共查询到20条相似文献，搜索用时 125 毫秒
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华北北部黑风暴的气候学特征 总被引：14，自引：0，他引：14
使用内蒙古中西部７２个地面测站１９５７～１９９６年历史资料,分析研究了该地区黑风暴的气候学特征,包括黑风暴的地理分布、年代际变化、年际变化、年变化、旬变化、日变化等时间变化特征和强度变化;讨论了形成上述变化特征的气候成因。得到如下结论：内蒙古中西部是黑风暴的易发区和多发区,最大中心位于内蒙古中部的朱日和;黑风暴的时间变化特征显著;强度有较大差异。 相似文献
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陆地生态系统与全球变化相互作用的研究进展 总被引：36，自引：3，他引：36
全球变化及其对生态系统特别是陆地生态系统的影响已经严重地影响到人类生存环境与社会经济的可持续发展 ,引起了各国政府、科学家及公众的高度关注。文中从CO2 浓度倍增、温度变化、水分变化、水热与CO2 协同作用、辐射变化、臭氧变化以及人为干扰等气候环境变化对植物光合生理、生长发育、物质分配、水分利用、碳氮代谢等的影响方面阐述了全球变化影响生态系统的过程与机理 ;从地理分布范围、物候、结构与功能、生态系统的稳定性等方面分析了中国植被、森林生态系统、草原生态系统与农田生态系统对全球变化的响应 ;从植被变化引起的动力条件与热力条件的变化及植被固碳潜力的变化探讨了植被对于气候的反馈作用。在此基础上 ,基于当前全球变化研究前沿 ,提出了未来关于陆地生态系统与全球变化相互作用研究需要重视的方面 ,尤其是关于生态系统对全球变化响应的阈值研究应引起高度重视。 相似文献
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1960—2009年中国年降水量的年际及年代际变化特征 总被引：1，自引：0，他引：1
利用1960-2009年中国台站降水量资料,揭示了全国、区域年降水量变化的多时间尺度的复杂结构和地区性差异,并根据年代际周期对未来降水量变化的贡献进行了预估。我国北方年降水量年际变化较强,年际变化对年降水量的贡献较大;南方年降水量年际变化相对较弱,年际变化对降水量的贡献较小,东北和西北地区年降水量的年代际变化较强,年代际变化明显,且同位相;其他地区年降水量年代际变化相对较弱。我国东北、西北、华南、青藏高原、西南地区年降水量的年代际变率对年降水量的贡献目前处于下降阶段,未来5-10年年代际变化的贡献可能继续呈下降趋势;长江中下游地区年降水量的年代际变率对年降水量的贡献目前处于上升阶段,未来5-10年年代际变化的贡献可能继续呈上升趋势。 相似文献
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吉林省近50年气温概率分布变化特征 总被引：1，自引：0，他引：1
本文选取了吉林省10个测站的冬、夏季气温资料,采用气候统计学分析方法,探讨了吉林省冬、夏季气温的年际、年代际变化及其概率分布变化特征。结果表明,20世纪70年代末以来,吉林省的夏、冬季气温表现为两种变化特征,一是均值的显著变化;二是方差的显著变化。吉林省夏季和冬季气温均有明显的年代际变化。在不同的年代际变化阶段,气温的总体概率分布特征差异很大,这种概率分布形式的差异与高温、低温等极端天气气候事件发生的频繁与否具有密切关系。同时,冬、夏季气温变化特征还表现为平均值的增加,因此吉林省发生暖冬及夏季高温的机率增大。 相似文献
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美国全球变化研究现状 总被引：17，自引：2，他引：15
美国的全球变化研究主要由美国全球变化研究计划（ＵＳＧＣＲＰ）支持,重点资助季节—年际尺度气候变率,十年—百年尺度的气候变化,臭氧、ＵＶ辐射以及大气化学的变化,土地利用以及陆地、海洋生态系统的变化等４个领域。当前,水汽与云仍是全球变化研究中不确定性较大的一个方面,因而受到关注。关于气候变化的信号检测以及成因分析也是一个研究热点。气候模拟研究是全球变化研究的一个主要方法。卫星资料在全球变化研究中的应用取得了大量成果。近期美国在全球变化研究领域的重点是气候模拟,短期气候预测,十年—百年尺度的气候变化,臭氧、ＵＶ辐射以及大气化学的变化,地表以及陆地、海洋生态系统变化,对全球变化的区域尺度估计,卫星资料的应用,气候变化影响的国家级评估等８个方面。 相似文献
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《中国气象科学研究院年报》2009,(1):9-14
2009年度气候系统研究所在季风变化机理、青藏高原热状况变化对气候的影响、海洋变化过程和机理、海-陆-气相互作用对东亚季风的影响,以及极地气候变化对东亚季风影响等几个方面取得可喜进展。 相似文献
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西藏羊八井辐射观测初步分析 总被引：1，自引：0，他引：1
利用西藏羊八井2009年5月至2010年4月的辐射观测数据,统计了总辐射、紫外辐射、长波辐射、净辐射的日变化、月变化和季节变化,并分析了地表辐射超过太阳常数的发生频率及原因。结果表明,羊八井地区总辐射、紫外辐射、长波辐射、净辐射均表现出明显的日变化、月变化和季节变化特征;总辐射与地表短波反射辐射、总辐射与紫外辐射均表现出明显的正相关关系;大气逆辐射和地表长波辐射之间呈现出一定的的正相关关系。 相似文献
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本文综合国内外有关资料, 从全球气候系统辐射能量平衡原理出发, 概述了影响全球气候长期变化的几个主要外部强迫因素：大气上界辐射变化（ 地球轨道形状变化和太阳活动） 、温室气体变化、气溶胶和火山活动、下垫面物理景观变化。分别论述了他们对气候变化的影响机制、辐射效应及作用效果。这些因素多与人类活动有关。 相似文献
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Antti Kilpeläinen Hilppa Gregow Harri Strandman Seppo Kellomäki Ari Venäläinen Heli Peltola 《Climatic change》2010,99(1-2):193-209
This work studied the temporal and spatial variability of the risk of snow-induced forest damage in Finland under current and changing climatic conditions until the end of this century. The study was based on a snow accumulation model in which cumulative precipitation, air temperature and wind speed were used as input variables. The risk was analyzed in terms of the number of days per year when the accumulated amount of snow exceeded 20 kg m???2. Based on the risk, the forest area and mean carbon stock of seedling, young thinning and advanced thinning stands at risk were calculated. Furthermore, the number of 5-day periods, when the accumulated amount of snow exceeded a risk limit, was calculated for the current and changing climatic conditions in order to study the frequency of damaging snowfalls. Compared to the baseline period 1961–1990, the risk of snow-induced forest damage and the amount of damaging snowfalls were predicted to decrease from the first 30-year period (1991–2020) onwards. Over the whole country, the mean annual number of risk days decreased by 11%, 23% and 56% in the first, second and third 30-year period, respectively, compared to the baseline period. In the most hazardous areas in north-western and north-eastern Finland, the number of risk days decreased from the baseline period of over 30 days to about 8 days per year at the end of the century. Correspondingly, the shares of the forest area at risk were 1.9%, 2.0% and 1.0% in the first, second and third 30-year period, respectively. The highest mean annual carbon stocks of young stands at risk were found in central, north-eastern and north-western Finland in the first and second 30-year period, varying between 0.6 and 1.2 Mg C ha???1 year???1, meaning at highest 3% of the mean carbon stock (Mg C stem wood ha???1) of those areas. This study showed that although the risk of snow-induced forest damage was mainly affected by changes in critical weather events, the development of growing stock under the changing climatic conditions also had an effect on the risk assessment. However, timely management of forest stands in the areas with a high risk of snow-induced damage contributes to the trees’ increased resistance to the damage. 相似文献
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气候变化对黑河流域生态环境的影响 总被引：9，自引：5，他引：9
本文介绍了黑河流域的气候概况，分析了近40a流域内以气温和降水为主的气候要素变化，得出黑河流域发生了以“增暖”为主要特征的气候变化。流域生态环境受气候变暖的影响明显。在灾害性天气强度、森林面积、土地荒漠化、湖泊萎缩、草原退化等方面日趋恶化。并就如何保护黑河流域生态环境提出了建议。 相似文献
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The durability of concrete is determined largely by its deterioration over time which is affected by the environment. Climate change may alter this environment, causing an acceleration of deterioration processes that will affect the safety and serviceability of concrete infrastructure in Australia, U.S., Europe, China and elsewhere. This investigation of concrete deterioration under changing climate in Australia uses Monte-Carlo simulation of results from General Circulation Models (GCMs) and considers high greenhouse gas emission scenarios representing the A1FI schemes of the IPCC. We present the implications of climate change for the durability of concrete structures, in terms of changes in probability of reinforcement corrosion initiation and corrosion induced damage at a given calendar year between 2000 and 2100 across Australia. Since the main driver to increased concrete deterioration is CO2 concentration and temperature, then increases in damage risks observed in Australia are likely to be observed in other concrete infrastructure internationally. The impact of climate change on the deterioration cannot be ignored, but can be addressed by new approaches in design. Existing concrete structures, for which design has not considered the effects of changing climate may deteriorate more rapidly than originally planned. 相似文献
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长江中下游油菜春季湿渍害灾损风险评估研究 总被引：2，自引：0，他引：2
在前期工作基础上,借鉴冬小麦湿渍害判别指数的构建方法,选取降雨量、日照和作物需水量作为油菜湿渍害气象判别指数的构建因子,结合油菜春季湿渍害的产量实际损失,分别从受灾频率、历年受灾站数等角度分析了油菜湿渍害发生的时空分布特征,通过对各气候区平均湿渍害灾年、因灾减产年及各等级减产年的统计,并对比成灾频率和受灾频率,对研究区油菜春季湿渍害进行成灾分析;依据不同等级的减产强度及其发生概率得到油菜湿渍害产量损失风险强度,基于减产频率和产量灾损风险强度最终建立风险评估模型,并依据风险值大小进行分区,同时,为更好地掌握油菜湿渍害在1961—2010年变化情况,分别计算了各地1961—1990、1971—2000及1981—2010年三个时段的风险评估值,以探寻各时段风险区的变化。结果表明:随着时间的推移,研究区内风险高值区范围不断缩小;综合50年的情况看,风险高值区主要位于安徽的江淮西部及江南大部、鄂东南及苏南的局部地区,占全区台站37%;风险中值区的覆盖范围最大,约55%,主要包括安徽东部、江苏的淮北西部、江淮之间、苏南西部及东北部、湖北大部(除了鄂东南、鄂西南的西南角);风险低值区范围最小,约8%,主要分布在鄂北局部和江苏淮北东部地区。 相似文献
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An artificial cloud seeding experiment was performed over the Japan Sea in winter to show how massive seeding could be effective to mitigate heavy snowfall damage. The results showed that 20 min after cloud seeding, a portion of the radar echo beneath the seeding track was weakened to divide the radar echo into two parts. In order to analyze the results, a numerical simulation was conducted by using the Weather Research and Forecasting model verion 3.5.1. In this simulation, the seeding effects were represented as phenomena capable of changing rain particles by accreting cloud ice and snow to form graupel particles and by changing cloud liquid water to snow particles. The graupel particles fell rapidly, thus temporarily intensifying the rainfall, which subsequently decreased. Therefore, the weakened radar echo in the field experiment is deemed to have been caused by the increase in rapidly falling graupel particles. 相似文献
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利用地面观测和探空资料及NCEP 1°×1°再分析资料,分析了2009年11月25—27日江苏南部大雾的成因。结果表明：逆温层的高度及强度与雾的浓度关系密切,弱冷暖平流有利于产生雾,但是温度平流在近地面一定高度迅速逆转使得温度层结由不稳定转为稳定更利于浓雾产生。边界层在低层辐合上升与高层辐散下沉的界面中形成逆温层,是产生浓雾的重要因素。对大雾天气进行诊断分析,有利于更加准确地对大雾天气进行数值预报,减轻此类灾害性天气的危害。 相似文献
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Fluvial flood risk in Europe in present and future climates 总被引：2，自引：0，他引：2
Luc Feyen Rutger Dankers Katalin Bódis Peter Salamon José I. Barredo 《Climatic change》2012,112(1):47-62
In this work we evaluate the implications of climate change for future fluvial flood risk in Europe, considering climate developments
under the SRES A2 (high emission) and B2 (low emission) scenario. We define flood risk as the product of flood probability
(or hazard), exposure of capital and population, and vulnerability to the effect of flooding. From the European flood hazard
simulations of Dankers and Feyen (J Geophys Res 114:D16108. doi:, 2009) discharges with return periods of 2, 5, 10, 20, 50, 100, 250 and 500 years were extracted and converted into flood inundation
extents and depths using a planar approximation approach. Flood inundation extents and depths were transformed into direct
monetary damage using country specific flood depth-damage functions and land use information. Population exposure was assessed
by overlaying the flood inundation information with data on population density. By linearly interpolating damages and population
exposed between the different return periods, we constructed damage and population exposure probability functions under present
and future climate. From the latter expected annual damages (EAD) and expected annual population exposed (EAP) were calculated.
To account for flood protection the damage and population exposure probability functions were truncated at design return periods
based on the country GDP/capita. Results indicate that flood damages are projected to rise across much of Western Europe.
Decreases in flood damage are consistently projected for north-eastern parts of Europe. For EU27 as a whole, current EAD of
approximately €6.4 billion is projected to amount to €14–21.5 billion (in constant prices of 2006) by the end of this century,
depending on the scenario. The number of people affected by flooding is projected to rise by approximately 250,000 to 400,000.
Notwithstanding these numbers are subject to uncertainty, they provide an indication of potential future developments in flood
risk in a changing climate. 相似文献
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黄河源区是三江源自然保护区的重要组成部分,在全球气候变暖和日趋频繁的人类活动的共同影响下,黄河源区的生态结构受到严重干扰。通过对黄河源区域生态与自然环境演变特征研究进展的概括总结,从生态系统和物理环境2个方面归纳了黄河源区主要的生态环境问题：（1）植被、冻土和湿地生态系统不断退化;（2）气候暖干化、径流变化、土壤侵蚀、土壤沙漠化、土壤碳流失、鼠害和人为影响加剧。根据面临的生态环境问题提出了区域生态与自然环境保护的相应对策和建议：形成完善的生态补偿机制;加强生态环境保护立法;建立统一的监督管理机构;建立有效的执法队伍;划分功能区;发展生态旅游;强化全社会的环保意识。 相似文献
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Fires and their associated carbon and air pollutant emissions have a broad range of environmental and societal impacts, including negative effects on human health, damage to terrestrial ecosystems, and indirect effects that promote climate change. Previous studies investigated future carbon emissions from the perspective of response to climate change and population growth, but the compound effects of other factors like economic development and land use change are not yet well known. We explored fire carbon emissions throughout the 21st century by changing five factors (meteorology, biomass, land use, population density, and gross domestic product [GDP] per capita). Compared to the historical period (2006–2015), global future fire carbon emissions decreased, mainly caused by an increase in GDP per capita, which leads to improvement in fire management and capitalized agriculture. We found that the meteorological factor has a strong individual effect under higher warming cases. Fires in boreal forests were particularly expected to increase because of an increase in fuel dryness. Our research should help climate change researchers consider fire-carbon interactions. Incorporating future spatial changes under diverse scenarios will be helpful to develop national mitigation and adaptation plans. 相似文献