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1.
台风Matmo(1410)和Polly(9216)影响辽东半岛时的路径近乎重合,但台风Polly造成了大范围的暴雨和大暴雨,而台风Matmo仅个别测站出现暴雨。利用中国气象局热带气旋年鉴、FY-2D卫星的黑体亮度温度(TBB)产品(0.1°×0.1°)、日本气象厅TBB资料、大连地区逐时自动气象站降雨量资料、常规观测资料和欧洲中期数值预报中心ERA-Interim全球再分析资料(0.125°×0.125°),对两个台风影响辽东半岛的降水过程进行了对比分析。结果表明:(1)两个台风均进入西风槽区而变性,在其西侧和北侧分别具有冷锋和暖锋锋生,辽东半岛的降水均发生在台风低压环流北侧的锋生区和环境风垂直切变明显增大过程中。但两个变性台风的大尺度环流背景却差异显著,台风Polly与西北侧较强冷空气相互作用,锋区随高度增加向西北倾斜,且与低空东南急流相连获得丰富水汽供应,强降水持续时间长,而台风Matmo与东北部对流层低层冷空气相互作用明显,锋区随高度增加略向东北倾斜,但其低空急流水汽通道被快速隔断,不稳定度和动力抬升条件减弱,强降水持续时间短。(2)台风Polly和Matmo的降水分布非对称明显,均出现在顺垂直切变方向的左侧,但台风相对于高空槽的位置不同,对流活动发展的方位有所差异。台风Polly中尺度对流活动在其北侧发展旺盛,且向西南弯曲,而台风Matmo对流活动仅发生在台风环流东北侧。(3)台风的强降水落区还与其低层环流内冷、暖平流的活动密切相关。台风Polly西北侧的冷平流加强,辽东半岛位于台风北侧低层冷暖平流交汇区,水平辐合加强,深厚的上升运动维持,而台风Matmo东北侧的冷平流加强,辽东半岛逐渐位于台风西侧,低层为冷平流控制的下沉运动区,大气层结趋于稳定。 相似文献
2.
利用中国气象局热带气旋年鉴、FY-2D（0.1°×0.1°）云顶亮温、逐时自动气象站降雨量、常规观测资料和NCEP/NCAR再分析资料,运用锋生函数对台风“麦德姆”（Matmo,1410）影响辽东半岛和山东半岛期间的降水特征进行了诊断分析。结果表明：1）Matmo影响辽东半岛和山东半岛期间,其低压环流与西风带高空槽相互作用,在其西侧和东北侧分别有冷锋和暖锋锋生,两条锋带均向东移。强锋生区首先在低层生成,随后尽管高空锋区向下延伸,但并未与低层冷锋重合,低层冷锋锋生强度减弱。2）山东半岛和辽东半岛的降水均发生在台风低压环流的锋生过程中,但山东半岛的降水明显多于辽东半岛。这与锋生强度密切相关,辽东半岛的锋生强度和垂直运动较山东半岛明显偏弱。3）强降水与台风环流内冷、暖平流活动密切相关,冷暖平流交汇之处对强降水有较好的示踪作用。山东半岛始终处于冷暖平流交汇处,其西侧斜压不稳定加强,上升运动发展,强降水出现在冷锋带上暖平流区内;而辽东半岛由冷平流转为暖平流时,对流运动向其东北方向发展,强降水位于辽东半岛东北部。 相似文献
3.
利用气旋相空间法(cyclone phase space,CPS)对1403号台风Faxai变性前后的环境场及结构演变特征进行分析。结果表明:相空间法能够很好地指示低纬变性台风Faxai的变性起止时间。此次过程是由减弱的台风环流与TC西北侧的短波槽结合发展产生,分析台风Faxai的结构演变特征可知,变性阶段TC低层厚度场由均匀对称分布转为非均匀分布,增大了环境斜压性,变性后B值最大达30 m,为弱的斜压非对称结构。Faxai东侧的偏南风暖湿气流与偏北风气流相交汇,使得经向位温梯度增加从而在TC东北象限形成一带状锋区,锋区正好位于南北两大风圈之间的位置。整个变性阶段Faxai西侧几乎无明显冷锋锋生,只在环流东北侧有一定程度的暖锋锋生,这与典型的锋面气旋的发展过程有所不同。变性前,TC呈现对称分布的暖核结构;变性阶段,冷空气从热带低压西侧对流层中低层下沉入侵,TC呈现左侧冷、右侧暖的非对称斜压结构,中层增温可能与槽后强的下沉气流有关。对锋生函数各分量分析发现,散度场主导了气旋周围的标量锋生,倾斜项的贡献次之,涡度场是引起旋转锋生的主要因素,其余两项可忽略不计。 相似文献
4.
高空槽对9711号台风变性加强影响的数值研究 总被引：26，自引：9，他引：26
9711号台风Winnie是一个在中国大陆长久维持(2—3 d)并产生强降水的热带气旋(TC),在其深入内陆过程中变性加强为一个温带气旋。用MM5V3对不同强度高空槽影响下Winnie的变性加强过程进行了数值研究。结果表明:(1)Winnie变性加强过程表现为强锋面侵入台风内部、冷空气包裹台风中心、一个温带气旋在近地层锋面上强烈发展的过程;(2)Winnie在陆上的变性加强与西风带高空槽的强度密切相关。TC与不同强度高空槽相互作用过程中,较深槽携带较强冷平流、正涡度平流以及较强的槽前高空辐散,从而有利于TC的维持和变性发展。数值试验中,高空槽越强,Winnie变性加强越明显,温带气旋的发展越快;(3)模拟结果的位涡分析表明,Winnie的温带变性发展与对流层高层正位涡下传、低层锋区和TC低压环流三者之间的相互作用有关。 相似文献
5.
《高原气象》2018,(5)
利用地面气象观测资料、ERA-Interim再分析数据以及DEM地形数据,使用合成分析方法,从大气环流场、锋面附近要素场及锋生函数诊断场探讨了昆明准静止锋在西进、东退及维持时的结构特征。结果表明,当锋后低层到地面等温线呈"V"型分布,锋后正的次级环流相对深厚,锋面易西进;当锋后低层呈较深厚的逆温层且锋后正次级环流较浅薄,锋面易东退;当逆温层仅限于低层而近地面为冷中心,锋面易维持。东西风风速零线西端在锋面左侧,锋面易西进,反之锋面易东退;零线的位置与锋面基本重合,锋面易维持。垂直运动倾斜项在锋面西进时105°E附近迎风坡出现强烈的锋消现象,锋面东退和维持时出现弱锋生现象。水平辐散项产生的强锋生区在锋面左侧时,指示锋面西进;强锋生区在锋面右侧,且锋生现象很弱时,指示锋面东退;锋面维持时,强锋生区与锋区基本重合。水平变形项中切变变形起主要的锋生作用,而由于冷气团受迎风坡影响,导致伸缩变形在104°E以东的锋后区域产生较强的锋生现象。 相似文献
6.
使用常规观测资料、卫星云图、雷达回波资料、自动气象站降水量以及0.25°×0.25°的NCEP/NCAR再分析资料,对2017年8月1日发生在黑龙江南部的暖区暴雨过程的中尺度特征及成因进行了分析。结果表明:暴雨发生在副高加强西伸北抬及有台风活动的背景下,副高外围的水汽输送为暴雨提供了充沛的水汽条件;低层西南风的增大导致暖锋锋生,暖锋的辐合抬升作用加强,造成较大范围的暴雨天气;锋生区附近存在CSI,锋生作用及CSI的释放,加强了沿着锋面倾斜向上的斜升气流及锋面次级环流,CSI导致的斜升气流的发展进一步触发对流不稳定,导致大范围的垂直上升运动,降水显著加强;暖锋云带内部探空分析显示大气处于不稳定状态,有利于以短时强降水为主的对流发展。暴雨是由云团的后向传播造成的,强降水以暖云降水为主,降水效率高,雨强大,暖锋稳定少动,由暖锋锋生所致的对流单体在同一区域重复新生,并沿暖锋自西向东传播,形成列车效应,暴雨中心一直有最大反射率因子超过45 d Bz且降水效率高的强回波活动,持续时间超过4 h,导致强降水持续时间长,降水累积量大。 相似文献
7.
Winnie(9711)台风变性加强过程中的降水变化研究 总被引：9，自引：1，他引：8
热带气旋变性过程是其结构、强度及其风雨分布发生显著变化的过程,常导致预报失败。基于T106格点分析资料、日本气象厅TBB资料以及MM5V3数值模式结果,对9711号台风Winnie变性加强过程中的降水变化特征及其机理进行研究。结果表明,Winnie台风变性加强过程中降水分布非对称性明显,强降水带首先出现在台风环流北部,之后向南弯曲,其强降水中心绕台风中心从北部顺时针转向东北和东南部。这种降水变化一方面与Winnie与西风带高空槽相互作用过程中环境风垂直切变明显增大,且其指向顺时针旋转有关。此间台风垂直结构发生明显倾斜,变性前期涡旋环流随高度增加先向北倾斜,发展到最强时又趋于垂直,之后又向东南倾斜。强降水区出现在垂直切变的下风方、台风气柱倾斜方向一侧。另一方面还与台风环流内冷、暖平流活动紧密相关,强降水落区与低层暖平流输送位置关系密切。对流涡度矢量垂直分量反映了Winnie台风环流内中尺度锋区与风垂直切变的相互作用,800 hPa上的大值区对其强降水落区有较好的指示意义。 相似文献
8.
《气象与环境学报》2018,(6)
利用常规和加密气象观测资料、美国环境预报中心(National Center of Environmental Prediction,NCEP)的再分析格点资料及FY-2E卫星云顶亮温(Temperature of Black Body,TBB)观测资料,对2010年和2016年5月初黑龙江省两次罕见的春季暖锋暴雨过程进行追踪和诊断分析,探究两次春季暴雨过程的动力、水汽和不稳定条件及暴雨期间暖锋锋生和对称不稳定特征。结果表明:黑龙江省5月初两次暴雨过程的高空影响系统均为高空槽切断成冷涡,只是新生冷涡位置不同,导致暴雨落区不同。两次暴雨过程均出现了垂直于暖锋的次级环流,次级环流的出现有利于加强上升运动,从而加强降雨强度。两次暴雨过程大气均表现为热力稳定结构,暖锋前冷区低层有冷垫,并伴有弱下沉运动,暖湿空气在冷垫之上沿着锋面爬升,是造成持续性降雨的主要原因;不同之处在于2016年暴雨过程锋面之下的冷空气中,下沉运动的范围和厚度更大,冷垫和地形的共同作用使上升运动主要出现在锋区中上层。两次暴雨过程均发生在暖锋锋生时,降雨与锋生相伴,锋生最强时段也是降雨强度最大的时段;锋生作用减弱,降雨强度亦减弱;转为锋消时,降雨结束。对流层中层的湿对称不稳定,有利于降雨的维持和发展,并出现了与暖锋相平行的中尺度雨带特征。 相似文献
9.
1991年梅雨锋暴雨与锋生环流的诊断分析 总被引：3，自引：5，他引：3
利用原始方程模式锋生环流诊断方程对１９９１年７月一次梅雨锋暴雨过程进行诊断分析。计算结果表明，锋面横向次级环流在低层是一个热力正环流，低空急流出口区的次级环流使锋面附近的上升运动得到加强：１００ｈＰａ青藏高压东侧的偏北风与中层的偏南风耦合形成择流层上层的反环流叠加在锋面横向环流上形成深厚的上升气流区是暴雨发生的动力条件。 相似文献
10.
9711号台风Winnie和0010号台风Bills均在中国大陆发生变性，但前者变性后再度加强，而后者变性后减弱消亡。从湿位涡理论出发，对比分析两者的变性过程，结果表明：作为变性台风，Winnie和Bilis均在北上过程中与中纬度西风槽发生作用，但前者与高空槽发生耦合，后者仅接近高空槽底部，没有发生耦合；Winnie变性加强过程表现为一个温带气旋在低层锋区上的强烈发展过程，主要与高层正位涡扰动下传、低层锋区及热带气旋低压环流之间的相互作用有关。Pm湿斜压项增长引起的倾斜涡度发展是登陆热带气旋变性加强的主要因子。在Bills变性过程中，高层无明显的正位涡扰动下传，热带气旋低压环流内无锋区面出现，大气斜压性弱且变化不明显。 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.
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
13.
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
14.
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
15.
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
16.
《大气和海洋科学快报》2013,(1):67
正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.SUBMISSIONAll submitted 相似文献
17.
18.
<正>With the support of specialized funds for national science institutions,the Guangzhou Institute of Tropical and Marine Meteorology,China Meteorological Administration set up in October 2008 an experiment base for marine meteorology and a number of observation systems for the coastal boundary layer,air-sea flux,marine environmental elements,and basic meteorological elements at Bohe town,Maoming city,Guangdong province,in the northern part of the South China Sea. 相似文献
19.
《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
20.
《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