DOI: 10.1175/JCLI-D-14-00639.1
Scopus记录号: 2-s2.0-84942874336
论文题名: The influence of orbital forcing of tropical insolation on the climate and isotopic composition of precipitation in South America
作者: Liu X. ; Battisti D.S.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 12 起始页码: 4841
结束页码: 4862
语种: 英语
Scopus关键词: Atmospheric thermodynamics
; Climate models
; Dynamics
; Earth atmosphere
; Incident solar radiation
; Isotopes
; Mechanical waves
; Solar radiation
; Atmospheric circulation
; Atmospheric general circulation models
; Hydrologic cycles
; Intertropical convergence zone
; Isotopic composition
; Northeastern Brazil
; Paleoclimates
; South atlantic convergence zones
; Climate change
; atmospheric circulation
; atmospheric dynamics
; climate change
; climate modeling
; hydrological cycle
; intertropical convergence zone
; isotopic composition
; orbital forcing
; paleoclimate
; precipitation (climatology)
; precipitation intensity
; Rossby wave
; Africa
; Andes
; Atlantic Ocean
; Atlantic Ocean (South)
; Brazil
英文摘要: The δ18Oof calcite (δ18Oc ) in speleothems from South America is fairly well correlated with austral summer [December-February (DJF)] insolation, indicating the role of orbitally paced changes in insolation in changing the climate of South America. Using an isotope-enabled atmospheric general circulation model (ECHAM4.6) coupled to a slab ocean model, the authors study how orbitally paced variations in insolation change climate and the isotopic composition of precipitation (δ18Op ) of South America. Compared with times of high summertime insolation, times of low insolation feature (i) a decrease in precipitation inland of tropical South America as a result of an anomalous cooling of the South American continent and hence a weakening of the South American summer monsoon and (ii) an increase in precipitation in eastern Brazil that is associated with the intensification and southward movement of the Atlantic intertropical convergence zone, which is caused by the strengthening of African winter monsoon that is induced by the anomalous cooling of northern Africa. Finally, reduced DJF insolation over southern Africa causes cooling and the generation of a tropically trapped Rossby wave that intensifies and shifts the South Atlantic convergence zone northward. In times of low insolation, δ18Op increases in the northern Andes and decreases in northeastern Brazil, consistent with the pattern of δ18Oc changes seen in speleothems. Further analysis shows that the decrease in δ18Op in northeastern Brazil is due to change in the intensity of precipitation, while the increase in the northern Andes reflects a change in the seasonality of precipitation and in the isotopic composition of vapor that forms the condensates. © 2015 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50730
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States
Recommended Citation:
Liu X.,Battisti D.S.. The influence of orbital forcing of tropical insolation on the climate and isotopic composition of precipitation in South America[J]. Journal of Climate,2015-01-01,28(12)