a peak in the ozone concentration and most of them being likely to be associated with local convection.

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Alain MARENCO
Tel.: +33-5-61332732
Fax: +33-5-61332733
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Record Number: 24433 / Last updated on: 2000-05-16
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Collaboration sought: Information exchange/Training
Stage of development: Other