Randel, WJ, Wu, F and Forster, P (2007) The extratropical tropopause inversion layer: Global observations with GPS data, and a radiative forcing mechanism. Journal of the Atmospheric Sciences, 64 (12). 4489 - 4496 . ISSN 0022-4928Full text available as:
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Global characteristics of the extratropical tropopause inversion layer identified in radiosonde observations by Birner are studied using high vertical resolution temperature profiles from GPS radio occultation measurements. The GPS data are organized according to the height of the thermal tropopause in each profile, and a temperature inversion layer above the tropopause (with an average magnitude of 3-5 K) is found to be a ubiquitous, climatological feature. The GPS data show that the inversion layer is present for all seasons in both hemispheres, spanning the subtropics to the pole, and there is not strong longitudinal structure. Dependence of the inversion layer on upper-troposphere vorticity is studied; while anticyclones exhibit a substantially stronger inversion than cyclones (as expected from balanced dynamics), the inversion is evident for all circulation types. Radiative transfer calculations indicate that strong gradients in both ozone and water vapor near the tropopause contribute to the inversion. Significant absorption of both longwave and shortwave radiation by ozone occurs, warming the region above the tropopause. Water vapor near and immediately above the tropopause contributes to cooling, effectively enhancing the inversion.
|Copyright, Publisher and Additional Information:||© 2007 American Meteorological Society. Reproduced in accordance with the publisher's self-archiving policy.|
|Keywords:||dynamical tropopause, radio occultation, atmosphere, stratosphere|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds)|
|Depositing User:||Symplectic Publications|
|Date Deposited:||12 Oct 2011 11:06|
|Last Modified:||08 Jun 2014 16:21|
|Publisher:||American Meteorological Society|