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1.
南海季风爆发期间大气环流结构与对流热量、水汽输送特征 总被引：1，自引：0，他引：1
利用中国南海季风试验(SCSMEX)区1998年5～6月"科学1号"和"实验3号"观测船得到的一天4次加密探空资料,重点分析了南海北部地区(15～25°N,108～122°E)夏季风爆发前后大气环流的动力、热力和湿度场分布与海洋对流热量和水汽输送特征.结果表明,南海北部季风爆发前后的大气动力场、温湿场出现快速而明显的变化.季风爆发前,南海北部地区高层辐合、低层辐散,以下沉气流为主;季风爆发后,在200 hPa左右高层辐散,而在900～950 hPa左右低层辐合,并出现强上升气流.这种动力场的显著变化引起温度、湿度场的改变,直接导致南海对流的快速发展,对流活动伴随着剧烈的热量和水汽垂直输送和转化. 相似文献
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季节转换期间副热带高压带形态变异及其机制的研究Ⅱ:亚洲季风区季节转换指数 总被引：14，自引：3，他引：14
在“季节转换期间副热带高压带形态变异及其机制的研究Ⅰ :副热带高压结构气候学特征研究”的基础上 ,进一步讨论亚洲夏季风爆发与当地对流层中上层东西向暖脊的经向位置变化关系。亚洲夏季风相继在孟加拉湾、南海和南亚爆发期间 ,除了对流层高、低空风场及深对流活动在季风爆发前后具有反相的变化以外 ,副热带高压脊面附近大气经向温度梯度亦具有明显的反相特征。对流层中上层 (2 0 0～ 5 0 0hPa)脊面附近建立的北暖南冷的温度结构 ,能够反映亚洲各季风区夏季风爆发共同的本质特征 ,根据季节转换的热力学基础 ,指出对流层中上层经向温度梯度作为度量季风爆发的指标是合理可行的。文中提出了以副热带高压脊面附近对流层中上层大气经向温度梯度作为表征季节转换的指数 ,给出了确定季节转换开始日期的具体定义以及历年季节转换日期序列 ,同时给出由85 0hPa纬向风和OLR表征的季风爆发日期序列。相关分析表明 ,85 0hPa纬向风只是个区域性指标 ,而南北温度梯度具有一定的普适性 相似文献
3.
大气环流的季节突变与季风的建立Ⅱ.个别年份南海夏季风的情况 总被引：4，自引：0，他引：4
将流的标准化变差度概念应用到各年南海夏季风建立研究中去,并用其作为大气环流调整的客观定量指标.用该指标定义的南海夏季风建立的预兆日期与用传统天气气候学方法确定的南海夏季风的来临日期,在绝大多数具体年份两者均很接近,故可作南海夏季风建立的先兆指标.但有一些年份,南海季风的建立不伴随着低空环流的突变过程,两种方法都可能不准确,可靠的方法也许是用场相似度作指标.此外,南海夏季风建立前,对流层顶和平流层下层就出现了环流调整,该调整为南海夏季风建立打下基础,而南海夏季风爆发则表现为低空环流的大调整.南海夏季风的爆发是高、低空全球大气环流发生显著调整的结果,并非限于南海范围局部,南海夏季风建立不能看作是发生在南海的局部现象. 相似文献
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5.
南海夏季风爆发机制的数值实验研究 总被引：2，自引：0，他引：2
通过3个数值实验和对1998年及1996年南海夏季风爆发的对比分析以及多年资料统计研究发现,南海夏季风何时爆发与南海局部地区的海温高低和南海经度上南北海温差异的大小关系不密切,主要决定于南海及其周围大范围地区的环流形势。南海季风爆发前10天内,其环流特征是低层850hPa上,西太平洋副热带高压脊经菲律宾西伸控制南海,南亚至东南亚为宽广的低槽区所控制,高空200hPa上,南亚高压位于阿拉伯海至南海一带,中心位于孟加拉湾东侧和中南半岛西侧的低纬地区,广大北方为西风气流所控制。 相似文献
6.
大气环流的季节突变与季风的建立II·个别年份南海夏季风的情况 总被引：1，自引：0，他引：1
将流的标准化变差度概念应用到各年南海夏季风建立研究中去,并用其作为大气环流调整的客观定量指标。用该指标定义的南海夏季风建立的预兆日期与用传统天气气候学方法确定的南海夏季风的来临日期,在绝大多数具体年份两者均很接近,故可作南海夏季风建立的先兆指标。但有一些年份,南海季风的建立不伴随着低空环流的突变过程,两种方法都可能不准确,可靠的方法也许是用场相似度作指标。此外,南海夏季风建立前,对流层顶和平流层下层就出现了环流调整,该调整为南海夏季风建立打下基础,而南海夏季风爆发则表现为低空环流的大调整。南海夏季风的爆发是高、低空全球大气环流发生显著调整的结果,并非限于南海范围局部,南海夏季风建立不能看作是发生在南海的局部现象。 相似文献
7.
资料分析及其同南亚（印度）夏季风的比较,指出建立的突发性和经向分量的重要性是南海夏季风活动的两个最基本特征。根据南海夏季风经向分量与纬向分量同样重要的特征,并考虑南海地区大气环流的基本形势,提出了用对流层高低层散度差构成季风指数,它可以更好地描写南海夏季风的活动。资料分析和大气环流模式（GCM）数值模拟试验都清楚地表明南海夏季风年际异常对大气环流和气候有极为重要的影响,不仅影响东亚地区,而且通过东亚-太平洋-美洲（PJ或称EPA）波列影响美国的天气气候变化。 相似文献
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南海夏季风演变的气候学特征 总被引：17，自引：2，他引：17
本文总结南海北部地区夏季风演变的气候学特征，发现南海地区５月第３候对流层高层东风和北风爆发，对流层低层西风第１次跃升，东亚经向季风环流圈开始形成，这可以成为南海地区夏季风爆发的标志。对流层低层西风在６月中旬开始的第２次连续跃升对应江淮地区的梅雨爆发期。类似地，中国大陆夏季对流层低层５月初和６月初有两次爆发性增暖过程，第２次比第１次强烈得多。南海北部地区对流层低层纬向风速、比湿盛夏呈双峰型，纬向风速峰值分别出现在６月第５候和８月第４候，比湿峰值分别出现在６月第６候和８月第５候。比湿突升对应纬向风速突升，但略落后于风速峰值出现的时间。南海北部地区季风爆发前，温度是波动式上升的，南海季风爆发后，温度是波动式下降的。中国大陆东部及南海地区夏季对流层低层比湿分布有３次突变，即４月中旬南海北部比湿突增，并开始出现高比湿中心，而南海南部为最大比湿中心；５月中旬最大比湿中心已从南海南部跳到了南海北部－华南并向江淮流域扩展；６月中旬江淮流域比湿突增并一直维持到８月，同时南海南部高比湿带消失。而５月中旬ＯＬＲ有一次突变，ＯＬＲ低值区爆发性向北扩张，这对应于南海地区夏季风的爆发。而孟加拉湾地区夏季风演变的气候学特征与南海地区有较 相似文献
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《气象与环境学报》2018,(5)
基于1968—1997年美国国家大气研究中心/美国国家环境预报中心(National Center for Atmospheric Research/National Centers for Environmental Prediction,NCAR/NCEP)共30 a平均的全球各标准等压面上经纬网格距为2.5°×2.5°的逐日气候风场资料,对南海夏季风和南亚夏季风建立期间气候逐日风场的相似度进行了分析。结果表明:风场相似度能较好地反映亚洲热带夏季风的建立,在南海夏季风和南亚夏季风建立期间的季风区,对流层低层风场相似度等值线的水平梯度较大,可视为"相似度锋区",季风沿其法线方向推进。在南海夏季风和南亚夏季风建立过程中,对流层低层大气环流的变化较中层剧烈。在对流层低层,气候状态的南海夏季风最早在西太平洋暖池洋面建立,数日后则已覆盖整个南海,南海和南亚夏季风建立是低层大气环流的突变过程;相应南亚夏季风则最早在赤道东印度洋和赤道西印度洋建立,进而覆盖整个南亚次大陆,其突变性不及南海夏季风。亚洲热带夏季风建立时除季风区及附近外,在全球个别地区大气环流的调整也相当剧烈,甚至发生突变。 相似文献
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2013年5月华南强降水与中国南海夏季风爆发 总被引：2，自引：0，他引：2
利用2013年"华南季风强降水外场试验与研究"的外场试验数据、美国NCEP FNL资料和卫星云顶黑体辐射温度资料,对2013年5月7—17日华南地区出现的两次强降水过程(7—12日和14—17日)中的高低空环流以及相关气象要素场的变化进行了对比分析。中国南海夏季风于5月第3候建立,两次过程分处于夏季风爆发前后。通过对比影响两次强降水过程的主要环流系统如南亚高压、高空副热带西风急流、500 hPa环流型、水汽来源等,指出影响两次强降水过程大尺度环流场之间的显著区别,说明南海季风爆发前后大尺度环流场对暴雨影响的典型差异。7—12日过程主要受北方锋面影响和南方暖湿气流辐合作用,导致华南地区出现南北两条雨带。14—17日过程则由于季风爆发后强的暖湿空气活动致使华南地区对流活跃,从而形成一条位于广东北部的雨带,此次过程强降水比第1次过程集中且对流性更强。两次降水过程的内在物理机制是一个准平衡态的热力适应过程,由于第2次过程降水更强,导致热源作用明显增强,动力向热力的适应过程也更显著。利用探空资料揭示出两次过程暖区暴雨大气热力和动力条件存在显著区别,7—12日南海季风爆发前的暖区暴雨主要受低层强垂直风切变导致的大气斜压不稳定影响;14—17日南海季风爆发后的暖区暴雨主要受高低空急流的强耦合作用影响。 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.
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
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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
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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
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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
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《大气和海洋科学快报》2013,(4):227
正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. 相似文献
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《大气和海洋科学快报》2014,7(6):F0003-F0003
AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
18.
《大气和海洋科学快报》2014,(5):F0003-F0003
AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome. 相似文献
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《大气科学进展》2014,(6)
正Aims Scope Advances in Atmospheric Sciences(AAS)is an international journal on the dynamics,physics,and chemistry of the atmosphere and ocean with papers across the full range of the atmospheric sciences,co-published bimonthly by Science Press and Springer.The journal includes Articles,Note and Correspondence,and Letters.Contributions from all over the world are welcome. 相似文献