DOI: 10.1007/s00382-017-3890-8
Scopus记录号: 2-s2.0-85028762392
论文题名: Atmospheric feedbacks in North Africa from an irrigated, afforested Sahara
作者: Kemena T.P. ; Matthes K. ; Martin T. ; Wahl S. ; Oschlies A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2018
卷: 50, 期: 2018-11-12 起始页码: 4561
结束页码: 4581
语种: 英语
英文关键词: Afforestation
; Circulation
; Climate engineering
; Irrigation
; West African monsoon
英文摘要: Afforestation of the Sahara has been proposed as a climate engineering method to sequester a substantial amount of carbon dioxide, potentially effective to mitigate climate change. Earlier studies predicted changes in the atmospheric circulation system. These atmospheric feedbacks raise questions about the self-sustainability of such an intervention, but have not been investigated in detail. Here, we investigate changes in precipitation and circulation in response to Saharan large-scale afforestation and irrigation with NCAR’s CESM-WACCM Earth system model. Our model results show a Saharan temperature reduction by 6 K and weak precipitation enhancement by 267 mm/year over the Sahara. Only 26% of the evapotranspirated water re-precipitates over the Saharan Desert, considerably large amounts are advected southward to the Sahel zone and enhance the West African monsoon (WAM). Different processes cause circulation and precipitation changes over North Africa. The increase in atmospheric moisture leads to radiative cooling above the Sahara and increased high-level cloud coverage as well as atmospheric warming above the Sahel zone. Both lead to a circulation anomaly with descending air over the Sahara and ascending air over the Sahel zone. Together with changes in the meridional temperature gradient, this results in a southward shift of the inner-tropical front. The strengthening of the Tropical easterly jet and the northward displacement of the African easterly jet is associated with a northward displacement and strengthening of the WAM precipitation. Our results suggest complex atmospheric circulation feedbacks, which reduce the precipitation potential over an afforested Sahara and enhance WAM precipitation. © 2017, Springer-Verlag GmbH Germany. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109282
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Christian-Albrechts Universität zu Kiel, Kiel, Germany
Recommended Citation:
Kemena T.P.,Matthes K.,Martin T.,et al. Atmospheric feedbacks in North Africa from an irrigated, afforested Sahara[J]. Climate Dynamics,2018-01-01,50(2018-11-12)