DOI: 10.1007/s00531-014-1102-x
Scopus记录号: 2-s2.0-84904071709
论文题名: The East African Rift System and the impact of orographic changes on regional climate and the resulting aridification
作者: Sommerfeld A. ; Prömmel K. ; Cubasch U.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2016
卷: 105, 期: 6 起始页码: 1779
结束页码: 1794
语种: 英语
英文关键词: Aridification
; Climate simulation
; East African Rift System
; Orographic forcing
; Paleo-climate
Scopus关键词: aridification
; climate modeling
; computer simulation
; Neogene
; orographic effect
; orography
; paleoclimate
; regional climate
; spatial resolution
; East African Lakes
; East African Rift
; Lake Victoria
英文摘要: Several proxy data indicate an aridification of the East African climate during the Neogene, which might be influenced by the orographic changes of the East African Rift System (EARS) induced by tectonic forcing during the last 20 million years. To investigate the impact of the orography and especially of the rifts, the regional climate model CCLM is used, covering the EARS with Lake Victoria in the centre of the model domain. CCLM is driven by the ERA-Interim reanalysis and applied with a double-nesting method resulting in a very high spatial resolution of 7 km. The resolution clearly shows the shoulders and rifts of the western and eastern branch of the EARS and the Rwenzoris within the western branch. To analyse the orographic influence on climate, a new technique of modifying the orography is used in this sensitivity study. The shoulders of the branches are lowered and the rifts are elevated, resulting in a smoothed orography structure with less altitude difference between the shoulders and rifts. The changes in 2 m-temperature are very local and associated with the changes in the orography. The vertically integrated moisture transport is characterised by less vortices, and its zonal component is increased over the branches. The resulting amount of precipitation is mainly decreased west of the western branch and increased in the rift of the western branch. In the eastern branch, however, the changes in the amount of precipitation are not significant. The changes in the precipitation and temperature patterns lead to a shift of biomes towards a vegetation coverage characterised by more humid conditions in the northern part of the model domain and more arid conditions in the South. Thus, the aridification found in the proxy data can be attributed to the orographic changes of the rifts only in the northern model domain. © 2014, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904071709&doi=10.1007%2fs00531-014-1102-x&partnerID=40&md5=cc5815909d2fcd944d640c0c295ea04a
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70133
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Institute of Meteorology, Freie Universität Berlin, Carl-Heinrich-Becker-Weg 6-10, Berlin, Germany; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Research Unit Potsdam, Postfach 600149, Potsdam, Germany
Recommended Citation:
Sommerfeld A.,Prömmel K.,Cubasch U.. The East African Rift System and the impact of orographic changes on regional climate and the resulting aridification[J]. International Journal of Earth Sciences,2016-01-01,105(6)