air temperature
; anthropogenic effect
; atmospheric circulation
; data interpretation
; greenhouse gas
; low pressure system
; ozone depletion
; Southern Hemisphere
; stratosphere
; summer
; troposphere
; warming
; Antarctica
; Southern Africa
英文摘要:
The notable rise in surface air temperatures over southern Africa over the past two decades is thought to largely result from the human-induced increase in atmospheric greenhouse gas concentrations. In addition, the loss of stratospheric ozone over Antarctica is thought to have had a significant impact on tropospheric circulation, and hence climate, in the Southern Hemisphere summer, by favouring the positive phase of the Southern Annular Mode. Here, we use reanalysis data to compare the climate of southern Africa before and after the development of the large ozone hole, and investigate possible links between the development of the Antarctic ozone hole and summer warming in the region, defining 1970-1993 as the pre-ozone hole era, and 1993-2011 as the large ozone hole era. We find that the ozone-induced shift in the polarity of the Southern Annular Mode after 1993 coincided with an intensification of the Angola Low, a continental low pressure system that normally develops in austral summer and is mostly located over Angola. We show that the deepening of this low pressure system, in turn, was associated with an increase in the flux of warm surface air from the lower latitudes to southern Africa. We suggest that the recent summer warming over southern Africa is linked to these shifts in atmospheric circulation that are probably induced by Antarctic ozone loss.
Department of Geography, Bindura University of Science, B Pag 1020, Bindura, Zimbabwe; Department of Ocean Technology, Policy, and Environment, University of Tokyo, Tokyo 277-8561, Japan; International Center for Theoretical Physics (ICTP), 34151 Trieste, Italy; Research Institute for Global Change, JAMSTEC, 3173-25, Showa-machi, Japan; Application Laboratory, JAMSTEC, 3173-25, Showa-machi, Japan
Recommended Citation:
Manatsa D.,Morioka Y.,Behera S.K.,et al. Link between Antarctic ozone depletion and summer warming over southern Africa[J]. Nature Geoscience,2013-01-01,6(11)