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1.
东北气候和生态过渡区近50年来降水和温度概率分布特征变化 总被引：18，自引：11，他引：7
文章从中国160个站的观测资料中选取位于东北气候和生态过渡区内9个测站的冬、夏季降水和温度资料,分析该地区近50年来冬夏季降水和温度的年际变化及其概率分布特征,结果表明,东北气候和生态过渡区的冬夏季降水和温度有明显的年代际变化特征,在不同的年代际变化阶段,降水和温度的总体概率分布特征差异较大,这种概率分布形式的差异与高温、干旱等极端天气气候事件的频繁发生具有密切关系。20世纪80年代以来降水处于平均值减小的总体分布中,温度则处于平均值增加的总体分布中,因此该地区冬季发生暖冬和少雨(雪)的机会增大,夏季出现严重干旱和高温的可能性增大。 相似文献
2.
全球气候变化导致全球海洋酸化、冰雪融化、气温持续升高、极端天气发生频率增多,进而对社会经济系统产生深远影响。随着气候变化的加剧,抵抗气候风险能力较强的工业领域也遭受了严重的损失。目前,工业领域的脆弱性不断加深,工业经济损失的绝对量也在不断增长,定量评估工业经济损失是制定应对气候变化政策的重要依据,通过梳理当前的研究进展,可以为工业经济的评估提供思路和方法。因此,本文对工业领域受气候变化影响的正负面效应进行概述,发现不同工业部门受到气候变化的影响略有不同,部分区域的采矿业对气温升高的响应为正向,但风暴、干旱以及降雨会破坏采矿业的正常生产经营活动;制造业大多是室内作业,抵抗极端气候的能力相对较强,部分产业反应机制复杂;建筑业的损失多集中在间接损失,通过电力成本提高等反馈;电力、热力及水的生产和供应业在遭受极端气候时会出现传输供应损失,且作为碳排放最大的行业,其减排成本短期内会影响该部门的经济增长。工业部门为了应对气候变化付出了较大的适应和减缓成本,因此通过模型量化评估工业经济的损失,有利于制定合理的政策,保证工业经济平稳有序的增长。 相似文献
3.
This paper examines how extreme weather events affect the mobility of low-income urban residents in Ghana. Bringing together scholarship on extreme weather and mobilities, it explores the differential impact of flooding on their everyday lives as they navigate the cities of Accra and Tamale. A range of qualitative methods were drawn on, including semi-structured interviews, focus group discussions, and follow-along-participant observations in selected communities of both cities. Three key themes emerged: disrupted road and transport infrastructure, everyday mobility challenges, and coping/adaptive strategies. In flooding conditions, residents experienced difficulties leaving/returning home, engaging in income-generating activities, and accessing transport services and other key urban infrastructure. Conceptually, the paper reveals how disruption to urban residents’ daily movements and activities (re)produces new forms of mobilities and immobilities, which have three relational elements: postponed, improvised and assisted. Throughout the analysis, we show how these mobilities/immobilities vary by age and gender: all urban residents, (though women in particular), experience postponed mobility; young people especially engage in improvised mobility; and children and the elderly are in greatest need of assisted mobility. The paper thus contributes to scholarship on extreme weather events and mobility by providing a more spatially nuanced understanding of the multi-faceted domains in which flooding, socio-economic conditions and adaptive strategies intersect to influence urban mobility in resource poor settings. 相似文献
4.
THE 'LITTLE ICE AGE': RE-EVALUATION OF AN EVOLVING CONCEPT 总被引：4，自引：0，他引：4
JOHN A. MATTHEWS KEITH R. BRIFFA 《Geografiska Annaler: Series A, Physical Geography》2005,87(1):17-36
ABSTRACT. This review focuses on the development of the ‘Little Ice Age’ as a glaciological and climatic concept, and evaluates its current usefulness in the light of new data on the glacier and climatic variations of the last millennium and of the Holocene. ‘Little Ice Age’ glacierization occurred over about 650 years and can be defined most precisely in the European Alps (c. AD 1300–1950) when extended glaciers were larger than before or since. ‘Little Ice Age’ climate is defined as a shorter time interval of about 330 years (c. AD 1570–1900) when Northern Hemisphere summer temperatures (land areas north of 20°N) fell significantly below the AD 1961–1990 mean. This climatic definition overlaps the times when the Alpine glaciers attained their latest two highstands (AD 1650 and 1850). It is emphasized, however, that ‘Little Ice Age’ glacierization was highly dependent on winter precipitation and that ‘Little Ice Age’ climate was not simply a matter of summer temperatures. Both the glacier‐centred and the climate‐centred concepts necessarily encompass considerable spatial and temporal variability, which are investigated using maps of mean summer temperature variations over the Northern Hemisphere at 30‐year intervals from AD 1571 to 1900. ‘Little Ice Age’‐type events occurred earlier in the Holocene as exemplified by at least seven glacier expansion episodes that have been identified in southern Norway. Such events provide a broader context and renewed relevance for the ‘Little Ice Age’, which may be viewed as a ‘modern analogue’ for the earlier events; and the likelihood that similar events will occur in the future has implications for climatic change in the twenty‐first century. It is concluded that the concept of a ‘Little Ice Age’ will remain useful only by (1) continuing to incorporate the temporal and spatial complexities of glacier and climatic variations as they become better known, and (2) by reflecting improved understanding of the Earth‐atmosphere‐ocean system and its forcing factors through the interaction of palaeoclimatic reconstruction with climate modelling. 相似文献
5.
过去50年内蒙古极端气候事件时空格局特征 总被引：4，自引：1，他引：3
为了掌握内蒙古极端气候事件的发生趋势与时空格局,本文运用内蒙古自治区境内46个国家级气象站点的日值记录数据,计算与植被生长的水热条件及寒旱灾害直接相关的极端气候事件指数,分析过去50年内蒙古温度和降水气候事件的时空演变特征。研究结果表明,研究区极端温度事件的发生频率与持续时间迅速变化发生于20世纪90年代以来,60年代至80年代末呈平稳态势。表征低温事件的霜日日数（FD0）、冷昼日数（TX10p）、冷夜日数（TN10p）、冷持续指数（CSDI）等指数均呈现下降趋势,同时表征高温事件的夏日指数（SU25）、作物生长期（GSL）、暖昼日数（TX90p）、暖夜日数（TN90p）、热持续指数（WSDI）则均呈上升趋势。与极端高温事件发生频率的加剧在90年代初开始凸显不同,表征强降水事件发生频率和强度的极端降水指标的显著变化发生在近10年。研究区极端温度指数过去50年的变化过程几乎没有明显的空间分异特征,但是在位于农牧交错区的部分站点的强降水事件呈现出与大多数站点不同的特征,最近10年的强降水事件高于前一时段,而其他多数站点最近10年的极端降水指数均低于前一时段。 相似文献
6.
为了掌握内蒙古极端气候事件的发生趋势与时空格局,本文运用内蒙古自治区境内46个国家级气象站点的日值记录数据,计算与植被生长的水热条件及寒旱灾害直接相关的极端气候事件指数,分析过去50年内蒙古温度和降水气候事件的时空演变特征。研究结果表明,研究区极端温度事件的发生频率与持续时间迅速变化发生于20世纪90年代以来,60年代至80年代末呈平稳态势。表征低温事件的霜日日数（FD0）、冷昼日数（TX10p）、冷夜日数（TN10p）、冷持续指数（CSDI）等指数均呈现下降趋势,同时表征高温事件的夏日指数（SU25）、作物生长期（GSL）、暖昼日数（TX90p）、暖夜日数（TN90p）、热持续指数（WSDI）则均呈上升趋势。与极端高温事件发生频率的加剧在90年代初开始凸显不同,表征强降水事件发生频率和强度的极端降水指标的显著变化发生在近10年。研究区极端温度指数过去50年的变化过程几乎没有明显的空间分异特征,但是在位于农牧交错区的部分站点的强降水事件呈现出与大多数站点不同的特征,最近10年的强降水事件高于前一时段,而其他多数站点最近10年的极端降水指数均低于前一时段。 相似文献
7.
Leif Kullman 《Geografiska Annaler: Series A, Physical Geography》1997,79(3):139-165
The paper reviews various kinds of geoecological change in the tree-limit ecotone of the Scandes Mountains during the period 1970–95. The focus of the study is a part of a regional network of sites intended for long-term tree-limit monitoring, with special stress on effects of climatic variability. The elevational tree-limits of Betula pubescens sp. Sortuosa, Picea abies and Pinus sylvestris, which rose in response to the climatic amelioration earlier this century, now show clear symptoms of increasing climatic stress and disturbance. This manifests as defoliation, growth recession and reproductive failure, locally leading to some initial elevational tree-limit retraction (unbalanced mortality). Defoliation was preceded by decades of weak summer cooling and an increasingly maritime climate, but recently it correlates significantly with low winter soil temperatures, causing death of needles, shoots and buds. In some habitats, Betula pubescens has suffered from mechanical stress and disturbance by increased snow accumulation. Tree-limit decline is paralleled by analogous responses of high-elevation boreal forests as well as the ground cover, encompassing elevational range-limit retraction of certain plant species, deterioration of alpine/subalpine dwarf-shrub heaths and terricolous lichen mats. These processes coincide with indications of enhanced periglacial activity, chiefly wind deflation of frost-heaved top-soils at exposed sites. Presumably, reindeer trampling and grazing play a certain role in the latter context, although this disturbance interacts with climate cooling and increased storminess. Short-term extreme events, particularly concerning winter climate (e.g. ground frost), represent previously underrated disturbance mechanisms in cold-stressed, high-altitude boreal forest. The results suggest mechanisms of tree-layer regression, which lag behind the most severe stresses and disturbances by decades and make cold-marginal trees increasingly sensitive to climatic extremes and, in addition, unable to respond progressively to later positive weather anomalies, due to major defoliation and hypothetical xylem cavitation. The recorded changes are logical in consequence of the irregular climatic cooling and a more maritime climate since the late 1930s. In a wider perspective, the results fit a current pattern of natural geoecological destabilization and rapid vegetation change in the North Atlantic region. In addition, the results are discussed in the perspective of global climate change and biogeographical records over the past few decades. 相似文献
8.
Climatic change: Causal correlations over the last 240 Ma 总被引：1，自引：1，他引：0
Stuart A. Harris 《寒旱区科学》2013,5(3):0259-0274
The climate of the Earth has been oscillating between mega warm periods and mega cold periods for 3,000 Ma. Each mega cold period included alternating major warm and cold events. The present mega cold period commenced about 44 Ma in the polar regions as the seas cooled following the loss of the circum-equatorial ocean. Before then, a mega warm period lasted for more than 200 Ma. The frequency of the major cold events within the present mega cold period is increasing, with each continent being under the influence of a different set of climatic controls. There are many causes of these shifts in climate, ranging from fluctuating meridional ocean currents, rearrangement of tectonic plates, and changes in ocean gateways. These are enhanced by a combination of Milankovitch cycles and many other medium to small oscillations and cyclic controls that cause the daily, monthly, and seasonal fluctuations in weather. Examples are given of how these can cause a change from cold to warm events, or vice versa, at present-day or mega scales, aided by eustatic changes in sea levels and changes in the distribution of air masses, sea ice, and snow. 相似文献
9.
根据1960-2015年河西走廊东部5个气象站逐日最低、平均气温资料,通过固定阈值和百分位阈值法定义了低温事件,采用气候统计学方法,分析了该区域低温事件的强度、极值和日数的变化特征,统计结果显示,受海拔高度、地形地势和植被覆盖的影响,河西走廊东部低温事件的空间分布均存在明显地域差异,均为高寒山区天祝强度和极值最强,日数最多,绿洲平原区凉州强度和极值最弱,日数最少。河西走廊东部年代和年低温事件强度和极值呈减弱趋势,日数呈减少趋势,2010-2015年减弱和减少的趋势尤为明显。年低温事件强度、极值和日数的时间序列均存在着周期性变化,但都没有发生气候突变,只出现了转折年份。两种标准的低温事件均出现在1~3月和11~12月,强度、极值和日数高峰值均在1月或12月。年低温事件存在一定的异常性,正常低温事件强度、极值和日数的年份概率在64.3%～80.4%,对安全生产造成危害的低温事件强度、极值偏强和特强年份的概率在7.1%～16.1%,日数偏多和特多年份的概率共为16.1%。本研究可为低温的预报预警提供技术支持,同时可为地方政府提供准确的决策依据,对区域气候变化研究和经济发展有重要意义。 相似文献
10.
通过对以《有泰拉萨天气日志》为主的历史文献资料的深入挖掘 ,作者分析了 1 90 4年 2月 9日～ 1 90 7年 4月 1 7日拉萨的气候特征 :气候温暖 ,暖冬现象显著 ,而且 1 90 5年气温高于 1 90 4年 ;干旱气候占主导地位 ,间有多雨期 ;天气多变 ,多风 ,有雾 ;水灾、雪灾、干旱等自然灾害严重。拉萨与全球同时段的气候变化大体一致。 相似文献
11.
Gregory E. Faiers Barry D. Keim Katherine K. Hirschboeck 《The Professional geographer》1994,46(2):156-163
This research classifies extreme three-hour and 24-hour rainfall events in Louisiana by synoptic weather types (Frontal, Gulf Tropical Disturbance, and Air Mass). These classes were used to analyze differences in frequencies and intensities of extreme rainfall. Significant differences were found in the storm frequencies by weather type. However, no significant differences were detected in rainfall intensities between weather types during either duration. These findings have a bearing on statistical procedures associated with estimating storm probabilities in the region. 相似文献
12.
13.
《The Journal of geography》2012,111(7):49-53
Abstract The potentially severe strain that subnormal winter temperatures would impose upon reduced heating fuel supplies prompted publication of a long-range, national, winter weather forecast in November 1973. However, limitation of the art of weather forecasting that stem ultimately from the complex episodic nature of weather behavior diminish the reliability of this outlook. In spite of the complexity encountered along the way, a journey into weather records of the past does reveal some observations about weather activity that are useful in assessing winter temperature prospects. These observations include the characteristic nonuniformity of weather behavior, the existence of long-range and seasonal climatic trends, and the thermal effects of early-season establishment of a heavy snow cover. 相似文献
14.
Modelling Transient Ground Surface Temperatures of Past Rockfall Events: Towards a Better Understanding of Failure Mechanisms in Changing Periglacial Environments 
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下载免费PDF全文 Rachel Luethi Stephan Gruber Ludovic Ravanel 《Geografiska Annaler: Series A, Physical Geography》2015,97(4):753-767
Despite the rising interest in mountain permafrost due to climatic changes and a noticed increase of registered rockfall events in the European Alps and other mountain ranges, little is known about transient thermal conditions in the detachment areas of rockfalls. Temperature conditions prior to the rockfall events of 144 past events in the European Alps were modelled with a physically based ground temperature model. To minimise the impact that uncertainty has on interpretations, only relative values were used, that is, percentiles obtained from cumulative distribution functions of the modelled ground surface temperatures from the beginning of the meteorological measurement series up to the event dates. Our results suggest that small and mid‐sized rockfalls (volumes up to 100 000 m3) from high elevation occurred mainly during short‐term periods of unusually high temperatures. This was neither found to be a result of the seasonal distribution (most analysed events in higher elevations occurred from July to September) nor of the longer‐term temporal distribution (most analysed events occurred after 2000) only. Plausible explanations are either a destabilisation related to advective thaw or failure due to stress redistribution caused by large temperature variations. Large deep‐seated rock slope failures (≥100 000 m3) in high elevation occurred all year round. 相似文献
15.
Late Holocene lake-level and lake development signals in Lower Herring Lake, Michigan 总被引：2，自引：0，他引：2
Julie A. Wolin 《Journal of Paleolimnology》1996,15(1):19-45
Paleolimnological investigations of a marginal lake in the Lake Michigan basin revealed signals of long-term lake-level changes primarily controlled by climatic forces. Multiple analyses identified concurrent signals in sediment chemistry, grain size, and the microfossil record. Coarse-grained sediments, benthic diatoms, and nutrient response species increased as lake levels rose or fell. Finer sediments and higher percentages of taxa associated with stable thermocline conditions occurred during high-lake periods. Sedimentary evidence revealed corresponding strong high-lake signals c. 2500–2200, 1800–1500, 1170–730, and 500–280 BP. Low-lake periods occurred c. 1500–1170 and 700–500 B.P. An additional signal of lake-level decline was apparent beginning c. 280 BP but was interrupted by anthropogenic effects. Evidence of extreme low-lake levels (c. 1400–1300 BP), and signals for a medieval warming period (1030–910 BP) and the Maunder minimum (370–325 BP) indicate occurrence of short-lived dry climatic conditions. 相似文献
16.
William Wyckoff 《The Professional geographer》2013,65(1):122-124
Loblolly pines in Texas and Louisiana exhibit different reactions to moisture extremes, as indicated by the susceptibility of weakened individuals to attack by southern pine beetles. In Texas, intense insect outbreaks among pines occur during periods of extreme moisture surplus, whereas extreme moisture deficits render the Louisiana pines susceptible to attack. Intraspecies tree reponse to moisture extremes therefore appears to be spatially variable and partially dependent upon the frequency occurrence of severe climatic conditions. 相似文献
17.
通过对西北东部地区1470-1912年干旱灾害历史资料的搜集整理,根据干旱发生强度、持续时间、发生范围,定义了强旱事件,建立了极旱因子模型,复原了443年西北东部地区极端干旱事件,并根据时间分形原理,挖掘出极旱事件时间序列的分维特征。经过对比分析得到以下结论：建立的模型结果与记载结果具有显著的相似性;全序列旱灾时间分维值随极旱强度的增加而降低,与极旱发生周期呈反位相关系;各类别极旱有自己的时间重演律,极旱程度越轻,无标度区越宽,分维值越高,短周期比较明显。 相似文献
18.
S. Begzsuren J. E. Ellis D. S. Ojima M. B. Coughenour T. Chuluun 《Journal of Arid Environments》2004,59(4):50
We investigated how both droughts and dzuds (severe winter weather) control livestock mortality in a non-equilibrium steppe ecosystem of Mongolia, Gobi Three Beauty National Park. These steppe ecosystems have developed under high interannual variability of rainfall and nomadic grazing systems. Interannual precipitation variation was 39%, with 128 mm mean annual precipitation. The effect of climate variability and extreme events on livestock mortality is a critical aspect for the Mongolian economy. Analysis of drought and precipitation variability on livestock mortality rate was not significantly influenced by the index of mean annual precipitation and annual winter temperature. Overall, unlike hot dry regions, pastoral livestock mortality in the cold dry regions was affected more by dzuds and annual growing seasonal rain than by droughts. Dzuds can be frequent events, occurring as often as once every 2 and 3 years within a decade. The average annual livestock mortality for the combined drought and dzuds years (18%) was 4.8% greater than the years with dzuds alone, and 7% greater than in years with only drought. Thus livestock mortality appears to be more sensitive to dzuds than to droughts, and that dzuds contributes more to livestock mortality even years where combined drought and winter storms occur. 相似文献
19.
Lake sediments contain viable allochthonous bacteria that can be cultured and used for palaeoecological studies. To be a good palaeoindicator, a bacterium must be able to survive in sediments for long periods of time, but also be unable to reproduce in the lake bottom. Bacteria can survive the unfavourable environmental conditions in lake sediments as resting cells. The endospore is the most specialized form and gives the bacterium an extreme longevity. The oldest viable endospores isolated from lake sediments that we are aware of are about 9000 years old.Several species, mainly in the genera Thermoactinomyces, Bacillus and Clostridium, form endospores. Clostridium perfringens has been used as palaeoindicator for sewage pollution, while Thermoactinomyces vulgaris is an indicator for past agricultural activity in the boreal forest zone and a potential climatic indicator in other vegetation zones. Although isolation and enumeration of bacterial endospores from lake sediments is rather easy and has considerable potential as a powerful tool in palaeoecology, the number of studies using palaeoecological approaches is limited. 相似文献
20.
内蒙古大兴安岭林区极端气温事件变化特征 总被引：2，自引：1，他引：1
利用内蒙古大兴安岭林区11个气象站1971~2014年日平均气温数据,采用线性趋势、Morlet小波分析、克里金插值法对内蒙古大兴安岭林区极端气温的年变化进行分析。研究表明：极端高温天气和生物生长季天数在20世纪80年代中期以后呈显著增多趋势,极端低温天气呈显著减少趋势;在空间分布上,所有站点极端高温天气和生物生长季天数呈上升趋势,极端低温天气呈下降趋势,但空间差异明显。极端低温天气主要受27、18、11、7 a时间尺度周期影响。极端高温天气28 a左右周期振荡最为强烈,视为第一主周期,对极端高温天气影响最为显著,在2018年以后的大约8 a间（2019~2026年）极端高温天气可能会更加频繁。生物生长季受28 a时间尺度周期影响,且在2015~2022年生物生长季天数增长处于偏大期。 相似文献