气候变化领域集成服务门户(CCPortal): Anthropogenic and natural contributions to the lengthening of the southern hemisphere summer season

CCPortal

DOI	10.1175/JCLI-D-20-0084.1
	Anthropogenic and natural contributions to the lengthening of the southern hemisphere summer season
	Weller E.; Park B.-J.; Min S.-K.
发表日期	2020
ISSN	0894-8755
起始页码	10539
结束页码	10553
卷号	33 期号:24
英文摘要	This study provides the first quantitative assessment of observed long-term changes in summer-season timing and length in the Southern Hemisphere (SH) and its subregions over the past 60 years, enabling a global completeness by complementing such characteristics previously reported for the Northern Hemisphere (NH). Using an objective algorithm that is based on temperature indices, relative measures of summer onset, withdrawal, and duration are determined at each land location over the period 1953-2012. Significant widespread summer-season lengthening, due to earlier onset and delayed withdrawal, has occurred across the SH, a longer period for extreme heat-wave events and wildfires to potentially occur. The asymmetric magnitude (onset vs withdrawal) in summer-season lengthening is slightly less over the SH than over the NH. Contributions of anthropogenic and natural factors to the observed trends in summer-season characteristics were investigated using phase 5 of the Coupled Model Intercomparison Project (CMIP5) multimodel simulations integrated with observed external forcings [anthropogenic plus natural (ALL)], greenhouse gas forcing only (GHG), and natural forcing only [solar and volcanic activities (NAT)]. Overall, consistent with the NH, increased greenhouse gases were the main cause of observed changes in the SH, with negligible contribution from other external forcings. ALL and GHG simulations also reproduced a slight tendency for earlier summer onset to contribute more to summer lengthening. Proportions of observed regional trends in summer-season indices attributable to trends in long-term internal variability in the SH, namely, the interdecadal Pacific oscillation (IPO) and southern annular mode (SAM), suggests such variability can only explain up to ~12%, supporting the dominant role of greenhouse gas forcing. © 2020 American Meteorological Society.
英文关键词	Climate models; Climatology; Coupled Model Intercomparison Project; Greenhouse-gas forcing; Inter-decadal pacific oscillations; Internal variability; Multi-Model Simulations; Northern hemisphere; Quantitative assessments; Southern Annular Mode; Greenhouse gases; algorithm; climate change; climate modeling; extreme event; greenhouse gas; heat wave; human activity; seasonal variation; Southern Hemisphere; summer
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171032
作者单位	School of Environment, University of Auckland, Auckland, New Zealand; Division of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, South Korea
推荐引用方式 GB/T 7714	Weller E.,Park B.-J.,Min S.-K.. Anthropogenic and natural contributions to the lengthening of the southern hemisphere summer season[J],2020,33(24).
APA	Weller E.,Park B.-J.,&Min S.-K..(2020).Anthropogenic and natural contributions to the lengthening of the southern hemisphere summer season.Journal of Climate,33(24).
MLA	Weller E.,et al."Anthropogenic and natural contributions to the lengthening of the southern hemisphere summer season".Journal of Climate 33.24(2020).