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1.
我国西南地区秋季降水年际变化的空间差异及其成因 总被引：3，自引：0，他引：3
使用1980～2010年全国站点降水资料、ERA-Interim再分析环流资料、哈德莱海表温度资料,运用聚类分析和旋转经验正交函数分解,对西南地区的秋季降水按照其年际变化规律进行分区,进而分析影响各区域降水变化的物理过程和机理。结果表明:西南地区被分为东、西两个区域。西南东、西区域秋季降水的年际变化、显著周期、旱涝异常年份、相关的环流系统都有明显差异。西南东部秋季降水主要与热带海温异常有关,受低纬度环流影响。当赤道东太平洋为暖海温异常,热带印度洋为西正东负的偶极子型海温异常时,分别激发出西北太平洋反气旋和孟加拉反气旋,共同向西南东部输送水汽,造成西南东部降水偏多。西南西部降水在秋季三个月份与不同的环流形势对应:9月降水由中南半岛反气旋输送的暖湿气流决定;10月降水受高原以东反气旋环流和孟加拉湾低槽共同影响;11月降水主要受中高纬环流异常的影响,与斯堪的纳维亚遥相关存在显著负相关。 相似文献
2.
ENSO对印度洋偶极子与中国秋季降水关系的影响 总被引：14，自引：3，他引：14
利用1950--1999年Hadley中心全球海温资料、NCEP／NCAR再分析资料和中国气象局整编的160站降水资料，通过讨论印度洋偶极子（IOD）独立发生时及IOD与ENSO联合发生时中国秋季降水的差异，研究了ENSO对IOD与中国秋季降水关系的影响。结果表明：仅有IOD发生时，其正位相年使得中国西南地区和黄河流域的秋季降水出现正异常，而当IOD与ENSO伴随出现时，IOD正位相年和E1Nino使得中国西南地区秋季降水正异常区域维持并向东扩展，还使得黄河流域秋季降水转为负异常。此外分析了ENSO改变IOD与中国秋季降水关系的环流成因。 相似文献
3.
前期热带太平洋、印度洋海温异常对长江流域及以南地区6月降水的影响 总被引：10，自引：4，他引：10
利用NCEP/NCAR提供的1951—2000年全球月平均海表温度距平资料及中国160个测站的月降水资料,采用相关关系分析、合成分析方法,研究了前期热带太平洋、印度洋海温异常对长江流域及以南地区6月降水的影响。结果表明:(1)Nino3指数与印度洋偶极子指数(IODI)有明显的季节变化,且两者同期相关关系随季节不同,以秋季的相关关系最好,相关系数达0.523,并且这时两种指数的强度也较大。作秋季ENSO和印度洋偶极子同时发生年至次年6月的时间序列,发现两事件存在2月左右的位相差,IODI在9—10月达到峰值,Nino3指数在12月达到峰值。说明在相关最好的秋季两事件并不是完全同步的;(2)前期秋季Nino3指数、印度洋偶极子指数及新定义的同时考虑两种指数的一个综合指数—IODN3这3种指数与中国6月降水的相关系数分布有相似特征,主要表现为相关显著区都在长江流域及以南地区。3种指数与降水的相关中,以IODN3与降水相关关系最为显著,显著区范围也最大;(3)前期秋季El Nio和印度洋偶极子正位相同时发生年6月的500 hPa位势高度、垂直速度、水汽输送等异常分布与其前期秋季反位相年6月的异常分布有相反的特征,表明海温异常对长江流域及以南地区降水有重要影响,对应该地区6月降水偏多或偏少;(4)前期秋季El Nio和印度洋偶极子正位相同时发生使菲律宾反气旋加强和维持,形成有利于降水的环流形势。 相似文献
4.
印度洋偶极子和华西秋雨的关系 总被引：6，自引：0，他引：6
《高原气象》2015,(4)
利用统计方法对印度洋偶极子(Indian Ocean Dipole,IOD)与华西秋雨的关系进行分析。结果发现:(1)相对于IOD的季节锁相特征,华西秋雨与印度洋偶极子指数(Indian Ocean Dipole Index,IODI)相关性也呈现相应的变化特征:春、夏季正相关发展、范围扩大;秋季稳定且正相关性较高,与夏季时滞相关较为一致;前期冬季减弱并呈反相关关系。(2)对印度洋偶极子时期异常环流场、水汽场以及射出长波辐射(Outgoing Longwave Radiation,OLR)场特征分析发现,IOD正位相年,500 h Pa高度场距平在冬、春季为负异常,春、秋季西太平洋副热带高压偏强、偏北,且夏季华西区域受中层异常浅槽的西南气流影响,850 h Pa经向风合成在冬、春季以负异常为主,夏、秋季转为正异常,且华西区域秋季为异常气旋性环流控制,赤道印度洋低空东风异常,这些异常环流都利于华西区域降水偏多,并对偶极子的延续起到作用。(3)正位相年,冬、春季华西大部区域为水汽辐散区,夏、秋季四川东北部及黔渝大部为水汽辐合区,水汽输送依靠孟湾西南气流和西太平洋副热带高压外围的偏东气流完成。(4)对应于印度洋海温正(负)异常,秋季华西区域上空的热状况异常分布将使其大气对流增强(减弱)。因此,夏季IOD异常位相为华西秋雨预报提供了一个有用的前期信号,而秋季IOD正位相则对华西秋雨的发生发展起到较好的延续作用。 相似文献
5.
基于HadISST逐月海温数据,对热带印度洋-太平洋海区海温场主模态及其组合进行了研究。结果表明：三种类型的El Niño事件中,东部型（EP）和对称中部型（CPⅠ）发展年,热带印度洋东部及海洋性大陆降水为负异常,印-太海区Walker环流减弱,赤道印度洋为东风异常,根据Bjerknes反馈,东印度洋海温负异常,易形成正位相印度洋偶极子（Positive Indian Ocean Dipole,PIOD）事件;而非对称中部型（CPⅡ）与印度洋偶极子（Indian Ocean Dipole,IOD）事件无相关性。进一步对印-太海区海温场主模态及其组合与中国南部秋季降水异常的关系进行分析发现,独立EP型、独立CPⅠ型、EP与PIOD组合型及CPⅠ与PIOD组合型四种模态下,在赤道印度洋及热带太平洋暖湿气流的作用下,中国东南部秋季降水呈正异常,其中独立EP型、独立CPⅠ型和CPⅠ与PIOD组合型对中国东南部的局地水汽净输入以自西向东的纬向贡献为主,而EP与PIOD组合型由于西太平洋副热带高压的异常西伸,水汽沿副高西南边缘向北输送进入中国东南部,对中国东南部的局地水汽净输入以经向贡献为主。CPⅡ型El Niño事件发展年,中国南部大部分地区秋季降水异常偏少;独立PIOD事件发展年,中国西南部地区秋季降水表现为正异常,而东南部呈负异常。 相似文献
6.
印度洋偶极子对东亚季风区天气气候的影响 总被引：18，自引：1，他引：17
利用NCEP/NCAR 40年再分析资料和中国科学院大气物理研究所的IAPAGCM-Ⅱ大气环流模式,分析和模拟了印度洋偶极子对东亚季风区天气气候的影响.结果表明,印度洋偶极子对东亚季风区天气气候,特别是夏季,影响显著.印度洋正偶极子位相期间,东亚地区的西南季风爆发偏晚,强度增强,我国大陆降水增多;而印度洋负偶极子位相期间,东亚地区的西南季风爆发偏早,强度减弱,我国的东南部地区有丰富的降水. 相似文献
7.
赤道东太平洋海温异常期间印度洋偶极子对东亚季风区影响的数值模拟 总被引：6，自引：7，他引：6
利用中科院大气所的IAP AGCM-Ⅱ大气环流模式，模拟了在存在和没有赤道东太平洋海温异常影响下，印度洋偶极子对东亚季风区天气气候的影响。结果表明：后者东亚地区西南季风的爆发偏晚，南海夏季风增强，此时我国大陆降水偏多；而前者西南季风的爆发将更偏晚，南海夏季风减弱，此时华北降水偏少；赤道东太平洋海温异常和印度洋偶极子有协同作用。 相似文献
8.
2018年秋季我国气候异常及成因分析 总被引：2，自引：2，他引：0
2018年秋季我国气候异常特征总体表现为：气温呈“东高西低”的分布;东部降水呈“南北多、中间少”的分布,其中内蒙古中东部、东北、江南南部和华南大部地区降水异常偏多,而华北至江南北部降水异常偏少,且江南和西南地区降水出现明显的季节内反向分布转变特征。异常成因分析表明,秋季欧亚中高纬度槽脊活动频繁,冷空气活跃,西太平洋副热带高压较常年同期偏强偏西,脊线季节内南北波动较大,西南水汽输送偏强,导致我国东部降水南北多、中间少。进一步研究表明,海温异常是影响2018年秋季我国气候异常的最主要外强迫因子,季节内El Ni〖AKn~D〗o由中部型向东部型发展,热带印度洋海温偶极子正位相持续,副热带南印度洋偶极子正位相发展。秋季后期El Ni〖AKn~D〗o影响增强,东亚副热带大气环流发生明显的季节内响应。因此,El Ni〖AKn~D〗o和印度洋海温的演变及其对东亚环流的影响,加上欧亚中高纬环流异常的季节内调整,二者共同导致了我国南方地区降水出现明显的东西反向的季节内变化。 相似文献
9.
利用1961-2011年NCEP/NCAR再分析资料和黄河流域54站降水资料,通过讨论印度洋偶极子IOD独立发生时及IOD与ENSO联合发生时黄河流域秋季降水的差异,研究了秋季降水及环流对ENSO和IOD的响应情况.结果表明:1)仅有IOD发生时,其正位相年使得黄河流域的秋季降水相应为正异常.2)当IOD与ENSO伴随出现时,无论IOD是正位相年还是负位相年,只要和El Nino同时发生,黄河流域秋季降水都表现为负异常;和La Ni-na同时发生时,黄河流域秋季降水都表现为正异常.有无ENSO发生,IOD与秋季降水的关系有很大差异.3)欧亚中纬度地区500 hPa高度东高西低距平场形势和850 hPa黄河流域中下游南风距平异常,是黄河流域秋季降水正异常的主要环流成因.4)依据秋季海温与夏季海温相关性,可以把夏季ENSO和IOD异常信号特征作为先兆信号之一来预测秋季降水趋势. 相似文献
10.
两类厄尔尼诺事件发展年秋季印度洋海温异常特征对比 总被引：6，自引：1，他引：5
基于1951—2010年逐月海气多要素观测资料,对比分析了两类厄尔尼诺事件发展年秋季印度洋的海温异常及大气响应特征,探讨了印度洋偶极子的发生与两类厄尔尼诺事件特征的可能联系。结果表明,两类厄尔尼诺事件的发展年均会出现印度洋偶极子,但出现的概率不同:大多数东部型厄尔尼诺事件都会伴有正位相印度洋偶极子发生;而仅一半的中部型厄尔尼诺事件期间会出现正位相印度洋偶极子的异常海温型,且强度较弱。从印度洋偶极子与两类厄尔尼诺事件的物理联系上看,东部型厄尔尼诺事件期间,印度洋偶极子的发生与其强度联系密切:印度洋偶极子发生在东部型厄尔尼诺事件较强期间,两者通过海洋大陆的异常强下沉运动及大范围负异常降水相联系;东部型厄尔尼诺事件偏弱时并无印度洋偶极子出现,海洋大陆异常下沉运动及负异常降水很弱。然而,中部型厄尔尼诺事件期间印度洋偶极子的发生与其强度并无显著的关系,而与太平洋高海温区的位置存在一定的可能联系:在有印度洋偶极子发生的中部型厄尔尼诺事件发展年秋季,热带太平洋异常高海温区的位置相对偏东,海洋大陆出现显著下沉运动和大范围负异常降水,热带东印度洋为大范围强异常东风控制;但无印度洋偶极子发生的中部型厄尔尼诺事件时,热带太平洋高海温区位置相对偏西,极弱的海洋大陆下沉支对热带印度洋异常海温作用非常有限。 相似文献
11.
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
12.
Fei LIU Chen XING Jinbao LI Bin WANG Jing CHAI Chaochao GAO Gang HUANG Jian LIU Deliang CHEN 《大气科学进展》2020,37(7):663-670
正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment. 相似文献
13.
Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 相似文献
14.
Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d. 相似文献
15.
Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region. 相似文献
16.
Yuepeng PAN Mengna GU Yuexin HE Dianming WU Chunyan LIU Linlin SONG Shili TIAN Xuemei Lü Yang SUN Tao SONG Wendell W. WALTERS Xuejun LIU Nicholas A. MARTIN Qianqian ZHANG Yunting FANG Valerio FERRACCI Yuesi WANG 《大气科学进展》2020,37(9):933-938
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on 相似文献
17.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter. 相似文献
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Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings 
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下载免费PDF全文 正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any 相似文献
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《大气科学进展》2014,(6)
正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang; 相似文献