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利用2003、2005年夏季欧亚范围内高空探测资料,采用天气学、动力诊断等方法对夏半年发生在青藏高原东北侧干旱半干旱地区的持续强降水分析认为：欧亚中高纬度与中低纬度500hPa槽脊的反位相分布是该地区产生持续强降水的一种有利机制,其中乌拉尔山阻塞高压与西太平洋副热带高压的配置及稳定少动为这一地区强降水的维持奠定了大尺度的环流背景条件。贝加尔湖低压底部分裂小槽引导冷空气与副高西北侧暖湿气流在高原东北侧一带反复交绥是强降水的主要成因。这种持续强降水的发生为降水相对稀少的高原东北侧地区提供了十分有利的水资源条件,也易诱发洪涝灾害。 相似文献
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2012年7月华北降水异常成因分析 总被引：1，自引：1，他引：0
2012年7月,我国华北地区降水较常年偏多近45%,期间出现了严重的洪涝灾害。本文利用中国台站降水等资料,对华北降水异常现象及其可能成因进行了分析。结果表明,多因子共同作用可能造成了7月华北降水异常偏多。2012年7月,欧亚中高纬地区维持两脊一槽环流型,贝加尔湖附近低槽活动造成冷空气频繁南下。同时,西太平洋副热带高压(以下简称副高)明显偏北带来的充沛水汽与北方冷空气持续交汇于华北地区,共同构成了华北地区降水偏多的大尺度环流形势。分析还发现,西太平洋暖池区海温偏暖,产生的强盛对流活动使西太平洋副高位置偏北。同时,受北太平洋地区海温偏暖影响,东亚东北部—北太平洋地区盛行低层反气旋异常环流,也造成副高位置偏北。 相似文献
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利用福建省66个气象站逐日降水资料、NCEP/NCAR再分析资料和NOAA逐日OLR资料,分析福建省2018年3—6月干旱事件的大尺度环流及其变化特征。结果表明:福建省2018年3—6月降水均偏少,暴雨日偏少,持续性暴雨过程弱,导致严重气象干旱。受拉尼娜的滞后影响,福建处在下沉气流中心,阻塞高压偏弱,西太平洋副热带高压较常年偏弱、偏南、偏东,福建处于水汽通量辐散异常中心区,这是造成福建该时段干旱的环流背景。环流变化显示,前期的阻塞高压、副热带高压和热带对流北传均不活跃,导致暴雨日偏少,干旱发展;后期环流呈现阶段性振荡特征,南北系统的有效配合为持续性暴雨发生提供了有利的环流条件,干旱得以缓解。 相似文献
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《干旱气象》2015,(6)
基于1981~2012年宜昌站日均流量、长江上游287个气象站逐日雨量及NCEP再分析资料,选取长江上游中小洪水过程128例,分析其洪水、致洪降雨月分布特征,并研究其天气成因。结果表明:长江上游流域中小洪水多发于7~9月,且过程持续时间6~9月呈逐渐变长趋势,其中过程洪量7月最大,洪峰流量及次洪量最大值出现在8月。6月副热带高压(以下简称副高)及南亚高压偏东偏南,贝加尔湖槽引导冷空气南下,与西南急流在重庆—宜昌、乌江汇合,造成降水各子流域分布不均,中心位置偏东,强降水日数少但强度较大;7月副高及南亚高压西伸北抬,中高纬地区多短波槽活动,西南气流强盛,辐合区范围大,造成降水范围广且分布均匀,强降水日数多;8月副高进一步西伸北抬,中高纬环流平直,辐合中心位于长江上游流域西北部,配合高热高湿的环境场,造成降水分布不均匀且局地性强,中心位于岷沱江,过程面雨量大;9月以后,副高继续西伸,南亚高压南压东移,受深厚东北槽影响,地面冷空气活跃,西南暖湿气流减弱,降水中心位于岷沱江、嘉陵江,强度减弱,过程面雨量小。 相似文献
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对1991年5-7月江淮流域持续性暴雨的环流异常进行分析,比较造成此次洪涝的水汽输送和冷空气活动重要性。结果表明：（1）东亚大槽维持在中国东北上空发展明显,同时鄂霍次克海上空没有建立强大阻高,这种形势有利于冷空气持续向南侵袭,盛行经向环流。此外,低纬度地区,西太平洋副热带高压主体位置于常年同期相比,明显偏西、偏强,有利于暖湿气流沿副热带高压北上到达江淮流域,与北方冷空气辐合形成强降水。（2）通过定义IT和Iq分别表征温度与水汽对降水的贡献,发现此次江淮流域地区强降水是由对流层低层水汽异常增多和气温异常偏低共同造成的,作用基本相当。 相似文献
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南疆作为气候干旱区,夏季常发生不同类型的降水,2013年6月南疆短历时、高强度、小范围降水事件和2016年8月长时间、持续型、大范围降水事件在预报和服务方面有较大差异。分析两次强降水事件,南亚高压双体型是南疆夏季强降水的大尺度环流背景。高强度降水事件环流经向度大,高、中、低纬低槽同位相叠加,是造成强降水的直接影响系统;持续型强降水事件在500 hPa高空平均环流场上显示,欧亚范围内中高纬度地区为两脊一槽的经向环流,西西伯利亚至中亚地区的副热带大槽呈东北—西南向分布,长波槽底伸至38°N附近,是造成持续型强降水和气温持续下降或偏低的直接影响系统。本文在预报基础上,从气象服务的角度出发,结合长期、中短期、短时临近天气预报,重点分析在时间、范围和强度等方面存在明显差异的不同类型强降水过程中气象服务的递进式思路和方法,为精细化气象服务提供参考。 相似文献
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热带环流异常对1998年长江流域特大洪涝的影响 总被引：1，自引：0，他引：1
分析了造成1998年长江流域特大洪涝灾害的大尺度热带环流成因.指出1998年处在热带环流强度偏弱的气候阶段,西太平洋暖池地区对流活动偏弱,南海热带夏季风持续异常偏弱,副热带夏季风偏强是造成长江持续强降水的主要原因;西太平洋热带对流层高低层环流系统的异常分布,为1998年长江特大洪涝提供了有利的环流背景.还探讨了热带环流异常影响我国夏季降水的可能途径,它们的关系在1998年夏季降水预测中得到应用. 相似文献
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利用MICAPS系统资料对2005年8月12日发生在山西朔州市北部的暴雨天气过程的大尺度环流背景和物理量场进行分析。结果表明:这次暴雨天气过程发生在纬向环流向经向环流调整的过程中,西太平洋副热带高压有一次明显的西伸北抬,是一次典型的副高西北侧西南气流型暴雨。降水水汽主要来自南海,中低层的水汽输送十分充沛,并在朔州市北部形成辐合。低空急流的建立,为此次强降水提供了丰富的水汽和位势不稳定能量;过程期间,物理量场表现出强水汽输送辐合及上升运动;冷空气与暖湿气流及特殊地形的综合作用激发出中尺度降水云团,造成此次强降水。 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
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《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