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1.
北极海冰融化影响东亚冬季天气和气候的研究进展以及学术争论焦点问题 总被引：3，自引：1，他引：2
北极历来是影响东亚冬季天气、气候的关键区域之一。北极表面增暖要比全球平均快2~3倍,即所谓北极的放大效应。随着全球增暖的持续以及北极海冰的持续融化,北极的生态环境正在发生显著的变化,进而可能对北半球中、低纬度的天气、气候产生影响。本文概述了有关北极海冰融化影响冬季东亚天气、气候的主要研究进展,特别是自2000年以来,北极海冰异常偏少影响东亚冬季气候变率以及极端严寒事件的可能途径、存在的科学问题,以及学术界的争论焦点。秋、冬季节是北极海冰快速形成时期,此时北极海冰对大气环流的影响要强于大气对海冰的影响。近二十年来的研究结果表明,北极海冰异常偏少,不仅影响北冰洋局地的气温和降水变化,而且通过复杂的相互作用和反馈过程,对北半球中、低纬度的天气、气候产生影响。北极海冰通过以下两个可能机制来影响东亚冬季的天气、气候:（1）北极海冰的负反馈机制;（2）由海冰异常偏少引起的平流层-对流层相互作用机制。秋、冬季节北极海冰持续异常偏少,特别是,巴伦支海-喀拉海海冰异常偏少,既可以加强冬季西伯利亚高压（东亚冬季风偏强）,也可以导致冬季风偏弱。导致海冰影响不确定性的部分原因是:（1）夏季北极大气环流状态影响北极海冰异常偏少对冬季大气环流的反馈效果;（2）冬季大气环流对北极海冰异常偏少响应的位置、强度不同造成的。秋、冬季节北极海冰持续异常偏少,在适宜的条件下（例如,前期夏季北极大气环流的热力和动力条件,有利于加强北极海冰偏少对冬季大气的反馈作用）,可以激发出有利于冬季亚洲大陆极端严寒过程的大气环流异常。目前学术界争论焦点主要集中在以下两个方面:（1）关于北极增暖、北极海冰融化对中纬度区域影响的争论;（2）关于1980年代后期以来,冬季欧亚大陆表面气温呈现降温趋势的原因。目前,有关北极海冰融化影响冬季欧亚大陆次季节变化以及极端天气、气候事件的过程和机制,我们认知非常有限,亟需开展深入细致的研究。 相似文献
2.
利用ERA-interim的再分析资料和英国大气数据中心的海冰密集度资料,通过复矢量经验正交分析方法(CVEOF),本文研究了自1979-2016年37个冬季(12月1日至次年2月28日)共3330 d对流层中层500 hPa欧亚盛行天气型主要时空变化特征及其与近年来北极对流层中、低层增暖异常和北极海冰减少的可能联系。结果表明,CVEOF1解释了总异常动能的15. 82%,其两个子模态空间型分别表现为三极子型(0°和180°位相)和偶极子型(90°和270°位相)。其中,180°和270°位相的天气型发生时,冬季北极对流层中、低层偏暖,盛行暖北极-冷欧亚的大气环流形势。前期秋季从巴伦支海海域以东到波弗特海海域的海冰密集度(SIC)异常偏少可能是其影响因素之一。近年来这两个位相(180°和270°位相)的发生频次逐渐增多,与冬季频发的极端低温事件有紧密联系。在2005/2006年和2011/2012年冬季的冷事件中,180°和270°位相的发生频次明显偏多。因此,秋季从巴伦支海海域以东到波弗特海海域的SIC偏少,冬季北极对流层中、低层异常偏暖,有利于180°和270°位相天气型盛行,可能是导致冬季极端天气事件频发的主要原因之一。 相似文献
3.
Arctic sea ice and Eurasian climate: A review 总被引：12，自引：0，他引：12
GAO Yongqi SUN Jianqi LI Fei HE Shengping Stein SANDVEN YAN Qing ZHANG Zhongshi Katja LOHMANN Noel KEENLYSIDE Tore FUREVIK SUO Lingling 《大气科学进展》2015,32(1):92-114
The Arctic plays a fundamental role in the climate system and has shown significant climate change in recent decades,including the Arctic warming and decline of Arctic sea-ice extent and thickness. In contrast to the Arctic warming and reduction of Arctic sea ice, Europe, East Asia and North America have experienced anomalously cold conditions, with record snowfall during recent years. In this paper, we review current understanding of the sea-ice impacts on the Eurasian climate.Paleo, observational and modelling studies are covered to summarize several major themes, including: the variability of Arctic sea ice and its controls; the likely causes and apparent impacts of the Arctic sea-ice decline during the satellite era,as well as past and projected future impacts and trends; the links and feedback mechanisms between the Arctic sea ice and the Arctic Oscillation/North Atlantic Oscillation, the recent Eurasian cooling, winter atmospheric circulation, summer precipitation in East Asia, spring snowfall over Eurasia, East Asian winter monsoon, and midlatitude extreme weather; and the remote climate response(e.g., atmospheric circulation, air temperature) to changes in Arctic sea ice. We conclude with a brief summary and suggestions for future research. 相似文献
4.
Reporting the links (or lack of them) between human-induced climate change and individual extreme weather events poses a series of challenges for journalists. In recent years, their task has become more complicated by the increase in the number of extreme event attribution (EEA) studies which assess how climate change is affecting the intensity or likelihood of specific weather events. Such studies are complex, contain uncertainties, and can be difficult to explain to a lay audience. Previous scholarship has largely focused on media coverage of extreme events in developed countries, and on the volume of coverage of the links to climate change, without examining references to EEA studies. To help fill this gap, we take India as our case study, and the mainstream media coverage there of the Chennai rainfall event and the heat wave in Andhra Pradesh in 2015. Both events were subject to attribution studies. Amongst our findings are that journalists most commonly used generic phrases to describe the link between such events and climate change; politicians and NGOs often ‘blamed’ climate change without reference to the science; and relevant EEA studies were seldom quoted. Based on our findings, we make some preliminary recommendations for training journalists in India and elsewhere to support accurate reporting of extreme events and their possible linkages to climate change. 相似文献
5.
Mapping the shadow of experience of extreme weather events 总被引：1，自引：1，他引：0
Peter D. Howe Hilary Boudet Anthony Leiserowitz Edward W. Maibach 《Climatic change》2014,127(2):381-389
Climate change will increase the frequency and/or intensity of certain extreme weather events, and perceived experience with extreme weather may influence climate change beliefs, attitudes, and behaviors. However, the aspects of extreme events that influence whether or not people perceive that they have personally experienced them remain unclear. We investigate (1) the correspondence of reported experience of extreme weather events with documented events, and (2) how characteristics of different extreme events shape the geographic area within which people are likely to report they have experienced it—the event’s perceived “shadow of experience.” We overlay geocoded survey responses indicating personal experience with hurricanes, tornadoes, and drought—from a 2012 nationally representative survey (N?=?1,008) of U.S. residents—on maps of recorded event impacts. We find that reported experiences correspond well with recorded event impacts, particularly for hurricanes and tornadoes. Reported experiences were related to event type, proximity, magnitude and duration. The results suggest locations where disaster preparedness efforts and climate change education campaigns could be most effective after an extreme weather event. 相似文献
6.
500 hPa位势高度场极端天气事件的NCEP集合概率预报效果分析 总被引：1，自引：0，他引：1
基于百分位方法,首先通过构建气候等概率区间得到了位势高度场极端天气事件区分方法,并给出了相应的预报结果检验评价方案;以此为基础,对2003年夏季亚欧区域的500hPa位势高度场极端天气事件的NCEP集合概率预报效果进行了深入分析,得到如下结论：1）分析时段和区域内的极端事件的发生频率比气候平均状况略偏高。NCEP集合预报系统对异常偏低的极端事件的预报易偏高,但相对比较可靠;对相对异常偏高极端事件的预报频率随着预报时效的增大而减小,时效小于3d时预报频率偏高,时效大于5d时显著偏低,预报可靠性相对差一些。2）EV（economic value,经济价值）分析表明,NCEP集合预报系统对偏高（低）极端事件的概率预报效果明显高于正常天气事件。3）预报命中率分析表明,在高概率阈值下,预报命中率较低,这与预报系统在部分个例中的不发散有关。随着概率阈值的降低,预报命中率稳步提高,说明集合成员的发散使之可以覆盖实况可能出现的区间,从而得到更好的预报效果。 相似文献
7.
This paper reviews recent progress in climate change attribution studies. The focus is on the attribution of observed long-term changes in surface temperature, precipitation, circulation, and extremes, as well as that of specific extreme weather and climate events. Based on new methods and better models and observations, the latest studies further verify the conclusions on climate change attribution in the IPCC AR5, and enrich the evidence for anthropogenic influences on weather and climate variables and extremes. The uncertainty of global temperature change attributable to anthropogenic forcings lies in the considerable uncertainty of estimated total radiative forcing due to aerosols, while the uncertainty of precipitation change attribution arises from the limitations of observation and model simulations along with influences from large internal variability. In terms of extreme weather and climate events, it is clear that attribution studies have provided important new insights into the changes in the intensity or frequency of some of these events caused by anthropogenic climate change. The framing of the research question, the methods selected, and the model and statistical methods used all have influences on the results and conclusions drawn in an event attribution study. Overall, attribution studies in China remain inadequate because of limited research focus and the complexity of the monsoon climate in East Asia. Attribution research in China has focused mainly on changes or events related to temperature, such as the attribution of changes in mean and extreme temperature and individual heat wave events. Some progress has also been made regarding the pattern of changes in precipitation and individual extreme rainfall events in China. Nonetheless, gaps remain with respect to the attribution of changes in extreme precipitation, circulation, and drought, as well as to the event attribution such as those related to drought and tropical cyclones. It can be expected that, with the continual development of climate models, ongoing improvements to data, and the introduction of new methods in the future, climate change attribution research will develop accordingly. Additionally, further improvement in climate change attribution will facilitate the development of operational attribution systems for extreme events, as well as attribution studies of climate change impacts. 相似文献
8.
平流层异常下传对2009年12月北半球大范围降雪过程的影响 总被引：2，自引：2，他引：0
2009年12月北半球中纬度出现大范围持续低温、暴风雪等天气。采用NCEP／NCAR再分析资料研究了平流层AO（Arctic Oscillation,北极涛动）异常信号下传的特征及其对本次极端气候事件的影响,并讨论了与平流层异常信号下传相关的行星波活动。结果表明：1）与此次极端气候事件相联系的负位相A0异常11月首先发生在平流层,维持将近1个月后于12月初开始下传,并且迅速传至地面。12月整个对流层的位势高度及温度在极区附近出现强的正异常,而中纬度地区则为负异常。2）平流层AO异常信号下传后,地面出现有利于低温降雪过程的环流异常。12月上旬,亚洲大陆东部及北美大陆西部出现异常偏北风,造成了俄罗斯、北美西部大面积负的温度异常;12月中下旬,欧洲大陆盛行偏西北气流,同时蒙古高压增强,欧亚大陆北部包括中国北方出现大片负的温度异常。3）在此次极端气候事件之前,北半球高纬度地区有异常强的行星波上传至平流层,导致平流层出现负位相的AO异常,并维持了一个月;随后,上传到平流层的行星波减弱,同时平流层负位相的AO异常迅速传至地面,导致了有利于低温降雪的环流异常。 相似文献
9.
Extreme precipitation events identified using detrended fluctuation analysis (DFA) in Anhui,China 总被引：1，自引：1，他引：0
Qi Zhang Jiquan Zhang Denghua Yan Yongfang Wang 《Theoretical and Applied Climatology》2014,117(1-2):169-174
Extreme weather events include unusual, severe or unseasonal weather, and weather at the extremes of the historical distribution. They have become more frequent and intense under global warming, especially in mid-latitude areas. They bring about great agricultural and economic losses. It is important to define the threshold of extreme weather event because it is the starting point of extreme weather event research, though it has been of seldom concern. Taking extreme precipitation events in Anhui, China as an example, the detrended fluctuation analysis (DFA) method is introduced to define the threshold of extreme weather events. Based on it, the spatial and temporal distributions of extreme precipitation events are analyzed. Compared to the traditional percentile method, DFA is based on the long-term correlation of time series. Thresholds calculated by DFA are much higher than the 99th percentile and the values are higher in the south and lower in the north. This spatial pattern is similar to the annual precipitation spatial pattern. There is an obvious increasing trend in the number of days with extreme precipitation, especially after the 1980s. This observation supports the point that more extreme events happen under global warming. 相似文献
10.
Agricultural risk management policies under climate uncertainty 总被引：1，自引：0，他引：1
Jesús Antón Andrea Cattaneo Shingo Kimura Jussi Lankoski 《Global Environmental Change》2013,23(6):1726-1736
Climate change is forecasted to increase the variability of weather conditions and the frequency of extreme events. Due to potential adverse impacts on crop yields it will have implications for demand of agricultural risk management instruments and farmers’ adaptation strategies. Evidence on climate change impacts on crop yield variability and estimates of production risk from farm surveys in Australia, Canada and Spain, are used to analyse the policy choice between three different types of insurance (individual, area-yield and weather index) and ex post payments. The results are found to be subject to strong uncertainties and depend on the risk profile of different farmers and locations; the paper provides several insights on how to analyse these complexities. In general, area yield performs best more often across our countries and scenarios, in particular for the baseline and marginal climate change (without increases in extreme events). However, area yield can be very expensive if farmers have limited information on how climate change affects yields (misalignment in expectations), and particularly so under extreme climate change scenarios. In these more challenging cases, ex post payments perform well to increase low incomes when the risk is systemic like in Australia; Weather index performs well to reduce the welfare costs of risks when the correlation between yields and index is increased by the extreme events. The paper also analyses the robustness of different instruments in the face of limited knowledge of the probabilities of different climate change scenarios; highlighting that this added layer of uncertainty could be overcome to provide sound policy advice under uncertainties introduced by climate change. The role of providing information to farmers on impacts of climate change emerges as a crucial result of this paper as indicated by the significantly higher budgetary expenditures occurring across all instruments when farmers’ expectations are misaligned relative to actual impacts of climate change. 相似文献
11.
秋季北极海冰对中国冬季气温的影响 总被引：7，自引：0，他引：7
利用海冰资料、中国地面气候资料、环流特征量资料及NCEP/NCAR再分析资料,研究了秋季北极海冰变化对中国冬季平均气温、日气温变率以及异常低温天气的影响。分析结果表明,秋季北极海冰异常偏多年中国冬季常为暖冬;异常偏少年中国冬季常为冷冬,且异常低温天气出现频率更高,常发生低温灾害事件。秋季北极海冰通过影响后期的北半球极涡、东亚冬季风和西伯利亚高压进而影响中国冬季的平均气温,且通过影响冬季异常强西伯利亚高压的出现频次,影响中国冬季异常低温天气的发生频次。合成分析结果表明,秋季北极海冰异常偏少年的冬季,中国以北亚欧大陆高纬度的偏北风较强,且中国及其以北的中高纬度地区空气异常偏冷,导致极地和高纬度的冷空气易向南爆发,造成中国冬季气温偏低,异常低温天气频发。 相似文献
12.
2007年3月中国东部北方地区一次强灾害性暴风雪事件的成因初探 总被引：8，自引：0，他引：8
2007年3月3-5日,中国东部北方地区发生了近50年来历史同期最强的一次暴风雪事件,给该地造成了严莺的灾害和损失.通过分析这次暴风雪事件发生前期和同期的大尺度大气环流异常,探讨形成这次极端天气的可能物理机制.研究结果表明,在这次暴风雪事件发牛的前两周中,存在持续异常的北极涛动、南极涛动、欧亚型遥相关以及北太平洋涛动等大气模态.这些异常环流在中国东部沿岸地区引起了强劲的偏南风,由此给中国东部北方地区源源不断地输送暖湿空气,使得该地的水汽含量和气温不断升高,为这次暴风雪事件的发生准备厂良好的暖空气条件.当3月初大气环流发生调整,极地冷空气南下时,强劲的冷、暖空气交汇于中国东部北方地区,从而在该地形成了强大的冷锋系统,最终导致了这次强暴风雪事件的发生.研究结果表明,在预报与降水相关的天气时,必须考虑事发前期异常大气环流的信息,关注预报区域前期水汽的积累状况,这对于提高降水预报、特别是强降水预报的水平有着重要的意义. 相似文献
13.
On the relation between weather-related disaster impacts,vulnerability and climate change 总被引：1，自引：0，他引：1
Disasters such as floods, storms, heatwaves and droughts can have enormous implications for health, the environment and economic development. In this article, we address the question of how climate change might have influenced the impact of weather-related disasters. This relation is not straightforward, since disaster burden is not influenced by weather and climate events alone—other drivers are growth in population and wealth, and changes in vulnerability. We normalized disaster impacts, analyzed trends in the data and compared them with trends in extreme weather and climate events and vulnerability, following a 3 by 4 by 3 set-up, with three disaster burden categories, four regions and three extreme weather event categories. The trends in normalized disaster impacts show large differences between regions and weather event categories. Despite these variations, our overall conclusion is that the increasing exposure of people and economic assets is the major cause of increasing trends in disaster impacts. This holds for long-term trends in economic losses as well as the number of people affected. We also found similar, though more qualitative, results for the number of people killed; in all three cases, the role played by climate change cannot be excluded. Furthermore, we found that trends in historic vulnerability tend to be stable over time, despite adaptation measures taken by countries. Based on these findings, we derived disaster impact projections for the coming decades. We argue that projections beyond 2030 are too uncertain, not only due to unknown changes in vulnerability, but also due to increasing non-stationarities in normalization relations. 相似文献
14.
The literature suggests that extreme weather experiences have potential to increase climate change engagement by influencing the way people perceive the proximity and implications of climate change. Yet, limited attention has been directed at investigating how individual differences in the subjective interpretation of extreme weather events as indications of climate change moderate the link between extreme weather experiences and climate change attitudes. This article contends that subjective attribution of extreme weather events to climate change is a necessary condition for extreme weather experiences to be translated into climate change mitigation responses, and that subjective attribution of extreme weather to climate change is influenced by the psychological and social contexts in which individuals appraise their experiences with extreme weather. Using survey data gathered in the aftermath of severe flooding across the UK in winter 2013/2014, personal experience of this flooding event is shown to only directly predict perceived threat from climate change, and indirectly predict climate change mitigation responses, among individuals who subjectively attributed the floods to climate change. Additionally, subjective attribution of the floods to climate change is significantly predicted by pre-existing climate change belief, political affiliation and perceived normative cues. Attempts to harness extreme weather experiences as a route to engaging the public must be attentive to the heterogeneity of opinion on the attributability of extreme weather events to climate change. 相似文献
15.
2020年5月贵州省出现极端高温天气事件,本文利用贵州省84个气象观测站日平均气温和最高气温资料、美国气象环境预报中心的逐日再分析高度场资料以及美国海洋大气管理局的日平均海表面温度（SST）资料,利用超前滞后相关等方法对贵州省2020年5月“极端性高温事件”进行研究。得出如下结论：（1）2020年5月贵州省约有29%的站点极端日最高气温超过了1981年以来的历史极值,约58%的站点突破1981年以来5月同期历史极值,西太平洋副热带高压显示为异常西扩加强的态势,同时伴随南亚高压东伸增强,两个高压在不同高度上的配合导致深厚高压的异常出现,是此次贵州极端性高温事件发生的重要因素。（2） 2020年5月在欧亚大陆中高纬对流层上层有明显的Rossby波列结构,有利于贵州极端性高温事件出现。（3）热带西大西洋SST在月尺度内异常阶段性增暖,可作为贵州省极端性高温天气发生的重要前期信号,并且增暖过程比高温事件提前约14天,具有一定的前期指示意义。 相似文献
16.
前冬北半球环状模对春季中国东部北方地区极端低温的影响 总被引：5，自引：1，他引：4
对1959—2008年前冬(12—3月)北半球环状模与春季(3—5月)中国东部北方地区极端低温事件的关系进行诊断分析,发现前冬北半球环状模与春季中国东部北方地区极端低温事件存在显著负相关。当前冬北半球环状模偏强时,春季中国东部北方地区上空对流层高、低层分别出现位势高度的负、正异常,对应异常的下沉增温,东北冷涡偏弱,极端低温事件发生频次偏少,强度偏弱;反之,当前冬北半球环状模偏弱时,春季该地区极端低温事件发生的频次偏多,强度偏强。进一步研究表明,欧亚雪盖在前冬北半球环状模对春季中国东部北方地区极端低温的影响中起到潜在的桥梁作用,当前冬北半球环状模偏强(偏弱)时,同期欧亚大陆中高纬度地区偏暖(偏冷),欧亚雪盖面积较小(较大)。另外,欧亚雪盖面积异常具有较强的持续性,可以从前冬持续到春季。因此,当前冬欧亚雪盖面积较小时,春季欧亚雪盖面积也偏小,且对应春季东北冷涡强度偏弱,中国东部北方地区地表气温偏高,极端低温事件发生的频次偏少,强度偏弱;反之亦然。前冬北半球环状模与春季中国东部北方地区极端低温事件的负相关关系为预测中国东部北方地区春季极端低温事件的变化提供了一个潜在的前期信号。 相似文献
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Recent climate warming in the Arctic requires improvements in permafrost and carbon cycle monitoring, accomplished here by setting up long-term observation sites with high-quality in situ measurements of turbulent atmospheric energy fluxes applying the eddy covariance method and/or laser scintillometry in Arctic landscapes. Accurate quantification and well-adapted parameterizations of turbulent energy fluxes, e.g., during neutral to stable stratified conditions, are a fundamental problem in soil?Csnow?Cice?Cvegetation?Catmosphere interaction studies. We present results from the Arctic Turbulence Experiment (ARCTEX-2006) performed on the island of Svalbard, Norway, during the winter/spring transition 2006 that focus on data correction and quality assessment, on synoptic weather conditions, as well as site-specific micrometeorological features. A quality assessment and data correction adapted to the environmental conditions of polar regions demonstrates that specific measurement errors common at a high Arctic landscape could be minimized. We discuss the role of the intermittency of the turbulent atmospheric fluctuation of momentum and scalars, the existence of a disturbed vertical temperature profile (sharp inversion layer) close to the surface, and the relevance of possible free convection events for the snow or ice melt in the Arctic spring at Svalbard. Recommendations and improvements regarding the interpretation of eddy flux data as well as the arrangement of the instrumentation under polar distinct exchange conditions and (extreme) weather situations are presented. 相似文献
18.
Many earlier studies concluded that exposure to changes in local weather or extreme weather events prompt public interest in climate change, and in turn raise support for mitigation policies. However, these findings do not square with observations of record-breaking temperatures, and decades of failure to reduce greenhouse gas emissions. To address this conundrum, we use Protection Motivation Theory to form hypotheses on the specific type of climate change-related information that individuals seek during periods of extreme local weather. Using daily-level internet search engine data from Chinese cities, we find that residents are purposeful and rational in seeking information on climate change. Specifically, when faced with high or abnormal temperatures, they are much more likely to seek information to appraise their susceptibility to climate change threats, and evaluate coping responses. On the other hand, due to the lack of direct benefits, they do not seek out information on climate mitigation behaviors. In contrast to earlier studies, our findings suggest that it is unlikely that extreme weather events will prompt support for climate mitigation actions. Instead, as worldwide weather becomes more extreme and unpredictable, it is likely that public’s attention will shift in the direction of adaptation measures. 相似文献
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罗亚丽 《气候变化研究进展》2012,8(2):90-98
自1950年以来的观测证据表明,有些极端天气和气候事件已经发生了变化。全球尺度上,人为影响可能已经导致极端日最低和最高温度升高;由于平均海平面上升,人类活动可能已对沿海极端高水位事件的增加产生了影响;具有中等信度的是,人为影响已导致全球强降水增加;由于热带气旋历史记录的不确定性、缺乏对热带气旋与气候变化之间关联的物理机制的完整认识及热带气旋自然变率的程度,将可检测到的热带气旋活动变化归因于人为影响仅具有低信度。将单一的极端事件变化归因于人为气候变化具有挑战性。对极端事件变化预估的信度取决于事件的类型、区域和季节、观测资料的数量和质量、基本物理过程的认知水平及模式对其模拟的可靠性。 相似文献