DOI: 10.5194/cp-12-961-2016
Scopus记录号: 2-s2.0-84966356275
论文题名: The influence of volcanic eruptions on the climate of tropical South America during the last millennium in an isotope-enabled general circulation model
作者: Colose C.M. ; LeGrande A.N. ; Vuille M.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2016
卷: 12, 期: 4 起始页码: 961
结束页码: 979
语种: 英语
Scopus关键词: climate change
; climate modeling
; El Nino-Southern Oscillation
; general circulation model
; hydrological cycle
; intertropical convergence zone
; isotopic composition
; oxygen isotope
; paleoclimate
; proxy climate record
; tropical environment
; uncertainty analysis
; volcanic eruption
; Amazonia
英文摘要: Currently, little is known on how volcanic eruptions impact large-scale climate phenomena such as South American paleo-Intertropical Convergence Zone (ITCZ) position and summer monsoon behavior. In this paper, an analysis of observations and model simulations is employed to assess the influence of large volcanic eruptions on the climate of tropical South America. This problem is first considered for historically recent volcanic episodes for which more observations are available but where fewer events exist and the confounding effects of El Niño-Southern Oscillation (ENSO) lead to inconclusive interpretation of the impact of volcanic eruptions at the continental scale. Therefore, we also examine a greater number of reconstructed volcanic events for the period 850 CE to present that are incorporated into the NASA GISS ModelE2-R simulation of the last millennium. An advantage of this model is its ability to explicitly track water isotopologues throughout the hydrologic cycle and simulating the isotopic imprint following a large eruption. This effectively removes a degree of uncertainty associated with error-prone conversion of isotopic signals into climate variables, and allows for a direct comparison between GISS simulations and paleoclimate proxy records. Our analysis reveals that both precipitation and oxygen isotope variability respond with a distinct seasonal and spatial structure across tropical South America following an eruption. During austral winter, the heavy oxygen isotope in precipitation is enriched, likely due to reduced moisture convergence in the ITCZ domain and reduced rainfall over northern South America. During austral summer, however, more negative values of the precipitation isotopic composition are simulated over Amazonia, despite reductions in rainfall, suggesting that the isotopic response is not a simple function of the "amount effect". During the South American monsoon season, the amplitude of the temperature response to volcanic forcing is larger than the rather weak and spatially less coherent precipitation signal, complicating the isotopic response to changes in the hydrologic cycle. © Author(s) 2016. 资助项目: NSF, National Stroke Foundation
; NSF, National Stroke Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49026
Appears in Collections: 气候变化与战略
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Recommended Citation:
Colose C.M.,LeGrande A.N.,Vuille M.. The influence of volcanic eruptions on the climate of tropical South America during the last millennium in an isotope-enabled general circulation model[J]. Climate of the Past,2016-01-01,12(4)