共查询到20条相似文献，搜索用时 718 毫秒
1.
Markus Reuter Andrea K. Kern Mathias Harzhauser Andreas Kroh Werner E. Piller 《Gondwana Research》2013,23(3):1172-1177
Precipitation over India is driven by the Indian monsoon. Although changes in this atmospheric circulation are caused by the differential seasonal diabatic heating of Asia and the Indo-Pacific Ocean, it is so far unknown how global warming influences the monsoon rainfalls regionally. Herein, we present a Miocene pollen flora as the first direct proxy for monsoon over southern India during the Middle Miocene Climate Optimum. To identify climatic key parameters, such as mean annual temperature, warmest month temperature, coldest month temperature, mean annual precipitation, mean precipitation during the driest month, mean precipitation during the wettest month and mean precipitation during the warmest month the Coexistence Approach is applied. Irrespective of a ~ 3–4 °C higher global temperature during the Middle Miocene Climate Optimum, the results indicate a modern-like monsoonal precipitation pattern contrasting marine proxies which point to a strong decline of Indian monsoon in the Himalaya at this time. Therefore, the strength of monsoon rainfall in tropical India appears neither to be related to global warming nor to be linked with the atmospheric conditions over the Tibetan Plateau. For the future it implies that increased global warming does not necessarily entail changes in the South Indian monsoon rainfall. 相似文献
2.
The global mean temperature during the recent decade (2007-2016) has increased above 1 ℃ relative to the pre-industrial period (1861-1890). The climate change and impact under 1.5 ℃ warming in the future have become a great concern in global society. Temperature projections, especially in regional scale, show great uncertainty depending on used climate models. Taking advantage of pattern scaling technique and observed temperature changes during 1951-2005, we tried to project the temperature changes globally under 1.5 ℃ threshold relative to current climate state, i.e. about 1 ℃ warming around 2007-2016. The projections of 21 climate models from the Coupled Model Intercomparison Project - Phase 5 under four Representative Concentration Pathways (RCP2.6, RC4.5, RCP6.0 and RCP8.5) were used to correct the assumptions in pattern scaling. Results showed that the geographical distribution and warming amplitude of surface air temperature changes under 1.5 ℃ threshold are similar in the four scenarios. Warming over most of the land would be above 0.6 ℃, 0.3 ℃ warmer than ocean. The Northern Hemisphere would be 0.2 ℃ warmer than the Southern Hemisphere. The temperature over China region will increase by 0.7 ℃. The warming in the Northern and Central China under RCP2.6 was obviously higher than that in the other scenarios. Ignoring the impact of correction method, uncertainty in temperature projection based on pattern scaling was much smaller than that in climate models, both in global and regional scales. 相似文献
3.
《Quaternary Science Reviews》2005,24(14-15):1547-1557
Correlation of paleoclimatic evidence with orbital changes shows that the build-up of polar ice accelerated when low obliquity coincided with perihelion in Northern Hemisphere winter. Under low obliquity the insolation was channeled to the tropics at the expense of both polar caps. As perihelion moved from winter solstice toward spring equinox, the solar beam in astronomic winter and spring became stronger than in summer and autumn. This orbital configuration under climate conditions like today would lead to warming of tropical oceans but cooling of the polar regions. The areally weighted global mean surface temperature, which is dominated by the low latitudes, would increase. Consequently, during the first millennia, the early glacial ice build-up was most likely accompanied by global warming. It was the associated increase of meridional insolation and temperature gradients, which were instrumental in the transition to a glacial.A significant part of the current global warming is due to the gradual temperature increase of the tropical oceans. As the changing orbital configuration today resembles that of the last interglacial/glacial transition, the warming is likely to have a natural component. 相似文献
4.
Rainfall Variability and Changes in Southern Africa during the 20th Century in the Global Warming Context 总被引：2，自引：0，他引：2
Rainfall variability and changes in Southern Africa over the 20th century areexamined and their potential links to the global warming discussed. After a shortreview of the main conclusions of various experiments with Global AtmosphericModels (GCM) forced by increased concentrations of greenhouse gases for SouthernAfrica, a study of various datasets documents the observed changes in rainfall featuresat both daily and seasonal time steps through the last century. Investigations of dailyrainfall parameters are so far limited to South Africa. They show that some regionshave experienced a shift toward more extreme rainfall events in recent decades.Investigations of cumulative rainfall anomalies over the summer season do notshow any trend to drier or moister conditions during the century. However, closeexamination reveals that rainfall variability in Southern Africa has experiencedsignificant modifications, especially in the recent decades. Interannual variabilityhas increased since the late 1960s. In particular, droughts became more intense andwidespread. More significantly, teleconnection patterns associated with SouthernAfrican rainfall variability changed from regional before the 70s to near global after,and an increased statistical association to the El Niño – Southern Oscillation (ENSO) phenomenon is observed. Numerical experiments with a French GCM indicate that these changes in teleconnections could be related to long-term variations in the Sea-Surface-Temperature background, which are part of the observed global warming signal. 相似文献
5.
6.
对全球气候变化对地质灾害的响应关系,尤其是对滑坡和泥石流灾害的响应关系进行了综述。工业化革命以来,特别是近几十年来全球气候发生着重要的变化,全球几乎所有地区都经历着升温过程。全球气候变化对极端天气事件(极端降雨、气温升高、强风和洪水灾害)的影响尤为强烈,并且增加了地质灾害的发生风险。其中,水循环和气温的变化是影响地质灾害发生的直接因素。气温上升会导致大气层含水量升高、冰川冻土退化、海平面上升、蒸发作用增强;水循环变化会导致降雨频率、降水周期、降水强度的改变。日益增加的极端天气与同岩土体相互作用,导致了不同类型地质灾害的发生,严重威胁着人类的生活起居。 相似文献
7.
Indian Monsoon Variability in a Global Warming Scenario 总被引：4，自引：0，他引：4
The Intergovernmental Panel on Climate Change (IPCC) constituted by the World Meteorological Organisation provides expert guidance regarding scientific and technical aspects of the climate problem. Since 1990 IPCC has, at five-yearlyintervals, assessedand reported on the current state of knowledge and understanding of the climate issue. These reports have projected the behaviour of the Asian monsoon in the warming world. While the IPCC Second Assessment Report (IPCC, 1996) on climate model projections of Asian/Indian monsoon stated ``Most climate models produce more rainfall over South Asia in a warmer climate with increasing CO2', the recent IPCC (2001) Third Assessment Report states ``It is likely that the warming associated with increasing greenhouse gas concentrations will cause an increase in Asian summer monsoon variability and changes in monsoon strength.'Climate model projections(IPCC, 2001) also suggest more El Niño – like events in the tropical Pacific, increase in surface temperatures and decrease in the northern hemisphere snow cover. The Indian Monsoon is an important component of the Asian monsoon and its links with the El Niño Southern Oscillation (ENSO) phenomenon, northern hemisphere surface temperature and Eurasian snow are well documented.In the light of the IPCC globalwarming projections on the Asian monsoon, the interannual and decadal variability in summer monsoon rainfall over India and its teleconnections have been examined by using observed data for the 131-year (1871–2001) period. While the interannual variations showyear-to-year random fluctuations, thedecadal variations reveal distinct alternate epochs of above and below normal rainfall. The epochs tend to last for about three decades. There is no clear evidence to suggest that the strength and variability of the Indian Monsoon Rainfall (IMR) nor the epochal changes are affected by the global warming. Though the 1990s have been the warmest decade of the millennium(IPCC, 2001), the IMR variability has decreased drastically.Connections between the ENSO phenomenon, Northern Hemisphere surface temperature and the Eurasian snow with IMR reveal that the correlations are not only weak but have changed signs in the early 1990s suggesting that the IMR has delinked not only with the Pacific but with the Northern Hemisphere/Eurasian continent also. The fact that temperature/snow relationships with IMR are weak further suggests that global warming need not be a cause for the recent ENSO-Monsoon weakening.Observed snow depth over theEurasian continent has been increasing, which could be a result of enhanced precipitation due to the global warming. 相似文献
8.
Temporal-spatial climate change in the last 35 years in Tibet and its geo-environmental consequences 总被引：4，自引：0，他引：4
The climate change in Tibet has induced complex water resource and geo-environmental changes. Tibet is located in a unique
geographical zone with the characteristics of middle-low latitude, high altitude and very low average air temperature, and
the climate there has been changed both in time and in space under the effect of global warming. Except for two regions without
data, the changes of both air temperature and rainfall in the last 35 years in Tibet exhibit evident zonational patterns.
In general, air temperature increases higher from east to west, whereas rainfall changes from decrease to increase from south
to north. Except for some areas in southern Tibet, the general increase of rainfall accelerated the rate of water cycle, and
caused an increase in the gross amount of water resources in Tibet. Moreover, under the impact of climate change, the frequency
of occurrence of landslide and debris flow has slightly increased in the high mountain–canyon regions of eastern Tibet. Also,
the debris flow due to ice lake outburst has evidently increased in the plateau mountain–lake basin regions of southern Tibet.
By contrast, desertification in the western plateau–lake basin regions of northern Tibet has been intensified. 相似文献
9.
青藏高原沱沱河地区冻土融化深度预测的概率分析 总被引：2，自引：2，他引：0
多年冻土空间异质性和边界条件及土性参数的可变性,往往会导致了冻土变化预测的不确定性,全球气候变暖更加剧这一过程.以青藏高原沱沱河地区试验段冻土融化深度预测为例,提出了在全球气候变暖条件下,基于参数服从某一概率分布的确定性模型的概率分析方法,基于此方法进行了融化深度的概率预测.由含水量、干容重的概率分布和20组ATI(空... 相似文献
10.
Chew-Hung Chang 《Natural Hazards》2011,56(3):667-679
The 2007 Intergovernmental Panel on Climate Change (IPCC) Assessment Report 4 found an average increase in global surface
temperature of 0.74°C between 1906 and 2005. There is general agreement in the literature that the frequency of extreme precipitation
events in Southeast Asia will increase with global warming. In particular, the potential impact of associated storm hazards
will render the densely populated countries in Southeast Asia vulnerable to such changes in precipitation events. One main
adaptation strategy given such impending changes is preparedness. Using existing literature and historical meteorological
data, this paper establishes that Southeast Asia is indeed experiencing storms of higher intensities and more frequently.
Two case of extreme storm event in Southeast Asia, the extreme high rainfall event in December 2006 in Southern Johor and
Typhoon Vamei, are presented to consider the implications of the increased storm activities due to global warming. These two
examples also discuss the need for preparedness in adapting to the impact of global warming. 相似文献
11.
北极快速增暖背景下冰冻圈变化及其影响研究综述 总被引：1，自引：1，他引：0
北极具有独特的地理位置和战略地位,是当前全球变化研究的热点区域之一。北极增暖是全球平均值的两倍以上,被称为“北极放大”现象。在北极快速增暖背景下,冰冻圈尤其是海冰显著萎缩,对北极乃至中纬度天气气候产生深远影响。对北极快速增暖背景下冰冻圈主要要素（包括海冰、冰盖、冰川、积雪和冻土）时空变化特征及未来预估进行了综述,同时总结了海冰变化对北极气候系统（大气圈、水圈、岩石圈和生物圈）以及中纬度极端天气气候事件的影响。指出当前北极冰冻圈变化研究受观测资料缺乏及模式模拟不确定等问题限制,其机理及对中纬度天气气候影响机制仍存在争议。未来还需要加强北极地区的综合监测,提高模式对北极气候系统物理过程的模拟能力,进行多模式、多数据、多方法的集成研究。 相似文献
12.
Vulnerability from storm surges and cyclone wind fields on the coast of Andhra Pradesh,India 总被引：2，自引：0，他引：2
The results presented here are from a study conducted for the government of the state of Andhra Pradesh (GOAP) in India, as
part of a World Bank project on cyclone mitigation. A set of detailed maps were prepared depicting the Physical Vulnerability
(PV), specifically storm surge inundation zones are shown for frequent occurrence, 50-year return period, likely scenario
for global warming and extreme global warming. Similarly vulnerable areas from strong wind field from tropical cyclones (TCS)
are also presented for the same four parameters. Vulnerability zones are presented from a social point of view also based
upon certain socio-economic parameters that were included in determining the overall vulnerability of each Mandal in a coastal
district (a Mandal represents a group of villages and towns) include: population, senior citizens, women, children under different
age groups, type of housing, income level, cyclone shelters, hospitals and medical centres, schools and caste based population.
The study is about scenarios that could happen if global warming and the predicted intensification of TCS actually occur as
predicted by some numerical models. 相似文献
13.
Kazuyo Tachikawa Laurence Vidal Corinne Sonzogni Edouard Bard 《Quaternary Science Reviews》2009,28(13-14):1160-1170
The phase relationship between climate parameters during terminations gives insight into deglaciation mechanisms. By combining foraminiferal Mg/Ca and alkenone thermometers with planktonic and benthic foraminiferal δ18O, we determined the phase relationship between local sea surface temperature (SST) and global seawater δ18O changes in the Coral Sea in the Southwestern Pacific over the last 360 ka. The onset of the SST warming preceded the seawater δ18O change by several ka for Termination I, II and III. During Termination I, the SST warming started at 20 ka BP, earlier than atmospheric CO2 rise suggesting that the greenhouse effect was not the main trigger of this early warming. Compilation of 14C-dated SST records from the whole Pacific during Termination I reveals that the onset of the warming is generally earlier in the Southern and the tropical Pacific than in the North Pacific. This spatio-temporal warming pattern suggests linkage between the southern ocean and tropical Pacific. The early tropical warming could provide heat and moisture to the northern high latitudes, modifying radiative balance and precipitation over ice sheets at the onset of deglaciation. 相似文献
14.
南亚季风降水的双极振荡* 总被引：1，自引：2，他引：1
文章利用气象资料揭示在印度半岛南部和北部,南亚季风降水变化在10年尺度以上呈翘翘板变化形式;利用更长的季风降水资料,即300年的喜马拉雅山达索普冰芯降水记录和印度半岛南部石笋降水记录,发现印度南部和喜马拉雅山季风降水呈双极振荡行为。自1700年以来,喜马拉雅山,即印度北部(或印度半岛南部)季风降水经历了1700~1764年期间的减小(或增加)趋势,1764~1876年期间的增大(或减小)趋势,1876~2000年期间的减小(或增加)趋势。同时,发现印度半岛南部的季风降水同北半球温度变化具有相同的变化特征,而喜马拉雅山季风降水同北半球温度变化具有相反的变化特征。南亚季风降水的这种南北翘翘板变化形式,与跨赤道气流有密切的联系。 相似文献
15.
《地学前缘(英文版)》2015,6(6)
Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate change is a natural phenomenon,many research scientists are widely in agreement that the increase in temperature in the 20 th century is anthropologically related.The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally.In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness.This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia.The comparison of decadal variation of precipitation and temperature anomalies before the 1970 s found general increases which were mostly varying.But beyond the 1970 s,global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period.There are frequent changes and a shift westward of the Indian summer monsoon.Although precipitation is observed to be 70%below normal levels,in some areas the topography affects the intensity of rainfall.These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future.The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human,financial,infrastructure and food security of the region. 相似文献
16.
Aiming at the current climate status, i.e., drastic rise of atmospheric greenhouse gases and the apparent trend of global warming, the International Ocean Discovery Program (IODP), launched in 2013, proposed four scientific challenges, including the response of global climate to CO2 rise, the feedback of ice-sheet and sea-level to global warming, the dynamics of the mid- and low-latitude hydro-cycle, and the mechanism of the marine carbon-chemical buffering system. By August 2017, eight IODP expeditions of climate-related themes were implemented, focusing on the Neogene evolution of the monsoon system over Asia-Pacific-Indian and the West Pacific Warm Pool, with specific interests in the variabilities and mechanisms of the Asian Monsoon system on orbital-to millennial-scales, as well as the connections between Asian Monsoon and the uplift/weathering of the Tibetan Plateau on tectonic time scale. The planned IODP expeditions in the forthcoming two years will explore the Southern high-latitude climate histories of West Antarctic ice in the Cenozoic, and Southern Ocean currents and carbon cycle in the Cretaceous-Paleogene. In sum, during the current phase of IODP (2013-2023), our knowledge about the marine climate system would be greatly advanced via deciphering the past changes in tropical processes of Asian Monsoon and West Pacific Warm Pool, as well as in high-latitude factors of the West Antarctic ice. A better scientific background of natural variability would be provided, accordingly, for predicting the future tendency in climate change. In this context, China’s strategic directions include the global monsoon concept, the tropical forcing hypothesis, and in particular the climate effect of the Sunda Shelf. 相似文献
17.
国际南极冰盖与海平面变化研究述评 总被引：2，自引：1，他引：1
海平面上升是全球变暖的主要后果之一。尽管有少数冰川学家认为,气候变暖并不能确保雪积累量的显著增加,同时可能出现冰流的突然变化,因此南极冰盖在未来海平面变化中的作用存在很大的不确定性。但近几十年来南极半岛气温的急剧上升,已使大量的冰架崩解。冰架崩解并不对海平面产生真正的影响,但反映出南极洲气候与冰川存在急剧变化的可能。 相似文献
18.
Russell S. Crosbie James L. McCallum Glen R. Walker Francis H. S. Chiew 《Hydrogeology Journal》2012,20(2):245-261
In semi-arid areas, episodic recharge can form a significant part of overall recharge, dependant upon infrequent rainfall events. With climate change projections suggesting changes in future rainfall magnitude and intensity, groundwater recharge in semi-arid areas is likely to be affected disproportionately by climate change. This study sought to investigate projected changes in episodic recharge in arid areas of the Murray-Darling Basin, Australia, using three global warming scenarios from 15 different global climate models (GCMs) for a 2030 climate. Two metrics were used to investigate episodic recharge: at the annual scale the coefficient of variation was used, and at the daily scale the proportion of recharge in the highest 1% of daily recharge. The metrics were proportional to each other but were inconclusive as to whether episodic recharge was to increase or decrease in this environment; this is not a surprising result considering the spread in recharge projections from the 45 scenarios. The results showed that the change in the low probability of exceedance rainfall events was a better predictor of the change in total recharge than the change in total rainfall, which has implications for the selection of GCMs used in impact studies and the way GCM results are downscaled. 相似文献
19.
古风暴学是始于20世纪90年代的一门新兴学科，通过研究风暴活动的地质记录和历史文献资料，恢复器测之前几百年至数千年前的热带气旋活动规律。经过十几年的发展，逐渐形成一套包括研究领域、方法、技术与手段等比较完整的理论体系，成为第四纪古气候研究和过去全球变化的重要组成部分。古风暴学研究的替代指标包括：文字记载、特征的风暴事件沉积、海相化石组合、同位素地球化学组成等。这些指标单独使用时都有一定局限性。寻找新的替代指标，并运用多种指标综合分析方法提高古风暴事件的分辨率和可信度，是今后该学科发展的重要方向。已有的研究多侧重于古风暴频数的研究，今后应充分利用现代风暴潮理论的新进展，通过数值模拟与替代指标研究相结合，更准确地恢复古风暴强度。同时，应加强古风暴活动的全球对比研究，以揭示风暴活动与全球气候变化的关系，为在全球不断变暖背景下台风活动的情景预测提供依据。 相似文献
20.
本文根据30多个古气候分析实例,探讨中国热带MIS3气候波动的相位特征、变幅特征和周期特征.MIS3为回暖期,曾出现早、晚2个暖期,晚期比早期更暖.MIS3的气候与现今的气候相比较,东部热带以热湿为主,年均温比今高1°～2℃或2°～2.5℃,年降水量比今多700mm或400～500mm;西部热带以凉湿为主,年均温与今相似或约低1.5℃,年降水量比今多700mm左右.MIS3期间出现2个冷-暖-冷的旋回,平均周期为17.5ka,这与岁差周期大体相符.中国热带MIS3的气候波动不仅有万年尺度的地球轨道周期,也有千年尺度的周期,后者与太阳辐射总量本身的变化有关. 相似文献