摘要
南极海冰的变化和全球大气环流关系密切。南极各区海冰的不同变化,对南北半球大气环流有着不同的影响。文中基于对南极海冰变化的客观分区,定义了南极海冰北界涛动指数(ASEOI),并结合中央气象台提供的南方涛动指数、北半球500 hPa和100 hPa高度场资料以及我国160站降水、温度资料,利用诊断分析方法,对ASEOI与我国夏季天气气候的关系进行了研究。研究表明:ASEOI对我国长江中下游降水及全国大部分地区温度具有指示意义。若前一年10月ASEOI偏低,则当年7月我国长江中下游降水偏多,引发洪涝灾害的可能性很大;温度场上,我国北方气温偏高,南方气温偏低,而高温往往伴随着少雨,这无疑会加剧华北本就严重的旱情。
Sea ice is an important part of climate system and its change will influence local and regional circulation, even global climate change. Recently, Arctic Oscillation （AO） and Antarctic Oscillation （AAO） and their impacts on East Asia and global climate draw more attention of meteorologists. Cheng et al. find a teetertotter characteristic of sea ice concentration between the peripheries of Ross Sea and Bellingshausen Sea, and define the differences between them as the Antarctic Sea-ice Oscillation Index （ASOI）. However, it＇s hard to define the scopes of these two regions exactly. In this study, a new index, ASEOI is built, as the difference of sea ice extent between Ross Sea Region and Antarctic Peninsula Region. Higher ASEOI represents less sea ice in Ross Sea Region and more sea ice in Antarctic Peninsula Region. Results indicate that this new index can well account for the impacts of prophasic sea-ice variations on atmospheric circulation and synoptic climate.
The correlation analysis between ASEOI and SOI indicates that lower ASEOI in the previous spring of Southern Hemisphere （SH） will cause stronger Southern Oscillation （SO） ; lower ASEOI in the previous autumn of SH will lead to weaker SO from June to September. ASEOI can be used as an indicator of precipitation in the lower and middle reaches of Yangtze River and temperature in North China and South China. Taking ASEOI in October as examples, if ASEOI in the preceding October is below normal, the precipitation in the middle and lower reaches of Yangtze River in July would be more and the flood would be easy to build there, while the temperature would be higher in most part of North China and lower in South China. As it is known, less precipitation usually comes with the hot weather, and this would undoubtedly intensify drought in North China.
This research helps the better understanding of interaction between Antarctica sea ice and atmospheric circulation and cognize the physical processes of sea-ice-air interaction in Antarctica, and offers helpful reference for further discussing the relationship between the variations of Antarctic sea ice and atmospheric circulation or synoptic climate. At the same time, it helps develop the correlative numerical simulation and seek the strong prognosis signals of Antarctica to the short-term climate influence on China.
出处
《应用气象学报》
CSCD
北大核心
2007年第4期568-572,共5页
Journal of Applied Meteorological Science
基金
国家自然科学基金项目(40575033
40333032)
国家科技支撑计划"极地科学研究"项目共同资助
关键词
南极海冰
涛动
遥相关
全球变化
Antarctic sea ice
oscillation
teleconnection
global change
