非地转湿Q矢量在台风暴雨预报中的应用试验     

张亚洲  邵邹  邓文彬  赵文斌 《气象与减灾研究》2011,(4):23-29

利用NCEP/NCAR全球格点资料和TRMM卫星资料,采用改进后的非地转湿Q矢量,对0908号台风“莫拉克”引起的台湾南部特大暴雨过程进行预报应用试验.试验结果表明:(1) 850hPa高度层的非地转湿Q矢量散度及水汽通量散度分布可以预报未来24 h暴雨的落区及其雨带的分布,暴雨发生在Q矢量散度梯度大值区靠近辐合区域,...  相似文献   

The effect of wave-induced radiation stress on storm surge during Typhoon Saomai (2006)   总被引：5，自引：1，他引：4  

FENG Xingru  YIN Baoshu  YANG Dezhou  WILLIAM Perrie 《海洋学报(英文版)》2011,30(3):20-26

The effects of wave-induced radiation stress on storm surge were simulated during Typhoon Saomai using a wave-current coupled model based on ROMS (Regional Ocean Modeling System) ocean model and SWAN (Simulating Waves Nearshore) wave model.The results show that radiation stress can cause both set-up and set-down in the storm surge.Wave-induced set-up near the coast can be explained by decreasing significant wave heights as the waves propagate shoreward in an approximately uniform direction;wave-induced set-down far from the coast can be explained by the waves propagating in an approximately uniform direction with increasing significant wave heights.The shoreward radiation stress is the essential reason for the wave-induced set-up along the coast.The occurrence of set-down can be also explained by the divergence of the radiation stress.The maximum wave-induced set-up occurs on the right side of the Typhoon path,whereas the maximum wave induced set-down occurs on the left side.  相似文献   

Evidence of late oligocene/early miocene backthrusting in the central alpine “root zone”     

Peter Heitzmann 《Geodinamica Acta》2013,26(3):183-192

Abstract

Two groups of stretching lineations can be distinguished in the Central Alpine " root zone " between Ticino and Mera :

1) Steeply plunging lineations formed during retrograde metamor-Phism under amphibolite/greenschist facies conditions indicate an uplift movement of the Central Alps. The lineations can be related to an important back-thrusting event of late Oligocene/early Miocene age.

2) Gently plunging lineations formed under lower greenschist facies conditions display a pattern typical of a dextral strike-slip system. These lineations are of early Miocene age.

This cpmbined movement, achieved by ductile deformation along the lnsubric line was followed by a stage of brittle deformation in a dextral strike-slip system (= Tonale line).

The signification of this interpretation is shown in a new crustal cross section through the Central Alpine/Southern Alpine border zone in the Iicino area.  相似文献   

Further evidence for a relatively high sea level during the penultimate interglacial: open-system U-series ages from La Marina (Alicante,East Spain)     

《Geodinamica Acta》2013,26(6):409-426

The elevation and timing of high sea stands during Oxygen Isotope Stage (OIS) 7 are not as well constrained as those of OIS 5e. Conflicting values are reported from Mediterranean coastlines, and fossil dating is inaccurate because of ubiquitous open U-series systems. New morphostratigraphic data from La Marina (eastern Spain) supported by open-system U-series coral ages shed light on the maximum sea level during OIS 7. Fossil corals (Cladocora caespitosa) underlying an OIS 5e marine unit yielded U-series ages from 178 ± 10 to 208 ± 11 ka (±2s; n=7) with an outlier at 240 ± 18 ka. Mean open-system limit ages of 170 ± 10 (minimum age after correction for 234Th -230Th uptake) and 237 ± 20 ka (maximum age after correction for 238U - 234U uptake) were calculated to have a probable age closer to the minimum value, for an assignment of OIS 7a or 7c. The occurrence of a warm-water “Senegalese” fauna (Strombus bubonius) in OIS5e and OIS 7 marine units confirms the arrival of tropical species to the Mediterranean before the last interglacial period. Morpho-sedimentological and neotectonic studies suggest that the maximum paleo-sea level during OIS 7c or 7a was a few meters below that of OIS 5e.  相似文献   

极地冰层回转钻进切削热量测试装置的研制     

刘春朋  曹品鲁  白杨  Pavel Talalay  郑治川 《探矿工程》2013,40(12):13-17

极地冰盖深部“暖冰”层钻进时,由于冰层的温度较高,接近甚至达到冰的压力熔点,回转钻进时产生的切削热量极易使冰屑融化,导致机械钻速慢、取心率低、卡钻事故频发。钻压、转速、切削具结构等参数均对切削热量有一定的影响,有必要设计一套实验装置对切削热量进行测试,从而为设计切削具结构、优化钻进参数组合提供理论依据。以XY-1型岩心钻机钻进系统为平台,利用无线信号传输原理设计了冰层回转钻进切削热量测试实验台。初步测试结果表明,该实验装置能够准确测量钻压、扭矩、切削温度等参数,可用来进行相关的实验研究。  相似文献   

“碧利斯”(0604)暴雨过程不同类型降水云微物理特征分析   总被引：2，自引：3，他引：2  

汪亚萍  崔晓鹏  任晨平  余晖 《大气科学》2015,39(3):548-558

本文利用"碧利斯"(0604)暴雨增幅过程高分辨率的数值模拟资料, 将降水分成对流降水和层云降水, 对比分析了不同类型降水云微物理特征和过程的差异, 探讨了不同类型降水对暴雨增幅的贡献, 结果指出:(1)暴雨增幅前, 降水基本为层云降水, 对流降水只存在于零星的几个小区域, 暴雨增幅发生时段, 对流降水所占比例较暴雨增幅前有显著增加, 平均降水强度达层云降水强度的3倍多。(2)暴雨增幅时段, 云系发展更加旺盛, 云中各种水凝物含量较增幅前明显增加, 其中, 对流和层云降水区云中水凝物含量均有一定程度增长, 但对流降水区增加更显著;而无论增幅前还是增幅时段, 对流降水区云中水凝物含量均要明显大于层云降水区, 并且两者的这种差异随着地面降水强度的增强而增大。(3)暴雨增幅前后, 对流降水区雨滴的两个主要来源最终均可以追踪到云水, 通过云水与大的液相粒子(雨滴)和大的固相粒子(雪)之间、以及大的固相粒子(雪和霰)之间的相互作用和转化, 造成雨滴增长, 并最终形成地面降水, 而层云降水区中与雨滴形成相关的上述主要云微物理过程明显变弱, 但层云降水区中暴雨增幅时段的上述过程又要强于增幅前, 说明层云降水对暴雨增幅也有一定贡献。  相似文献   

“尤特”特大暴雨过程的热力条件分析   总被引：1，自引：1，他引：1  

程正泉  林良勋  沙天阳  杨国杰 《气象》2014,40(12):1507-1512

1311号强台风尤特登陆后给广东带来持续性大范围强降水,对流降水特征十分显著。文章分析了"尤特"影响期间大尺度环流背景,重点讨论了此次持续性强降水过程中大气层结问题。发现低空急流向广东输送强的暖平流,是广东大气层结不稳定得以持续维持的根本原因。进一步分析发现,低空急流本身并不是"暖"的,当"尤特"趋向陆地时,陆地上的暖气团在"尤特"环流强迫下向南传播扩散,低空急流穿越这一暖区时温度升高才具备"暖"的特性。温度诊断方程结果进一步证实这一点。通过个例反查,在许多登陆后造成连续强降水的台风过程中均发现了这一特征。因此,台风登陆引起环境温度场的演变以及与低空急流的配置需引起业务预报上的重视。  相似文献   

厄尔尼诺和反厄尔尼诺事件与西北太平洋台风活动   总被引：42，自引：12，他引：42  

何敏  宋文玲  陈兴芳 《热带气象学报》1999,15(1):17-25

用统计相关和典型年合成方法分析了厄尔尼诺和反厄尔尼诺事件与西北太平洋台风活动的关系，指出厄尔尼诺年台风活动减少，反厄尔尼诺年台风活动增加，而且台风活动与厄尔尼诺、反厄尔尼诺事件起始和终止时间、强度、台风生成区域有关。利用厄尔尼诺和反厄尔尼诺年台风活动频数的统计特征，及台风频数与海温等要素的时滞相关关系，为台风频数的预测提供了有益的信息。还应用奇异值分解方法，分析了高度场和海温场的相关关系。结果表明，厄尔尼诺年海气耦合作用将造成不利于台风发展的环流条件，因此台风偏少，反厄尔尼诺年则出现相反的情况。  相似文献   

“云娜”台风影响的商城特大暴雨过程分析   总被引：1，自引：0，他引：1  

朱文洁王志强  孙永霞冯庆合  朱艳红易亮 《河南气象》2006,(1):25-26

利用常规资料、天气图、物理量诊断分析等资料,对“云娜”登陆后的特征及其对商城造成特大暴雨的天气过程进行了分析,结果表明:强大深厚的台风低压是主要影响系统;华北地区弱冷空气侵入台风倒槽是主要原因;地形对降水起增幅作用;水汽通量和垂直速度中心与特大暴雨落区一致,对特大暴雨具有指示意义。  相似文献   

成熟台风边界层作用的数值研究   总被引：8，自引：0，他引：8  

张福青  杜华武  蒋全荣 《热带气象学报》1994,10(2):107-114

利用ＴＬ６模式，在对一次台风过程成熟阶段进行成功模拟的基础上，通过各种对比试验，研究了成熟台风边界层的作用。结果表明：在２４小时内，台风边界层内各种通量的垂直输送对其路径影响很小而对成熟台风的维持却有非常重要的作用。其中，潜热输送成为成熟台风的主要能源，其影响最为重要。感热输送对成熟台风几乎无影响。边界层的动量垂直输送具有双重作用，摩擦辐合使上升运动增大，但明显对下层涡旋有削弱作用，这近似于在台风  相似文献