东北冷涡持续活动及与欧亚阻高配置对我国东北地区降水影响研究

发布时间：2018-01-20 23:35

本文关键词： 东北冷涡客观识别时空分布持续活动环流特征强度指数东北降水阻塞高压流型配置能量传播　出处：《兰州大学》2016年博士论文　论文类型：学位论文

【摘要】：东北冷涡是东亚中高纬度地区活跃的高空切断冷涡,一次冷涡过程多为3-5d,可谓天尺度系统。但是,东北冷涡过程频发与否对东北亚地区,乃至我国东部气候异常往往产生重要影响。因此,21世纪初叶,我国学者开始研究并且明确提出东北冷涡“气候效应”这个科学问题,丰富了东北冷涡理论研究的内涵。以往有关北半球中高纬度阻塞形势的理论研究,大都以阻塞高压为主。本文利用1948-2012年NCEP/NCAR全球再分析逐日资料和国家气象信息中心提供的1960-2012年全国气象观测站日降水资料,着重从东北冷涡活动异常为主体出发,首先,研究如何采用机器自动识别的数量化方法,揭示其活动的天气与气候尺度特征,以此为基础进一步丰富其活动的“气候效应”,并开展基于冷涡因子的东北地区月降水预测应用研究。其次,运用同样方法给出亚洲阻塞高压活动的数量化检测结果;研究东北冷涡和阻塞高压活动的配置,尤其是重点探讨中高纬阻塞流型(以乌拉尔山-鄂霍次克海双阻型为主)与东北冷涡二者之间的相互作用及其形成、发展和消亡的过程机理。主要结论如下:(1)给出1948-2012年5-8月东北冷涡活动天气过程,分析其统计学特征,得出冷涡活动以3-6d为主,主要位于121o-131oE,48o-53oN区间;东北冷涡发生频次和活动天数均存在显著增长趋势。5-6月和7-8月东北冷涡活动特多年高度距平合成场与特少年的主要异常区呈反位相分布,且这种反位相特征在对流层中、高层(200 hPa、500 h Pa)均呈近半球尺度的波列分布特征;5-6月和7-8月冷涡活动特少年与特多年差值合成场分布相近,均呈现显著的南北向"+、-"波列分布,正负波列分别位于西北太平洋区域和鄂霍次克海至白令海区域,该波列对应高度层风场中的相对位置为气旋和反气旋式环流。7-8月东北冷涡活动异常多年份,贝湖至鄂海阻高与东北冷涡多同时发生,异常少年份,贝湖至鄂海阻高亦不盛行,以阻高先发生冷涡后发生年份占多数。(2)基于东北冷涡活动时间持续性探讨冷涡持续活动标准,通过强度指数进行定量描述,该指数对冷涡持续活动过程具有较好表征意义。冷涡活动强,5月乌拉尔山至贝加尔湖阻塞形势显著,6月的鄂霍次克海阻塞形势显著,7月中高纬阻塞流型不显著,8月份乌拉尔山-鄂霍次克海双阻活动明显。尤其在6月份,强指数年冷涡系统较深厚,集中于对流层中高层,冷心结构明显,具有一定大气斜压特征;高层存在冷中心,低层配有温度槽,在中高层,西风带呈现明显的上游分流和下游汇合特征,分汇流之间呈现出东北高、西南低的偶极子阻塞形势;6月弱指数年冷涡系统较浅薄,主要集中在对流层中低层,冷心结构不明显,不存在阻塞形势。(3)基于冷涡活动地理分布特征,通过环流持续异常对冷涡的持续性进行了一种新的定义方法—广义“冷涡”,通过定量化描述,给出广义“冷涡”强度指数,得出东北冷涡活动具有显著年际和年代际周期振荡特征,广义“冷涡”强度指数较好刻画冷涡天气过程频发性及其大气环流特征,与东北地区初夏(5-6月)和盛夏(7-8月)冷涡降水分布具有较好对应关系。广义“冷涡”活动强(弱)年,欧亚中高纬环流特征有(不)利于东北冷涡形成、发展和维持,7-8月,东亚区域(不)易形成有利于南方水汽向北输送的环流形势。初夏(不)盛行乌拉尔山阻塞形势,盛夏(不)盛行鄂霍次克海阻塞形势;副热带高压面积偏小(大),向北推进时间偏晚(早),有(不)利于东北冷涡的维持。(4)初夏(5-6月)东北冷涡降水累计量占同时段总降水量62.5%,冷涡降水与同期月降水量年际变化具有很好一致性;东北地区初夏降水与东北冷涡降水eof分解主要模态十分相似,均呈相似的四种空间分布型,即“全区一致偏多”、以东北平原为界限的“东北多西南少”、“东北少西南多”以及“全区一致偏少”。说明东北地区初夏冷涡“累积效应”产生的降水极大影响甚至决定整个初夏东北地区降水多寡及空间分布特征,可总体反映初夏东北地区降水异常分布特征。从而进一步揭示东北冷涡活动的气候学特征。(5)基于多视角刻画的冷涡活动因子序列,结合5-8月东北地区月降水,一方面开展东北地区2012-2014年共计3年的月降水预测应用研究,另一方面将冷涡因子序列纳入fodas降水预测系统中,进行2003-2012年共计10年的降水回报预测检验。降水预测应用结果能够客观反映实况降水的时空分布和降水多寡分布特征,得到较好的预测效果。fodas系统降水回报效果良好,预测结果均能进行稳定的正订正,绝大多数指数订正结果高于系统自身系统订正值。通过预测应用研究,较好体现表征冷涡不同特点的冷涡指数在东北地区降水预测中的不同特征,同时为东北地区降水预测提供定量化指数产品,为进一步开展东北地区月降水预测工作提供一定理论和技术支撑。(6)冷涡活动受上下游阻塞系统的影响显著,阻塞高压活动有利于冷涡的维持和加强。阻高活动位置的不同对冷涡位置强度影响存在差异,二者不同配置所造成的东北地区降水亦存在差异,冷涡与不同类型阻塞形势配置下对我国东北地区降水均为正贡献,且以鄂霍次克海阻高与冷涡共存下更有利于东北地区产生降水。冷涡活动强,副高脊线位置偏南,西风指数偏强,冷涡活动弱,副高脊线位置偏北,西风指数偏弱。冷涡活动偏多年乌山阻高和鄂海阻高活动盛行,乌拉尔山-鄂霍次克海双阻型阻塞形势存在有利于东北冷涡的维持和发展,乌山-鄂海双阻活动在1977年前后发生显著突变,突变后双阻活动天数呈显著减少,突变前(后),乌拉尔山与鄂霍次克海阻塞高压活动呈现同(反)位向变化。双阻活动气候学特征表明,突变后乌山-鄂海双阻特征更强,反映双阻活动强度相对偏强特征。双阻活动能量传播以低层向高层输送为主,突变后,乌拉尔山至鄂霍次克海的能量传播由突变前的向低纬传播为主转为向高纬传播为主,并为双阻间低值系统发展提供能量,即双阻活动有利于东北冷涡系统的维持和发展。
[Abstract]:Necv is high active in high latitude regions of East Asia to cut off the cold, a cold vortex process for 3-5d, is the scale system. However, the frequent process of northeast cold vortex in Northeast Asia, often have an important impact on climate anomaly in eastern China. Even so, at the beginning of the twenty-first Century, Chinese scholars began to study and put forward a clear necv "climate effect" of the scientific problems, enrich the connotation of the necv theory. The northern hemisphere high latitude blocking theory research situation, mostly blocking high mainly. By utilizing the daily precipitation data 1960-2012 national meteorological stations during 1948-2012 NCEP/NCAR reanalysis data and daily meteorological information center provided by the state, mainly from the activities of the necv anomaly as the main body of the first, study how to use the machine number automatic identification method, revealing its activities The characteristics of weather and climate scale, as a basis for further enrich the activities of the "climate effect", and carry out the research and Application on the prediction of monthly precipitation in Northeast Cold Vortex based on factor. Secondly, the number of test results using the same method given Asian Blocking activities; on the northeast cold vortex and blocking configuration, especially focusing on the in high latitude blocking flow pattern (in Ural mountain and the sea of Okhotsk double blocking type) interaction between the two and the northeast cold vortex and its formation, development and extinction mechanism. The main conclusions are as follows: (1) the activities of the necv 5-8 months are 1948-2012 years of weather process, analyze the statistical characteristics, the necv activities based on 3-6d, the main located in 121o-131oE, 48o-53oN interval; necv occurrence frequency and activity days were significantly increased.5-6 and 7-8 months necv activities for high From the main abnormal areas of flat field and special juvenile synthesis in opposite phase distribution, and the phase characteristics in the troposphere, high (200 hPa, 500 h Pa) showed wavetrains characteristics of near hemisphere scale; 5-6 and 7-8 months, and special juvenile necv activities similar difference distribution were synthesized for many years, significant north-south "+, -" wavetrains, positive and negative wave are located in the Northwest Pacific and the Okhotsk Sea and the Bering Sea region, the relative position of the corresponding wave height wind in abnormal years cyclonic and anticyclonic circulation.7-8 Month activities of the necv, Bay Lake to the Okhotsk High and cold vortex in Northeast China many at the same time, the abnormal years, Tony Lake to the Okhotsk High is not popular, the majority occurred in order to prevent high first cold vortex (2). The activities of the necv duration of cold continuous activities based on the strength index of The amount of description, the index has good significance for the characterization of cold vortex process. Cold vortex activity continued strong in May, Ural mountain and Lake Baikal blocking situation significantly, in June the Okhotsk Sea blocking situation significantly, 7 mid high latitude blocking flow is not significant, the August Ural mountain Okhotsk Sea double blocking action is evident. Especially in June, strong cold index the system is deep, concentrated in the upper troposphere, cold heart structure is obvious, with a certain barocline feature; high cold center, with lower temperature trough in the upper level westerly, and present upstream and downstream diversion confluence characteristics, split between showing the Northeast high, southwest low dipole blocking situation; in June the index system with a weak cold vortex, mainly concentrated in the middle and lower troposphere, cold heart structure is not obvious, there is no congestion situation. (3) the geographical distribution characteristics of cold vortex activity based on the circulation The persistent anomaly of the cold vortex persistence is a new definition of generalized "vortex", described by quantitative, generalized "cold" intensity index, the activities of the necv exhibit significant interannual and interdecadal periods of oscillation in the "cold vortex" generalized intensity index, describe the frequent and atmospheric weather process circulation characteristics, and Northeast China in early summer (5-6 months) and summer (7-8 months) has a good corresponding relationship between the cold vortex precipitation distribution. The generalized "vortex" activities of strong (weak), Eurasian mid high latitude circulation features are (not) to necv formation, development and maintenance of 7-8 month, East Asia (not) to form is conducive to the circulation of South northward transport of water vapor. In early summer (not) popular in the Ural mountain blocking situation, summer (not) in the sea of Okhotsk blocking situation; subtropical area is smaller (larger), northward time is late (early), There is (not) to maintain the northeast cold vortex. (4) early summer (5-6 months) necv precipitation accounted for the total rainfall of 62.5%, annual precipitation and precipitation period change cold vortex has good consistency; Northeast summer precipitation and precipitation in the northeast cold vortex decomposition of EOF main mode is very similar, are similar four spatial distribution type, namely "the ones", to the Northeast Plain as the boundaries of the "northeast southwest", "small northeast southwest" and "the little". It has great influence in the northeast area of summer precipitation in cold vortex "cumulative effect" and even determines the whole northeast summer precipitation and the characteristics of spatial distribution, can reflect the overall characteristics of summer precipitation anomaly in Northeast China. In order to further reveal the climatic characteristics of the activities of the necv. (5) based on the multi angle characterizations of the necv activities by sub sequence, combined with 5- The monthly precipitation in August in Northeast China, research and Application on the prediction of monthly precipitation in Northeast China to carry out a total of 3 years 2012-2014 years, on the other hand will be incorporated into the fodas vortex factor sequence precipitation forecast system, rainfall return 2003-2012 years a total of 10 years. The application of prediction of precipitation forecast test can reflect the temporal and spatial distribution of precipitation and precipitation the distribution characteristics and get good prediction results of.Fodas precipitation return to good effect, it can be revised forecast results stable, most index is higher than the revised system of own system correction. Through the application of prediction, better reflect the different characteristics of the different characteristics of the cold vortex characterization of cold vortex index in the precipitation forecast in Northeast China, and Northeast China precipitation forecast provide a quantitative index of the product provides a theoretical prediction to further develop the work of monthly precipitation in Northeast China And technical support. (6) effects of cold vortex activity by the upstream and downstream blocking system significantly, is conducive to maintaining and strengthening the high cold vortex obstruction. Different blocking activities influence on the position of the cold vortex position of strength, the two northeast precipitation caused by different configuration are also different, and different types of vortex blocking configuration the Northeast China precipitation are positive contribution, and the Okhotsk High and cold vortex in Northeast China under the coexistence of more conducive to produce precipitation. Cold vortex activity is strong, the position of subtropical high ridge line south westerly strong, cold vortex activity weak, ridge line of the subtropical high North westerly index. The weak partial Ukraine necv activities for many years blocking high and the Okhotsk High popular activity, maintenance and development of Ural mountain and the sea of Okhotsk double blocking blocking situation is conducive to the northeast cold vortex, Wushan - e sea double blocking activity in 1977 before and after the occurrence. The mutation, mutation after double blocking activity days was significantly reduced, the mutation before (after), Ural mountain and the Okhotsk High activity showed the same orientation changes. (trans) showed that the double mutant resistance activity climatology, Wushan - Hubei haishuang resistance characteristics is stronger, reflecting relatively strong strength of double movable double features. Stop activity energy spread in low level to high level transportation, mutation, energy spread of Ural mountain to the sea of Okhotsk by mutations of the former to the low latitude to high latitude spread mainly to spread, and double resistance between low energy system development, maintenance and development of double resistance activities conducive to the northeast cold vortex system.

【学位授予单位】：兰州大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P461.2

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