DOI: 10.1175/JCLI-D-15-0599.1
Scopus记录号: 2-s2.0-84983509290
论文题名: Regional influences of natural external forcings on the transition from the medieval climate anomaly to the little ice age
作者: Andres H.J. ; Peltier W.R.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2016
卷: 29, 期: 16 起始页码: 5779
结束页码: 5800
语种: 英语
Scopus关键词: Atmospheric temperature
; Climate change
; Gas emissions
; Glacial geology
; Greenhouse gases
; Sea ice
; Spectral resolution
; Volcanoes
; Background conditions
; Medieval climate anomalies
; Medieval Climate Anomaly (MCA)
; Ocean heat content
; Sea ice concentration
; Surface air temperatures
; Temperature reduction
; Total solar irradiance
; Ice
英文摘要: Reconstructions of historical climate changes indicate that surface air temperatures decreased over the preindustrial last millennium. Conflicting explanations have been proposed for the cause of the transition from the Medieval Climate Anomaly (MCA) in the early part of the last millennium to the Little Ice Age (LIA) near its end. The possible causes include volcanic emissions, total solar irradiance (TSI) variations, greenhouse gas concentration fluctuations, and orbital forcing variations. In the present paper, it is demonstrated that all of these climate forcings contribute significantly to simulated surface air temperature (SAT) and sea ice concentration changes over this period. On the other hand, simulated ocean heat content appears to respond significantly only to volcanic and TSI variations. In model simulations at T85 spectral resolution, TSI reductions and volcanic emissions together generate significant increases in sea ice extent in the Barents Sea, which is found to be responsible for most of the temperature reductions over northwestern Europe. TSI appears less important to Arctic sea ice and SAT changes in simulations at T42 spectral resolution, which are weaker than at T85 resolution. Such resolution dependence is attributed to differences in background conditions in the responses to these external climate forcings. Nonlinearities in the forcing responses and sensitivities to background conditions challenge the assumption that sensitivity tests for given forcings can be run independently. Additionally, it is demonstrated that an ensemble of model simulations is required to isolate forcing responses even over a period as long as the last millennium. © 2016 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50216
Appears in Collections: 气候变化事实与影响
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作者单位: University of Toronto, Toronto, ON, Canada
Recommended Citation:
Andres H.J.,Peltier W.R.. Regional influences of natural external forcings on the transition from the medieval climate anomaly to the little ice age[J]. Journal of Climate,2016-01-01,29(16)