吉泰盆地夏季一次暴雨天气过程中尺度对流系统演变特征          下载免费PDF全文

李婕  占龙飞  徐星生  金米娜  孙素琴 《气象与减灾研究》2022,45(4):241-252

利用地面气象观测、FY-2G卫星TBB、多普勒雷达、ERA5再分析资料,以及江西快速循环同化系统等资料,分析了2020年7月9日吉泰盆地梅雨期特大暴雨天气过程的中尺度系统演变特征及机制。过程分为线状对流系统MCS-A转向、南压阶段和单体对流系统MCS-B、MCS-C北移发展阶段。结合盆地西侧山区、盆地北部、盆地南部三个暴雨区,重点分析了暴雨天气过程的第一阶段。结果表明：1)边界层辐合线触发MCS-A,后者西侧不断并入边界层辐合线上和低空急流前端的新生单体,形成“列车效应”。2)弱降水冷池驱动MCS-A中强降水雨团向西南方向传播以及MCS-A与弱降水雨团合并,共同导致了MCS-A转向。3)受幕府山和吉泰盆地地形绕流作用,对流层中低层中-β尺度低涡在吉泰盆地东北部停留约5 h,激发盆地西部、北部对流活动的发展。4)对流系统处于准静止态,急流前端存在中-γ尺度涡旋,导致MCS-A中强对流单体在吉泰盆地南部长时间维持。  相似文献   

福建省前汛期暴雨天气雷电特征的个例分析   总被引：7，自引：2，他引：5  

林炳干  谢兴生  陶善昌 《南京气象学院学报》1999,22(2):155-163

利用福建省中尺度灾害性天气预警系统（简称福建二级基地）的闪电定位站网、雷达和常规天气观测资料,对１９９７年５月５日至７日晨发生在闽东南沿海各县市一场特大暴雨天气过程的闪电特征及其与降雨的相互关系进行分析。结果表明：这次暴雨过程地闪和云闪总数超过５０００次,闪电密度极值超过１次／ｋｍ＾２,地闪次数超过云闪次数,负地闪占绝对优势,正云闪占２／３以上。暴雨区的闪电频数－时间曲线很好地反映了暴雨过程降水高  相似文献   

A NUMERICAL STUDY OF THE VARIATIONS AND DISTRIBUTIONS OF TROPOSPHERIC OZONE AND ITS PRECURSORS OVER CHINA     

王喜红  李兴生 《Acta Meteorologica Sinica》1999,(1)

By means of a three-dimensional meteorological model(MM5)and a chemical model,thedistributions of tropospheric ozone and its precursors over China have been simulated in summerand winter time,16—18 August 1994 and 7—9 January 1995.The distribution of ozone over theTibetan Plateau in summer time is deeply discussed.The simulated results indicate that thedistributions of surface ozone and NO_x are in good agreement with observed results,and humanactivities and photochemical reactions are the main factors controlling the surface ozone and NO_xconcentrations.In addition,higher ozone concentrations are coincided with the air convergence,and the lower concentrations are related to the air divergence.In summer,over the TibetanPlateau the strong flow convergence results in higher ozone concentrations in the lowertroposphere:and the strong flow divergence results in lower ozone concentrations in the uppertroposphere.In winter time ozone concentrations show Iarge-scale characteristics controlled bywesterly flow,and in the jet area they are lower than those outside the jet.  相似文献   

近地面O3变化化学反应机理的数值研究   总被引：34，自引：1，他引：33  

杨昕  李兴生 《大气科学》1999,23(4):427-438

利用中尺度气象模式（MM5）及区域化学模式（RADM）对中国地区近地面O3变化化学反应机理进行了数值模拟研究。主要研究了近地面O3变化与其主要前体物NMHC（非甲烷烃）、NOx、CO等之间复杂相互作用关系。主要结论为:（1） 污染地区近地面O3变化主要受光化学作用控制;而清洁地区地面O3变化主要受大气背景O3浓度影响。（2）NMHC和NOx的变化对HO2和OH自由基的影响是十分复杂的,O3的反馈作用对自由基的影响是不可忽视的。（3）在高NOx污染地区的地面上空可能出现高O3污染。（4）在O3光化学反应机理中同样存在线性相关关系。  相似文献   

部分待估参数具有先验随机性的WTLS平差     

邓兴升  黄小鹏  彭思淳 《大地测量与地球动力学》2018,38(9):968-973

部分待估参数具有先验随机信息,且误差方程系数矩阵含有观测误差,是一类新的平差问题。本文构造了部分待估参数含有先验随机信息的加权整体最小二乘平差函数模型,推导该模型参数估计与精度评定公式,给出计算步骤,适用于一般情形。实例对比分析证明,该算法正确可靠,迭代收敛速度较优。  相似文献   

Stress relaxation behavior of silty mudstone considering the effect of confining pressure     

Huaichang Yu  Xingsheng Zhang  Handong Liu  Zhiquan Huang  Guangcheng Shi 《Environmental Earth Sciences》2016,75(12):1001

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快速更新循环同化在江西暴雨数值模拟中的应用     

徐星生  肖安  万明  张娟娟 《气象与减灾研究》2011,34(3):24-29

基于WRF 模式三维同化(3DVar)建立每3 h 快速更新循环同化系统(简称RUC),循环同化地面常规观测资料、探空资料、船舶资料和飞机报,并以此为基础建立预报系统,对2011 年6 月4 日20 时-5 日20 时江西一次大暴雨过程进行模拟检验,初步研究RUC 在江西暴雨预报中的应用.结果表明:(1)RUC 有效改...  相似文献   

INTERCOMPARISON OF OZONE VERTICAL PROFILES BETWEEN ECC OZONESONDE AND BREWER UMKEHR MADE OVER QINGHAI PLATEAU OF CHINA^*     

Liu Qijun  Zheng Xiangdong  Luo Chao  Tang Jie  Ding Guoan  Li Xingsheng  Zhou Xiuji 《Acta Meteorologica Sinica》1998,12(1):103-111

From October 1995 to August 1996.a total of 50 ECC(electrochemical concentration cell) ozonesoundings were made in Xining(36.43°N,101.45°E,2296 m ASL)to study the distribution and seasonal characteristics of ozone profile,and intercompare the Brewer Umkehr ozone profiles obtained at Waliguan Baseline Station over the Qinghai Plateau.It was demonstrated that(1) Umkehr produced estimates of the ozone comparing with ECC profiles were accurate to better than 25% in the 20-38 km altitude range,and where 23-33 km region was the most accurate,within about 15% of the ECC ozonesonde:(2)higher differences between Brewer Umkehr and ECC ozonesonde occurred in the troposphere and lower stratosphere;and ozone amounts were overestimated in Umkehr layers 1,2 and 3,and were underestimated in Umkehr layers 6 and 7 by Brewer Umkehr method.  相似文献   

A New Nodosaurid Ankylosaur from the Chaochuan Formation of Dongyang, Zhejiang Province, China     

CHEN Rongjun  ZHENG Wenjie  Yoichi AZUMA  Masateru SHIBATA  LOU Tianliang  JIN Qiang  JIN Xingsheng 《《地质学报》英文版》2013,87(3):658-671

Dongyangopelta yangyanensis gen. et sp. nov. from the Chaochuan Formation (Albian-Cenomanian) of Dongyang, Zhejiang Province, China is characterized: the convex anterior surface of the first presacral rod centrum strongly inflates laterally and slightly curves posteriorly; the fused pelvic shield composes of larger pebble-shaped bosses, defined by smaller tubercles or flat stretches of bone; most osteoderms are heavily roughened with notches and grooves for dermal attachment along the edge; domed triradiate osteoderm is present; sigmoid curvature of the dorsal surface of the ilium is present; the preacetabular process curves lateroventrally at the anterior end and has a shallow groove in the edge of the lateral and anterior ends and strong lateromedial expansion of the distal femur. The femoral head is well separated from the greater trochanter, indicating that Dongyangopelta is a nodosaurid ankylosaur, the second from southeast China. Phylogenetic analysis also positions this taxon in the Nodosauridae clade. Dongyangopelta differs from Zhejiangosaurus in the characters of presacral rod, ilium, and femur. Dongyangopelta represents the first ankylosaur outside North America and Europe that definitively possesses a pelvic shield with fused armor.  相似文献   

基于RMS参数的水雷使用可用度分配模型研究          下载免费PDF全文

夏中亚  李兴生 《数字海洋与水下攻防》2022,5(1):59-65

为了确定合理有效的使用可用度,综合考虑水雷装备任务需求、保障方案以及相似装备的RMS指标等信息,构建了基于多影响因素的水雷装备使用可用度分配计算模型.以某型水雷为例,综合权衡后分配给子系统使用可用度和相关RMS参数指标,验证了该方法的可行性.该分配模型合理、可信,具有通用性,可根据实际情况修改影响因素的权值系数,满足不...  相似文献