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陆面过程研究的进展 总被引：17，自引：0，他引：17
孙菽芬 《沙漠与绿洲气象(新疆气象)》2002,25(6):1-6
文中首先阐述陆面过程研究的必要性和复杂性。然后，对陆面过程研究的任务和内容作了较详细的说明，进而对陆面过程研究的进展现状和未来发展方向作了讨论。 相似文献
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长春市逆温层及其对大气污染的影响分析 总被引：1，自引：0，他引：1
本文根据长春市气象站１９９３～１９９５年每日０７时和１９时的高空观测资料，对有关送温层的数据作了统计和研究，并在此基础上对长春市上空边界层内逆温分布的类型和变化规律作了分析论证，这对城市大气污染规律的研究具有重要意义。 相似文献
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本文对分布函数概念,对已经找到的重要的气象中的分布函数,对如何从熵原理去理解它们作了综合介绍.文中还对如何将此用于数值天气预告、气候变迁研究作了分析. 相似文献
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大气非平衡运动的演变与跳跃式暴雨过程 总被引：2，自引：0，他引：2
对１９９４年６月２４￣２６日长江中上游地区出现的一次跳跃式暴雨过程作了诊断研究，结果指出，对流层高层地转不平衡运动及低空急流的变化是造成降水系统生消演变的重要因素，并对地面天气系统的发生发展作了较详细的分析研究。 相似文献
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21世纪西北太平洋台风变化预估 总被引：3，自引：1，他引：2
对近年多个气候模式考虑不同的人类排放情景作了总结,并对21世纪西北太平洋台风变化作了预估。研究表明,集成多个气候模式考虑人类排放情景,预估到21世纪后期,西北太平洋年总编号台风数可能减少,但强台风数及其降水和风速可能增强。需要强调的是,台风的长期预估是极其困难的,存在极大的不确定性,有待作更深入的研究。 相似文献
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热带气旋强度变化的cliper预报方案 总被引：1，自引：0，他引：1
—、前言对于热带气旋强度变化和台风的发生发展,前人已作了大量的分析和研究。但是,对于台风和热带气旋强度变化的客观预报方祛,研究得并不多。在这方面做得较早的有RL·Elsbrry等人,他们建立了预报台风和热带气旋强度的24、48和72小时变化的回归方程。近几年来林有任和笔者分别用统计和动力统计的方法对台风和热带气旋的强度变化的预报作了研究,并得到了客观预报方程。本文将用气候持续性方案对台风和热带气旋的强度变化作一些研究分析。 相似文献
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<p>PARTITION OF SEASON BASED ON MULTIELEMENTS AND THE DECADAL CHANGE OF SEASON DURATION IN CHINA</p>
<p>Using the multielements similarity measurement method and 1950–C2017 NCEP/NCAR gridded daily reanalysis datasets, we analyzed season duration in China during 1950–C2016, and we defined the element with maximum absolute sensitivity as the key impact element at each point using the sensitivity analysis method. The decadal change of season duration and its key impact element before and after 1980 were studied. The results indicated obvious meridional and zonal differences in the distribution of season duration for the 67-year average, and that the key impact element has the same distribution characteristics as season duration. In addition, complementary relationships were found between the durations of spring and summer, autumn and winter, and the cold and warm seasons. Of those, the complementary relationship between the durations of spring and summer was strongest and the regions of complementarity were numerous. The complementary regions of autumn and winter durations were found mainly in western China. In the cold and warm seasons, the complementary regions were widespread and the complementary relationship was generally weak. Comparison of the periods before and after 1980 revealed an east–Cwest difference in the interdecadal variation of season duration. Interdecadal variation in spring and summer was found concentrated in northern and western regions, while that in autumn and winter was concentrated in the western region. Areas of significant interdecadal variation of the key elements were found concentrated in northern and western regions, corresponding well with the areas of significant interdecadal variation of season duration.</p> 相似文献
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利用1961—2020年中国区域2089个地面观测站资料,分析了1991—2020年和1981—2010年新、旧气候态下,平均气温、最高气温、最低气温和降水量等变量的空间变化特征,探讨对气候距平值、极端事件等评估结果的影响。结果表明：新气候态下,全国三类气温年和季节平均均一致升高,年降水增加,空间上气温偏高（低）、降水偏多（少）的特征将弱（强）化;华北东部、华东中部和北部以及青海西南部的年平均风速和日照时数距平增加;极端高温年减少,低温年增多,其中平均气温和最低气温受到的影响较最高气温更大;夏季南北方两条雨带极端强降水年的发生概率降低,冬季东北中部和南部、华北、华东北部、西北东部极端弱降水年概率显著增加;全国超过一半的站点极端日高温、低温和强降水事件的历史频次发生改变;新气候态还减弱了极端日高温事件的增速,加快了极端日低温事件的降速。 相似文献
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欧亚冬季温带反气旋活动的气候特征 总被引：1，自引：0，他引：1
利用NCEP/NCAR再分析数据,通过判定和追踪温带反气旋的客观方法统计分析了1948-2013年欧亚地区冬季温带反气旋的生成、消亡、移动、生命史、强度等气候特征。结果表明,反气旋的主要源地位于蒙古高原、伊朗及其周边地区、地中海沿岸、中西伯利亚、波罗的海西北部、俄罗斯东北部等地,其中,蒙古高原和伊朗等地也是强反气旋最主要的源地。反气旋活动的大值分布区和反气旋生成的大值中心分布十分相似,主要活跃区对应低空平均经向温度梯度大值区和高空脊前。除源于蒙古高原和西伯利亚东北部的强、弱反气旋的移动距离差别不明显外,其他地区的反气旋移动距离与强度有密切关系。持续1-2 d的反气旋占总数的44.2%,而只有3.2%的反气旋生命史超过一周,且强反气旋比弱反气旋更易持续较长时间。 相似文献
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以揭示中国冬、夏季气温、降水之间的同期耦合时空特征为例,比较了SVD与MEOF分析所得主要正交模的相关关系及均衡性,论证了SVD方法在揭示两个要素场序列互相关关系上的优越性。结果表明:1) SVD的分解对象仅包含反映两种要素场相关关系的信息,而MEOF还包含了两个要素场各自的自相关信息,前者分解对象更纯粹。2) MEOF和SVD揭示的气温和降水空间耦合模态正负异常分布大致相似,但相较SVD所揭示的耦合模态,MEOF分析的冬、夏季气温、降水主要正交模存在不均衡现象,即一个主要MEOF正交模往往侧重描述两种异常要素场中的一种,这种差异在冬季尤为突出。SVD方法揭示了中国冬、夏季同期气温、降水间局域高温少降水或低温多降水是二者主要异常配置,且相关性夏强冬弱。3)比较SVD、MEOF方法同序正交模的相关系数和均衡度发现,SVD多数正交模的相关系数较MEOF的更大、更稳定,且均通过显著性检验,MEOF的冬季部分正交模相关系数未通过显著性检验; SVD主要正交模的均衡性冬季优于MEOF分析、夏季优于(第一模态)或者接近于(第二、三模态) MEOF分析。故SVD方法是揭示两要素之间耦合关系的更好方法。 相似文献
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周智翔 《热带气象学报(英文版)》2009,15(1):1-12
On the basis of a comprehensive literature review and data analysis of global influenza surveillance, a transmission theory based numerical model is developed to understand the causative factors of influenza seasonality and the biodynamical mechanisms of seasonal flu. The model is applied to simulate the seasonality and weekly activity of influenza in different areas across all continents and climate zones around the world. Model solution and the good matches between model output and actual influenza indexes affirm that influenza activity is highly auto-correlative and relies on determinants of a broad spectrum. Internal dynamic resonance; variations of meteorological elements (solar radiation, precipitation and dewpoint); socio-behavioral influences and herd immunity to circulating strains prove to be the critical explanatory factors of the seasonality and weekly activity of influenza. In all climate regions, influenza activity is proportional to the exponential of the number of days with precipitation and to the negative exponential of quarter power of sunny hours. Influenza activity is a negative exponential function of dewpoint in temperate and arctic regions and an exponential function of the absolute deviation of dewpoint from its annual mean in the tropics. Epidemics of seasonal influenza could be deemed as the consequence of the dynamic resonance and interactions of determinants. Early interventions (such as opportune vaccination, prompt social distancing, and maintaining incidence well below a baseline) are key to the control and prevention of seasonal influenza. Moderate amount of sunlight exposure or Vitamin D supplementation during rainy and short-day photoperiod seasons, more outdoor activities, and appropriate indoor dewpoint deserve great attention in influenza prevention. To a considerable degree, the study reveals the mechanism of influenza seasonality, demonstrating a potential for influenza activity projection. The concept and algorithm can be explored for further applications. 相似文献
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By using the gauged rainfall in 160 stations within mainland China and the NCEP/NCAR reanalysis data, the impacts of anomalous SST in Kuroshio and its extension on precipitation in Northeast China were investigated. The results show that a difference in the meridional circulation such as the East Asia/Pacific teleconnection pattern(EAP)may be responsible for the difference in rainfall between 1998 and 2010. In comparison with 1998, the anomalous meridional circulation pattern in 2010 shifted northeastward, and then the western subtropical high, the mid-latitudinal trough and the northeastern Asia blocking high also shifted northeastward, causing intensified convergence of the cold and warm air masses at the southern region and thus more rainfall in the southwestern region and less in the northwestern region. In 1998, the anomalous cyclone, one component of the meridional pattern, located at the Songhuajiang-Nengjiang River basin, resulted in more rainfall in the majority of the area. The results of observation and the model show that the difference in SSTA in Kuroshio and its extension under the background of different El Ni觡o events is the key point:(1) The anomalous warmth moved westward from the mid-Pacific to the east of the Philippine Sea during the central event, which led the heat resources shifting to the northeast in 2010; subsequently, a shift occurred to the north of the anomalous ascent and decent, followed by a warm SSTA in the region of Kuroshio's extension in 2010 and Kuroshio in 1998.(2) The warm SSTA in the Kuroshio extension causing the Rossby wave activity flux strengthened in 2010, and then the westerly jet shifted northward and extended eastward. A warm SSTA in Kuroshio and cold SSTA in its extension in 1998 caused the westerly jet to shift southward and weaken. As a result,the anomalous anticyclone and cyclone shifted northward in 2010, and the blocking high also shifted northward. 相似文献
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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
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冰冻圈变化的适应研究是冰冻圈科学领域的新兴研究方向,是当今自然科学与社会科学交叉融合跨学科集成研究的典型代表。起步于2007年的中国冰冻圈变化适应研究,经历了早期的探索,研究重点由评价脆弱性发展为量化冰冻圈变化的影响,形成以影响/风险—脆弱性—适应全链条的完善的研究体系,研究方法突破传统的指标体系赋权法的不足,初步实现了定量化,有机结合影响/风险、脆弱性、适应三方面的研究结果,使冰冻圈变化的适应措施由偏重宏观性、普适性开始转向更有针对性。未来中国冰冻圈变化的适应研究应拓展、完善和深化现有的理论体系,构建冰冻圈与社会经济耦合模型,科学量化冰冻圈全要素变化的影响,建立不同利益相关者与科学家共同参与的研究新模式,科学有效应对与适应冰冻圈变化及其影响。 相似文献
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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
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基于1960—2017年观测数据分析了中国东部降水极端特性的地区差异、季节和气候学特征及变化格局,探讨了与全球变化和区域气候变率的关联性。结果表明,极端性降水的演化与降水均值或总量的气候型态、降水集中性和持续性密切关联,尤其雨带迁移和雨型演替是影响极端性降水地区差异与时空演变的根本因素。气候变化背景下,中国东部极端性降水强度和频次变化存在较好的协同一致性,近60年来在长江以南,强度加大的地区极端性降水亦趋于频发。同时,两者季节特征和地区差异明显。春季东北地区及华北北部极端性降水强度和频次均有明显增加。近60年来夏季极端性降水强度和频次的趋势变化在长江以南均以增加为主,以北以下降为主。秋季极端性降水强度和频次在华北地区亦呈增加趋势。冬季华南和江南地区极端性降水强度和频次趋势变化均以增加为主。华北地区及以北和内蒙古的西部冬季极端性降水强度增加显著,但频次变化不明显。而东北地区北部冬季极端性降水在强度减小的情形下,其频次仍趋显著增加。特别是中国降水主要集中在夏季,自1980年代以来中国东部夏季多雨带南移,雨型以北方型和中间型占优,转换为以长江型和华南型为主,多雨带的极端性降水群发性强,影响指数显著增加。此外,太平洋年代际振荡(PDO)暖位相及ENSO暖事件期间,长江以北夏季极端性降水的影响指数会显著降低。而东亚夏季风的减弱则有利于长江中下游等地区夏季极端性降水的频发和群发,极端性降水强度加大,其影响的危险性趋于增强。 相似文献