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1.
秦皇岛一次飑线冰雹天气分析 总被引：1，自引：0，他引：1
利用常规探测资料、自动站观测资料、多普勒天气雷达资料等对2014年6月26日发生在秦皇岛市的一次飑线冰雹天气过程大尺度环流背景、雷达回波特征及灾害性冰雹大风形成原因进行了分析。结果表明:本次飑线过程是受高空冷涡后部冷空气、低层暖切变共同作用的结果;飑线过境前后,气象要素变化比较明显,风向突变、风力猛增、气压涌升、气温急降、相对湿度上升;本次强风暴影响系统尺度为中α尺度,"弓"形回波结构明显,同时有雷暴出流边界;速度图上的风速大值区、后侧入流、中低层径向辐合及垂直风廓线图中低层风的转变信息等对大风的预警有明显的预示作用,且从雷达四维变分分析可知850 h Pa辐合上升运动较强,中层有干冷空气入侵;回波垂直剖面图上飑线前沿低层存在有界弱回波区,中高层有回波悬垂。 相似文献
2.
利用常规地面高空观测资料、地面自动站资料、NCEP 1°×1°再分析资料、卫星云图、多普勒天气雷达资料等,对2017年秋季发生在河北省中部的一次由飑线引发的雷暴大风天气进行分析。结果表明：本次雷暴大风过程发生在高空冷涡底部,槽后冷空气与低层暖平流叠加配合地面冷锋的有利天气背景下,由飑线回波直接造成。环境条件中水汽和热力达到了中国华北地区产生强雷暴大风的平均值,大气温度直减率和垂直风切变比夏季更适宜,但能量不如夏季充足。飑线的强度、形态与夏季产生雷暴大风的雷达回波特征无异,但依据低层径向速度大值区预警秋季飑线大风需提高阈值。秋季飑线过程中地面同样伴随风场辐合、雷暴高压等中尺度系统,冷池密度流作用有利于地面大风产生。 相似文献
3.
《贵州气象》2021,(3)
利用常规高空和地面探测、观测资料,地面加密自动站分钟数据资料以及榕江站、贵阳站C波段多普勒天气雷达探测资料,分析了2020年3月23日贵州强对流天气的环流形势,并重点分析了榕江飑线大风及长顺大冰雹雷达回波特征。结果表明:(1)此次飑线大风与大冰雹发生在南支槽前暖区,地面热低压发展推动辐合线移动、低层西南暖湿气流、中层干冷空气、合适的0℃和-20℃高度均为此次飑线大风及大冰雹的产生提供了有利的环境条件。(2)雷达回波大冰雹特征突出:强回波悬垂,有界弱回波区,弓形回波,中心强度强(60 dBz以上)且50 dBz强回波伸展超过-20℃高度达到9 km以上,垂直积分液态水含量最高达到了70 kg/m~2,连续超过两个体扫VIL≥60 kg/m~2,回波顶高连续超过两个体扫在15 km以上。(3)飑线雷达回波大风特征明显:弓形回波形态特征明显且移动较快,移速约40 km/h,低层径向速度大,中层径向辐合大风区下传,速度零线通过观测站后大风加速。(4)短临预警业务中,对飑线大风天气,应重点关注低仰角速度大值区、中层径向辐合和弓形带状回波生成后移动发展对下游地区的影响;对大冰雹天气,应重点关注大于50 dBz强回波垂直扩展的高度、VIL和ET高值区的维持等。 相似文献
4.
利用日常业务常规高空和地面探测、观测资料,地面加密自动站分钟数据资料以及榕江站、贵阳站C波段多普勒天气雷达探测资料,分析了2020年3月23日贵州榕江飑线大风及长顺大冰雹的成因及雷达回波特征 。结果表明：（1）此次飑线大风与大冰雹发生在南支槽前暖区,地面热低压发展推动辐合线移动、低层西南暖湿气流、中层干冷空气、合适的0℃和-20℃高度均为此次飑线大风及大冰雹的产生提供了有利的环境条件。（2）雷达回波大冰雹特征突出：强回波悬垂,有界弱回波区,弓形回波,中心强度强（60dBz以上）且50dBz强回波伸展超过-20℃高度达到9km以上,垂直积分液态水含量最高达到了70kg/m2,连续超过两个体扫VIL≥60kg/m2,回波顶高连续超过两个体扫在15km以上。（3）飑线雷达回波大风特征明显：弓形回波形态特征明显且移动较快,移速约40千米/小时,低层径向速度大,中层径向辐合大风区下传,速度零线通过观测站后大风加速。（4）短临预警业务中,对飑线大风天气,应重点关注低仰角速度大值区、中层径向辐合和弓形带状回波生成后移动发展对下游地区的影响;对大冰雹天气,应重点关注大于50dBZ强回波垂直扩展的高度、VIL和ET高值区的维持等。 相似文献
5.
使用常规观测资料、区域自动站资料、多普勒天气雷达资料、风廓线雷达产品以及GFS (Global Forecast System)0.5°×0.5°再分析资料,分析了2018年3月4日江西极端雷暴大风过程的中尺度特征及其成因,并探讨了该过程的极端性。结果表明:(1)该过程由强飑线横扫江西造成,飑前低压、飑锋、雷暴高压、尾流低压特征清晰。(2)飑线系统进入江西后强烈发展的有利环境条件:低层强暖湿平流、中层干空气、地面增温、低层增湿形成了"上干冷、下暖湿"异常不稳定层结;中层低槽东移、多层急流叠加、地面辐合线共同形成强抬升条件;中低层强的风垂直切变使得飑线生命史延长。(3)飑线与引导气流交角增大,移速异常加快;鄱阳湖地区平坦地形和丰富水汽都可能对地面大风产生增幅作用。(4)南昌站地面低压、下沉对流有效位能(DCAPE)、850 h Pa与500 hPa温度差、925—1 000 h Pa风垂直切变等物理量极端异常,与其多年旬平均差值超过2σ(σ为均方差),对极端雷暴大风潜势预报有一定的指示性。另外,风廓线雷达产品1.0 km以下大风速区提前雷暴大风30 min出现,高层折射率结构常数(C_n~2)大幅跃升提前雷暴大风10～20 min出现,均对其临近预警有一定的参考价值。 相似文献
6.
利用自动站加密观测资料、常规观测资料、NCEP资料以及FY2G、雷达资料,对发生于2016年4月22日的广西暖区飑线过程进行了中尺度分析。结果表明:(1)飑线移动快速(100km·h-1),主要引发湿对流天气(雷暴大风和短时强降雨);飑线过境前气压下降,过境时气温和露点骤降、气压涌升、风向突变、风速陡增,过境后气压再次下降;具有尾流低压、雷暴高压、飑锋和飑前低压等飑中系统特征。(2)此次暖区飑线是在500h Pa高空槽加深东移的大尺度背景下发生的,飑线A初始对流的触发与云贵准静止锋前的地面辐合线密切相关,飑线B初始对流则由红河与玉溪间的露点锋及其锋前西南风和东南风的辐合线所触发,对流触发后随高空槽和中层基本气流向东偏南方向移动发展,影响广西。(3)虽然没有冷锋伴随而下,此次暖区飑线依然是在较强的环境下维持,有较强垂直风切变、较高对流有效位能、层结曲线和露点曲线向上形成"喇叭"状配置(上干下湿对流不稳定);地面辐合线、边界层暖切对飑线的发展和维持有重要作用。 相似文献
7.
利用广东省2 400余个地面自动气象站的观测资料及广州雷达站的多普勒雷达资料对2016年4月13日广东一次强飑线过程的地面中尺度特征和雷达特征进行了分析,结果表明:(1)飑线在发展旺盛时,沿着飑线方向略落后于飑线处有3个强辐合中心,强中心位于飑线凸起处;辐散区落后于飑线,大风区位于辐散中心前侧梯度最大处。大风区造成的气旋式涡度中心略落后于辐合中心。(2)飑线在地面表现为一条中尺度θse锋区。(3)飑线强盛阶段的地面中尺度场上可看到扰动高压处于辐合线顶点后侧偏右区域,扰动高压大小与阵风大小有一定正比关系。扰动低压超前于辐合中心,能作为飑线发展和大风是否出现的判断依据。(4)在飑线的弓形回波阶段的顶点处存在下击暴流,顶点后侧的弱回波通道表明伴有后侧入流急流RIJ,RIJ对弓形回波的形成、地面大风和飑线的维持和快速移动具有重要的作用。 相似文献
8.
利用常规观测资料、多普勒天气雷达资料、地面自动站加密资料、NCEP 1°×1°的再分析资料等对2014年7月18日发生在湘赣地区一次台前飑线过程的环境条件及多普勒天气雷达特征进行研究。结果表明:台前飑线产生前,对流层低层较好的水汽条件、条件不稳定层结以及两者结合形成的高CAPE值均为其发生发展提供了良好的条件;台风倒槽是此次台前飑线过程主要影响系统,露点锋、地面辐合线为其提供了抬升触发和维持加强机制;台前飑线西移北上的过程中出现"弓形"回波、中层径向辐合(MARC)、速度大值区、阵风锋。本次台前飑线和以往研究的西风带飑线存在以下差异:本次飑线低层垂直风切变主要是以风速差为主;中高层的冷空气侵入并不明显;在成熟阶段,气压场上也没有明显的雷暴高压,但有明显正变压;本次飑线过程是发生在暖湿的环境条件下,后侧入流为相对湿度较大的东南急流,雨水蒸发并没有西风带飑线强烈;雷达速度图上虽有MARC特征但最大正负速度差值并不是很大(15~27 m/s)。上述特征可能是该台前飑线过境湖南过程中没有造成极端大风的主要原因之一。 相似文献
9.
利用Himawari-8卫星红外、水汽云图和FY-2E卫星可见光云图资料,以及多普勒天气雷达拼图和常规气象站、自动气象站、高空观测资料,对2017年9月21日发生在山西境内的一次飑线天气过程进行云图特征及维持机制分析。结果表明:(1)蒙古冷涡是本次飑线过程的大尺度天气影响系统,地面冷锋东移至不稳定潜势区触发了飑线云系的生成;高低空系统配置结构的转变及地面中尺度高压外流冷空气与环境风场形成的中尺度气旋和辐合线,是飑线发展和维持的机制;对流云团在地面冷锋与850 hPa切变线之间合并发展,地面中尺度高压与低压的发展促使气压梯度增大,导致飑线增强,是飑线过境时地面大风形成的原因。(2)初生阶段,飑线形成于云顶亮温低值区后侧梯度大值区、云顶纹理粗糙区、干湿边界偏湿区一侧,冷云盖略超前于飑线;发展阶段,飑线回波在云顶亮温低值区加强,并沿着亮温低值中心移动的方向移动;成熟阶段,飑线雷达回波与云顶亮温低值区重合。(3)弧状云线、上冲云顶和对流云带一侧的暗影是对流云团加强发展的前期征兆。 相似文献
10.
2013年湖南首场致灾性强对流天气过程成因分析 总被引：4，自引：0，他引：4
应用湖南多部雷达和探空资料、中小尺度自动气象站资料、南岳高山站逐时观测资料及LAPS局地分析资料,对2013年3月19日湖南首场致灾性强对流天气过程的成因进行综合分析,并探讨强冰雹和雷暴大风预警着眼点及其可预警性。结果表明:强对流发生前,近地面晴空辐射增温、对流不稳定层结、强的垂直风切变、强温度梯度直减率以及近地层较好的水汽条件为强对流风暴发生发展提供了良好的潜势条件;中低层冷平流、地面中尺度辐合线、能量锋和露点锋以及近地面层弱辐散、中低层强辐合、高层强辐散的动力耦合结构是强对流发生的有利天气背景,中低层冷空气是这次强对流过程的触发机制;强对流风暴的前期以超级单体风暴和多单体风暴为主,超级单体风暴东移北上过程中与湖南西部不断新生的对流回波结合后发展成飑线,飑线维持、发展过程中出现"弓形"回波、中层径向辐合(MARC)、低层辐散、速度大值区等特征;在短临预警服务中,中低层明显的钩状回波结构、持续偏高的反射率因子和垂直积分液态水含量(VIL)值为靖州强冰雹预警的发布提供了有效依据,而低仰角距离地面1 km内的径向速度大值区(大于20 m.s-1)则为道县雷暴大风预警提供重要参考。 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