两类ENSO对中国北方冬季平均气温和极端低温的不同影响

发布时间：2018-01-03 23:18

本文关键词：两类ENSO对中国北方冬季平均气温和极端低温的不同影响　出处：《气象学报》2017年04期 　论文类型：期刊论文

【摘要】：利用1961—2012年观测、再分析资料以及全球大气环流模式数值试验,探讨了中国北方冬季平均气温对于不同类型(即东部型和中部型)ENSO事件的气候响应,并分析了不同类型ENSO对极端低温事件的可能影响,重点关注了北大西洋涛动(NAO)在其中的桥梁作用。结果表明,ENSO信号能通过调制北大西洋地区的大气环流改变欧亚中高纬度地区的纬向温度平流输送和西伯利亚高压的强度,进而影响中国北方冬季气温,由于不同类型ENSO事件海温分布的差异,这种影响具有明显的非线性特征。在两类厄尔尼诺和东部型拉尼娜事件冬季,北大西洋涛动均呈现负位相,不利于北大西洋的暖湿空气向欧亚大陆输送,西伯利亚高压偏强,因而中国北方地区较气候态偏冷。中部型厄尔尼诺和东部型拉尼娜事件冬季气温负异常的显著区域分别位于东北大范围地区、内蒙古河套附近;东部型厄尔尼诺事件冬季显著的冷异常信号仅局限于黑龙江北部与大兴安岭地区;而中部型拉尼娜事件冬季虽伴随北大西洋涛动正位相,但其空间结构向西偏移,对下游中国北方地区气温的直接影响并不显著,可能受局地信号干扰较大。数值试验再现了北大西洋涛动以及中国北方冬季气温对不同类型ENSO的响应,进一步佐证了上述结论。此外,两类厄尔尼诺事件冬季中国东北地区日平均气温容易偏低,极端低温事件的发生频次增多;而两类拉尼娜事件对极端低温的影响较弱。
[Abstract]:Using 1961-2012 observations, reanalysis data and numerical experiments of the global general circulation model (GCM). The climatic response of winter mean temperature to different types of ENSO events in northern China is discussed, and the possible effects of different types of ENSO on extreme low temperature events are analyzed. The bridge action of NAO) is focused on. The results show that NAO plays an important role in this process. The ENSO signal can change the intensity of the latitudinal temperature advection and Siberian high in the middle and high latitudes of Eurasia by modulating the atmospheric circulation in the North Atlantic region, thus affecting the winter temperature in northern China. Due to the difference of SST distribution in different types of ENSO events, this effect has obvious nonlinear characteristics. In winter, the North Atlantic Oscillation (NAO) presents a negative phase in the winter of two types of El Nino and East-type La Nina events. It is not conducive to the transfer of warm and wet air from the North Atlantic to Eurasia, and the Siberian high is relatively strong. As a result, the northern part of China is colder than the climate. The significant regions of the negative winter temperature anomalies of the central El Nino event and the eastern La Nina event are located in a large area of Northeast China and near the Hetao of Inner Mongolia, respectively. The significant cold anomaly of the eastern El Nino event in winter is confined to the northern Heilongjiang and Daxing'anling regions. Although the central La Nina event is accompanied by the North Atlantic Oscillation positive phase in winter, its spatial structure shifts westward, and the direct effect on the temperature in the north of China is not significant. The response of North Atlantic Oscillation (NAO) and winter air temperature in northern China to different types of ENSO is reproduced by numerical experiments, which further supports the above conclusions. In winter, the average daily temperature of the two kinds of El Nino events in Northeast China tends to be low, and the frequency of extreme low temperature events increases. However, the two types of La Nina events have a weak effect on extreme low temperature.
【作者单位】：南京信息工程大学气象灾害教育部重点实验室气候与环境变化国际合作联合实验室气象灾害预报预警与评估协同创新中心;
【基金】：全球变化与海气相互作用专项(GASI-IPOVAI-03) 国家自然科学基金项目(41475086、41675073) 江苏省六大人才高峰 333高层次人才工程优势学科建设工程(PAPD)项目
【分类号】：P423;P732
【正文快照】： 汪子琪张文君耿新WANG Ziqi ZHANG Wenjun GENG Xin南京信息工程大学气象灾害教育部重点实验室,气候与环境变化国际合作联合实验室,气象灾害预报预警与评估协同创新中心,南京,210044Key Laboratory of Meteorological Disaster of Ministry of Education,Joint International

【相似文献】