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A Simulation of the Separate Climate Effects of Middle-Atmospheric and Tropospheric CO2 Doubling.
- Source :
- Journal of Climate; Jun2004, Vol. 17 Issue 12, p2352-2367, 16p, 1 Chart, 11 Graphs
- Publication Year :
- 2004
-
Abstract
- The separate climate effects of middle-atmospheric and tropospheric CO<subscript>2</subscript> doubling have been simulated and analyzed with the ECHAM middle-atmosphere climate model. To this end, the CO<subscript>2</subscript> concentration has been separately doubled in the middle-atmosphere, the troposphere, and the entire atmosphere, and the results have been compared to a control run. During NH winter, the simulated uniformly doubled CO<subscript>2</subscript> climate shows an increase of the stratospheric residual circulation, a small warming in the Arctic lower stratosphere, a weakening of the zonal winds in the Arctic middle-atmosphere, an increase of the NH midlatitude tropospheric westerlies, and a poleward shift of the SH tropospheric westerlies. The uniformly doubled CO<subscript>2</subscript> response in most regions is approximately equal to the sum of the separate responses to tropospheric and middle-atmospheric CO<subscript>2</subscript> doubling. The increase of the stratospheric residual circulation can be attributed for about two-thirds to the tropospheric CO<subscript>2</subscript> doubling and one-third to the middle-atmospheric CO<subscript>2</subscript> doubling. This increase contributes to the Arctic lower-stratospheric warming and, through the thermal wind relationship, to the weakening of the Arctic middle-atmospheric zonal wind. The increase of the tropospheric NH midlatitude westerlies can be attributed mainly to the middle-atmospheric CO<subscript>2</subscript> doubling, indicating the crucial importance of the middle-atmospheric CO<subscript>2</subscript> doubling for the tropospheric climate change. Results from an additional experiment show that the CO<subscript>2</subscript> doubling above 10 hPa, which is above the top of many current GCMs, also causes significant changes in the tropospheric climate. [ABSTRACT FROM AUTHOR]
- Subjects :
- CARBON dioxide
ATMOSPHERE
TROPOSPHERE
STRATOSPHERE
CLIMATE change
CLIMATOLOGY
Subjects
Details
- Language :
- English
- ISSN :
- 08948755
- Volume :
- 17
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Journal of Climate
- Publication Type :
- Academic Journal
- Accession number :
- 13459028
- Full Text :
- https://doi.org/10.1175/1520-0442(2004)017<2352:ASOTSC>2.0.CO;2