DOI: 10.1002/jgrd.50775
论文题名: Unraveling impact factors for future changes in the Brewer-Dobson circulation
作者: Oberländer S. ; Langematz U. ; Meul S.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 18 起始页码: 10296
结束页码: 10312
语种: 英语
英文关键词: Brewer-Dobson circulation
; climate forcings
; downward control principle
; future changes
; mean age of stratospheric air
; stratosphere
Scopus关键词: Climate models
; Gravity waves
; Greenhouse gases
; Mixing
; Sea ice
; Tropics
; Brewer-Dobson circulation
; Climate forcings
; Downward control
; future changes
; Mean ages
; Upper atmosphere
; atmospheric circulation
; atmospheric pollution
; climate forcing
; climate modeling
; concentration (composition)
; greenhouse gas
; mass transfer
; mixing
; radiative transfer
; simulation
; stratosphere
; synoptic meteorology
英文摘要: Climate models project an increase in the Brewer-Dobson circulation (BDC) with increasing future greenhouse gas (GHG) concentrations. This study identifies the causes of future changes in the BDC from sensitivity simulations with the EMAC chemistry-climate model, by changing the external forcings, like GHG concentrations, sea surface temperatures (SSTs) together with sea ice concentrations, and ozone-depleting substances (ODS), separately. The particular influence of rising tropical SSTs is assessed. Contributions of different waves to changes in the residual circulation are calculated as well as changes in mean age of stratospheric air (AoA) to account for the effect of mixing processes. We find that in boreal winter the tropical upward mass flux increases by about 1%/dec in the upper and 2%/dec in the lower stratosphere until the end of the 21st century. Mean AoA decreases by up to 60 and 30 days/dec, respectively. Changes in transient planetary and synoptic waves account for the strengthening of the BDC in the lower stratosphere, whereas upper stratospheric changes are due to improved propagation properties for gravity waves in future climate. Regarding the external forcings, the radiative impact of rising GHG concentrations is detected to affect upper stratospheric layers only, whereas lower stratospheric signals are almost entirely due to rising SSTs. Changes in tropical SSTs influence not only the shallow but also the deep branch of the BDC as confirmed from both changes in residual circulation and mixing. Declining ODS will slightly counteract the BDC increase in the Southern Hemisphere. Key Points Separation of impact from GHGs, ODS, SSTs to future strengthening of the BDCTropical SSTs are important contributor in lower and upper stratosphereMain drivers are transient planetary as well as orographic gravity waves ©2013. American Geophysical Union. All Rights Reserved. 资助项目: LA 1025/13-1
; LA 1025/14-1
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63304
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
There are no files associated with this item.
作者单位: Institut für Meteorologie, Freie Universität Berlin, Carl-Heinrich-Becker Weg 6-10, 12165 Berlin, Germany
Recommended Citation:
Oberländer S.,Langematz U.,Meul S.. Unraveling impact factors for future changes in the Brewer-Dobson circulation[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(18)