DOI: 10.1007/s00382-017-3820-9
Scopus记录号: 2-s2.0-85025824968
论文题名: Impact of a shallow groundwater table on the global water cycle in the IPSL land–atmosphere coupled model
作者: Wang F. ; Ducharne A. ; Cheruy F. ; Lo M.-H. ; Grandpeix J.-Y.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2018
卷: 50, 期: 2018-09-10 起始页码: 3505
结束页码: 3522
语种: 英语
英文关键词: Groundwater table
; IPSL-CM
; Land–atmosphere
; Near surface climate
; West African Monsoon
Scopus关键词: atmosphere-ocean coupling
; climate modeling
; evapotranspiration
; groundwater
; monsoon
; shallow water
; temperature gradient
; water table
; water vapor
英文摘要: The main objective of the present work is to study the impacts of water table depth on the near surface climate and the physical mechanisms responsible for these impacts through the analysis of land–atmosphere coupled numerical simulations. The analysis is performed with the LMDZ (standard physics) and ORCHIDEE models, which are the atmosphere-land components of the Institut Pierre Simon Laplace (IPSL) Climate Model. The results of sensitivity experiments with groundwater tables (WT) prescribed at depths of 1 m (WTD1) and 2 m (WTD2) are compared to the results of a reference simulation with free drainage from an unsaturated 2 m soil (REF). The response of the atmosphere to the prescribed WT is mostly concentrated over land, and the largest differences in precipitation and evaporation are found between REF and WTD1. Saturating the bottom half of the soil in WTD1 induces a systematic increase of soil moisture across the continents. Evapotranspiration (ET) increases over water-limited regimes due to increased soil moisture, but it decreases over energy-limited regimes due to the decrease in downwelling radiation and the increase in cloud cover. The tropical (25°S–25°N) and mid-latitude areas (25°N–60°N and 25°S–60°S) are significantly impacted by the WT, showing a decrease in air temperature (−0.5 K over mid-latitudes and −1 K over tropics) and an increase in precipitation. The latter can be explained by more vigorous updrafts due to an increased meridional temperature gradient between the equator and higher latitudes, which transports more water vapour upward, causing a positive precipitation change in the ascending branch. Over the West African Monsoon and Australian Monsoon regions, the precipitation changes in both intensity (increases) and location (poleward). The more intense convection and the change of the large-scale dynamics are responsible for this change. Transition zones, such as the Mediterranean area and central North America, are also impacted, with strengthened convection resulting from increased ET. © 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/109343
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: Laboratoire de Météorologie Dynamique, IPSL, CNRS, Sorbonne Universités, UPMC, Paris, 75005, France; Sorbonne Universités, UPMC, CNRS, EPHE, UMR 7619 METIS, 4 place Jussieu, Paris, 75005, France; Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan
Recommended Citation:
Wang F.,Ducharne A.,Cheruy F.,et al. Impact of a shallow groundwater table on the global water cycle in the IPSL land–atmosphere coupled model[J]. Climate Dynamics,2018-01-01,50(2018-09-10)