Skip to main content
Have a personal or library account? Click to login
Effects of the Tibetan Plateau on total column ozone distribution Cover

Effects of the Tibetan Plateau on total column ozone distribution

Open Access
|Jan 2008

Abstract

The relatively low total column ozone (TCO) above the Tibetan Plateau (TP) observed in summer is only partly due to the thinness of the atmospheric column. In this paper the effect of the TP on the TCO is further investigated using satellite data [Total Ozone Mapping Spectrometer (TOMS) ozone column and Stratospheric Aerosol and Gas Experiment II (SAGE II) ozone profiles], ECMWF ERA-40 reanalysis data and a 3-D chemistry-climate model (CCM). It is found that the low TCO over the TP is also closely related to large-scale uplift and descent of isentropic surfaces implied by seasonal and longitudinal variations in the tropopause height. The variations in tropopause height, with a maximum in summer, can be driven by various processes including convective activity, air expansion as well as the monsoon system. While previous studies have showed an important role of troposphere-to-stratosphere transport in contributing to the observed low ozone column over the TP, the mechanism revealed in this study is an alternative amendment to the causes of the TCO low over the TP. It is also found that the monsoon anticyclone circulation induces an isentropic transport of trace gases from high latitudes towards the TP in the lower stratosphere and hence modifies tracer distributions. For the vertical distribution of ozone, the modulation by the TP is most significant below ~ 20 km, that is, in the upper troposphere and lower stratosphere (UTLS). The smaller differences in NOx between Eastern TP and TP compared to large dynamically caused differences in ozone and methane imply the TCO low over the TP is mainly due to transport processes rather than chemistry.

Language: English
Page range: 622 - 635
Submitted on: Apr 15, 2007
Accepted on: Dec 10, 2007
Published on: Jan 1, 2008
Published by: Stockholm University Press
In partnership with: Paradigm Publishing Services

© 2008 Wenshou Tian, Martyn Chipperfield, Qian Huang, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.