Skip to Main content Skip to Navigation
Journal articles

West African Monsoon observed with ground-based GPS receivers during African Monsoon Multidisciplinary Analysis (AMMA)

Abstract : The impact of stratospheric ozone on the tropospheric general circulation of the Southern Hemisphere (SH) is examined with a set of chemistry‐climate models participating in the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry‐Climate Model Validation project phase 2 (CCMVal‐2). Model integrations of both the past and future climates reveal the crucial role of stratospheric ozone in driving SH circulation change: stronger ozone depletion in late spring generally leads to greater poleward displacement and intensification of the tropospheric midlatitude jet, and greater expansion of the SH Hadley cell in the summer. These circulation changes are systematic as poleward displacement of the jet is typically accompanied by intensification of the jet and expansion of the Hadley cell. Overall results are compared with coupled models participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), and possible mechanisms are discussed. While the tropospheric circulation response appears quasi‐linearly related to stratospheric ozone changes, the quantitative response to a given forcing varies considerably from one model to another. This scatter partly results from differences in model climatology. It is shown that poleward intensification of the westerly jet is generally stronger in models whose climatological jet is biased toward lower latitudes. This result is discussed in the context of quasi‐geostrophic zonal mean dynamics.
Complete list of metadata

Cited literature [57 references]  Display  Hide  Download
Contributor : Catherine Cardon Connect in order to contact the contributor
Submitted on : Wednesday, March 16, 2016 - 12:36:17 PM
Last modification on : Friday, December 3, 2021 - 11:42:25 AM
Long-term archiving on: : Friday, June 17, 2016 - 10:31:06 AM


Publisher files allowed on an open archive



Olivier Bock, Marie-Noëlle Bouin, E. Doerflinger, P. Collard, F. Masson, et al.. West African Monsoon observed with ground-based GPS receivers during African Monsoon Multidisciplinary Analysis (AMMA). Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2008, 113 (D21), pp.D21105. ⟨10.1029/2008JD010327⟩. ⟨hal-00337060⟩



Les métriques sont temporairement indisponibles