SST variations of the Kuroshio from AVHRR observation   总被引：1，自引：0，他引：1  

张彩云  陈戈 《中国海洋湖沼学报》2006,24(4):345-351

1 INTRODUCTION The Kuroshio Current (KC), being the western boundary current in the North Pacific subtropical gyre, is the second strongest current in the world af- ter the Gulf Stream and is famous as a strong and fast flow. KC plays an important role in…  相似文献   

PRECIPITATION PATTERNS IN FLOOD SEASON OVER CHINA ASSOCIATED WITH THE EL NI■O/SOUTHERN OSCILIATION     

钱步东 《中国地理科学(英文版)》1997,(3)

I.I~IOXENds(EINabs/SouthernOscillation)eventsaretheintensivesignalsofair-seainteractionintropicalarea.PlentyOfresultsfromdifferentresearchersshoWthattheENdssignalcanbedetectedoninterannualvallationsoflargescaleatmOSPhericcirculationandclimateregimeSovermostpartsoftheworld.SeveralkindsofrelationShipbetweenENdsandprecipitationoverChinahavebeenrevealedbydifferentreSearcherS,buttherearemanydifferencesamongthepublishedreSults.Itmayberesulted*fromthatdifferentreSearchersuseddifferentindic…  相似文献   

Precipitation patterns in flood season over China associated with the El Niño/Southern Osciliation     

Budong Qian 《中国地理科学(英文版)》1997,7(3):220-228

The precipitation patterns in flood season over China associated with the El Niño/Southern Oscillation (ENSO) are investigated, especially in the eastern China, using the rather long period rainfall data in this century. The results show that there were remarkable differences between the precipitation patterns in flood seasons of ENSO warm phase (El Niño year) and cold phase (La Niña year), as well as between the patterns in El Niño years and their following years. The most parts of China received below normal rainfall in flood season of the onset years of El Niño events, but the coastal area of Southeast China received above normal amounts. Comparatively, the most parts of China received above normal rainfall in flood season of the following years of El Niño events, but the eastern part of the reaches among the Huanghe (Yellow) River, the Huaihe River and the Haihe River, and the Northeast China received less. During ENSO cold phase, the reaches of the Changjiang (Yangtze) River and the North China received more amounts than normal rainfall in flood season of the onset years of La Niña events, and the other regions of China received less. In the following years of La Niña events, the coastal area of the Southeast China, the most part of the Northeast China and the regions between the Huanghe River and the Huaihe River received more precipitation during flood seasons, but the other parts received below normal precipitation.  相似文献   

Global impact of a climate treaty if the Human Development Index replaces GDP as a welfare proxy     

Jeroen C. J. M. van den Bergh 《Climate Policy》2018,18(1):76-85

This study explores the implications of shifting the narrative of climate policy evaluation from one of costs/benefits or economic growth to a message of improving social welfare. Focusing on the costs of mitigation and the associated impacts on gross domestic product (GDP) may translate into a widespread concern that a climate agreement will be very costly. This article considers the well-known Human Development Index (HDI) as an alternative criterion for judging the welfare effects of climate policy. We estimate what the maximum possible annual average increase in HDI welfare per tons of CO₂ would be within the carbon budget associated with limiting warming to 2°C over the period 2015–2050. Emission pathways are determined by a policy that allows the HDI of poor countries and their emissions to increase under a business-as-usual development path, while countries with a high HDI value (>0.8) have to restrain their emissions to ensure that the global temperature rise does not exceed 2°C. For comparison, the well-known multi-regional RICE model is used to assess GDP growth under the same climate change policy goals.

Policy relevance

This is the first study that shifts the narrative of climate policy evaluation from one of GDP growth to a message of improving social welfare, as captured by the HDI. This could make it easier for political leaders and climate negotiators to publicly commit themselves to ambitious carbon emission reduction goals, such as limiting global warming to 2°C, as in the (non-binding) agreement made at COP 21 in Paris in 2015. We find that if impacts are framed in terms of growth in HDI per t CO₂ emission per capita instead of in GDP, the HDI of poor countries and their emissions are allowed to increase under a business-as-usual development path, whereas countries with a high HDI (>0.8) must control emissions so that global temperature rise remains within 2°C. Importantly, a climate agreement is more attractive for rich countries under the HDI than the GDP frame. This is good news, as these countries have to make the major contribution to emissions reductions.  相似文献   

1951—2015年进入东海的台风频数及登陆点的变化          下载免费PDF全文

陆晓婕  董昌明  李刚 《大气科学学报》2018,41(4):433-440

利用日本气象厅提供的西北太平洋台风最佳路径观测资料,选取东海海区为研究范围,统计处理1951—2015年台风各要素资料,研究进入东海海区的台风频数、台风登陆点位置、台风频数及登陆点位置与太平洋年代际振荡（Pacific Decadal Oscillation,PDO）及ENSO的关系、影响台风生成和移动的因素等。结果表明：1）每年的7—9月为东海海区的台风高发季,其中8月最高,登陆台风也有相似趋势。2）进入东海海域的台风频数存在较明显的年际和年代际变化趋势。当PDO处于暖位相时,台风频数较小且有上升趋势,反之亦然。El Niño年进入东海海区的台风频数较常年减少,反之亦然。Niño3.4指数与台风频数整体上为负相关关系,相关系数为-0.32且通过90%置信度检验。3）进入东海海域的台风登陆点纬度变化较大,处于24~36°N之间,且有年代际变化特征。当PDO处于暖（冷）位相时,台风登陆点偏北（偏南）且有向北（南）移动的趋势。而登陆点纬度与ENSO的关系较为复杂。4）西北太平洋副热带高压的位置和强度是引起台风频数及登陆点位置变化的主要原因之一。当PDO处于冷位相时,西北太平洋副热带高压强度偏弱,且副高中心向东向北方向移动,导致进入东海的台风频数偏多,且台风登陆点偏北,反之亦然。  相似文献   

ENSO与西北太平洋强TC相关关系年代际变化研究          下载免费PDF全文

陶丽  蓝玉峰  孔承承 《大气科学学报》2018,41(5):596-607

利用美国联合台风警报中心(Joint Typhoon Warning Center,JTWC),中国气象局(China Meteorological Administration,CMA)上海台风所,日本气象厅(Japan Meteorological Agency,JMA)的台风最佳路径资料以及美国NCAR/NCEP再分析资料等,深入研究厄尔尼诺—南方涛动(El Ni1o-Southern Oscillation,ENSO)与西北太平洋强热带气旋(Tropical Cyclone,TC),即1 min最大风速大于等于114 kn相关关系的变化。结果表明,ENSO与热带西北太平洋(Western North Pacific,WNP)强TC频数之间的相关关系存在明显年代际变化。在1960—1971年期间(前一阶段),强TC年频数与Ni1o3. 4(11月—次年1月平均)相关性较弱;而在1983—2014年期间(后一阶段)两者的相关性则为强的正相关。并且强TC的年频数、生命史以及生成位置在后一阶段El Ni1o和La Ni1a年之间的差异相比前一阶段都有明显的增大。进一步分析发现:热带太平洋海温异常(Sea Surface Temperature Anomaly,SSTA)的西移是造成后一阶段Ni1o3. 4指数与强TC年频数相关性提高的关键因素。在后一阶段的El Ni1o(La Ni1a)年,SSTA的西移使得WNP东南象限的相对湿度明显增加(减少),从而有利于(不利于) TC在此象限生成。又因为位于东南象限的TC比较容易发展成强TC,因此导致后一阶段的El Ni1o(La Ni1a)年有更多(更少)的强TC在西北太平洋的东南象限生成。  相似文献   

超强厄尔尼诺事件对中国东部春夏季极端降水频率的影响   总被引：2，自引：0，他引：2  

刘明竑  任宏利  张文君  任鹏飞 《气象学报》2018,76(4):539-553

利用中国国家气象信息中心提供的中国地面逐日降水0.5°×0.5°格点数据集,研究了超强厄尔尼诺事件衰减年春、夏季中国东部极端降水发生概率的变化,并通过诊断超强厄尔尼诺自身及其衍生模态各自的水汽输送和垂直运动特征,探讨了超强厄尔尼诺事件对中国东部极端降水的影响机制。结果表明,超强厄尔尼诺事件衰减年春季,整个中国东部尤其是江淮以北地区,极端降水事件发生概率显著增大。同年夏季,长江流域极端降水发生概率比常规年份高出近1倍,而在华南和华北地区则相对减小。诊断分析显示,春季超强厄尔尼诺自身及其与热带太平洋地区年循环相互作用衍生出的组合模态（C-mode）均对降水的环流背景影响显著,热带太平洋西北部低空存在强盛的反气旋性异常环流,导致大量水汽在中国东部汇聚并上升,有利于该地区极端降水事件的发生。夏季,厄尔尼诺事件已经消亡,但与C-mode影响相关联的西北太平洋异常反气旋环流仍然存在,长江流域维持极端降水事件发生的有利条件。此外,研究也显示,超强厄尔尼诺事件衰减年春、夏季中国东部对流层中上层持续有异常经向风活动,频繁的南北冷暖气流交汇可能导致强对流事件发生次数增多,这也为该区域极端降水的频发提供了支持。   相似文献   

两种形态ENSO对南半球热带外气候变化特征的影响          下载免费PDF全文

万伟杰张召儒  刘海龙周朦 钟贻森 《极地研究》2018,30(4):376-390

本研究利用1979—2012年欧洲中期天气预报中心(ECMWF)的ORAP5(Ocean Reanalysis Pilot 5)海洋/海冰再分析资料和ERA-Interim气象再分析资料,采用回归分析方法,分1979—1998年和1999—2012年两个时间段探讨了南半球热带外地区气候变化对两种不同形态ENSO的响应特征。结果表明,南半球热带外区域气候在1999年前后两个时段对ENSO的响应表现出了较大的年代际变化特征。1979—1998年南半球热带外气候变量对Nio3指数在时间上的相关性和空间上的响应强度都普遍大于Nio4指数,说明这一时段东部型ENSO对南半球热带外区域气候变化的影响要更强一些。在1999—2012年,不同形态ENSO与气候变量的相关性大小并无明显的规律,而且空间响应场的差异性并不大。海平面气压、风场和气温对ENSO变化的响应在南半球冬季表现最为强烈,在夏季最弱。三者在1999—2012年秋季对Nio3指数和Nio4指数的响应场中出现了纬向三波数结构。1999—2012年冬季,有异于海平面气压和风场,在罗斯海和阿蒙森海海域海表气温对Nio4变化的正响应明显强于对Nio3的响应,该特征在混合层温度中也有体现,表明海表气温随ENSO的变化受海洋特征变化影响较大。混合层深度和混合层温度的响应场之间存在很大的相关性,混合层温度响应在秋季表现最强,春季最弱,混合层深度响应与之相反。在1979—1998年,海冰密集度对不同Nio指数变化的响应差异主要出现在海冰结冰季节,而海冰厚度对不同Nio指数变化的响应差异在夏季表现较强。海冰密集度和厚度对Nio3变化响应的年代际差异在秋冬季节更加明显,对Nio4变化响应的年代际差异在秋、冬、春季都较明显。  相似文献   

洞庭湖流域降水同位素与ENSO关系研究   总被引：1，自引：1，他引：0  

黄一民  宋献方  章新平  何清华  韩青  李强 《地理科学》2017,37(5):792-798

基于洞庭湖流域内长沙市2010年1月至2012年12月降水事件、GNIP(Global Network for Isotopes in Precipitation)长沙站1988~1992年月降水同位素资料及ENSO（厄尔尼诺/拉尼娜和南方涛动）的2个常用指标（南方涛动指数SOI和Nino3区海面温度SST）,分析了流域降水同位素与ENSO关系。结果表明：洞庭湖流域降水中δ¹⁸O与降水量、气温在日、月尺度上均呈负相关且只有月度上与降水量的负相关不显著。洞庭湖流域降水中δ¹⁸O与ENSO的SST指标则呈显著正相关。ENSO对洞庭湖流域降水同位素的影响机制可能如下：春季,La Nina年源自西太平洋的东南风强盛,其转向为西南风的区域达到印度洋,而El Nino年,东南风转向为西南风的发生区域位于印度洋以东,前者有利于挟带印度洋远源水汽向中国东部区域输送,进而造成降水同位素的贫化;夏季,La Nina年印度洋水汽输送在中国南海转为经向继而向北延伸,而El Nino年,源自印度洋的水汽沿纬向穿过南海,在东海转向往北延伸,后者有利于挟带西太平洋的近源水汽输送到中国东部季风区,进而引起降水同位素的富集。  相似文献   

GIS diffusion in Uganda     

Sami Eria  Robert B. McMaster 《International journal of geographical information science》2017,31(5):884-906

Despite myriad studies having been carried out on the diffusion of geographical information systems (GIS) technology, only a limited number have been done within the context of developing countries. This paper addresses the research question, how did the diffusion of GIS technology occur in Uganda? Mixed methods were used for data collection, and analysis was performed using a theoretical framework called the diffusion of innovations (DOI). The results of the study showed that the adoption of GIS by institutions in Uganda occurred in a classic diffusion pattern consistent with diffusion theory. Adoption of GIS was promoted by its relative advantage over, and compatibility with, existing technologies. It was characterized by both heterophilous and homophilous communication channels, and influenced by change agents and champions. Its rate of adoption followed an S-shaped diffusion curve, and was hampered by bureaucracy, and patronage-based societal norms. This study makes a contribution to literature on GIS diffusion in developing countries.  相似文献