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1.
Interannual variations of the monsoons have been studied utilising homogeneous rainfall records of 41 years (1951–1991) from Malaysia and upper air data of stations in Asia, Australia and Western Pacific. Sources of upper air data are U.S. Department of Commerce and Kuala Lumpur Northern Winter Monsoon Activity Centre. Extreme wet and dry years have been identified and the influence of ENSO on Malaysian annual rainfall has been discussed. Influence of ENSO on the performance of northern summer and winter monsoons has also been studied from Malaysian rainfall data. Further, regional circulation patterns associated with El Nino and La Nina years have also been identified. No linear trend has been found in the annual rainfall of 16 stations in Malaysia. Most El Nino years are associated with below median and La Nina years with above median rainfall at most stations in Malaysia. ENSO has greater influence over East Malaysia than peninsular Malaysia. Interannual variability of rainfall with reference to ENSO conditions has been discussed in details. Also, circulation features have been identified to foresee El Nino/La Nina events.  相似文献   

2.
1961—2008年若尔盖高原湿地的气候变化和突变分析   总被引：3，自引：0，他引：3  
利用1961—2008年若尔盖高原湿地境内的5个气象台站的逐月气象数据和玛曲水文站的径流数据,分析了近48a来若尔盖湿地的气候变化趋势,并应用M-K方法、累积距平和滑动t检验对年降水量和平均气温的气候突变进行了检测.结果表明:从1960年代的冷湿期,到1980年代中期到1990年代中后期的冷干期,再到1990年代末起增暖迅速进入暖干期,若尔盖湿地气候呈现较明显的暖干化趋势:一方面,总云量持续减少,日照时数上升,平均气温明显上升,气温日较差逐渐减小;另一方面,降水量、蒸发量、径流量总体都呈减少趋势,干燥指数也逐渐降低.秋季是若尔盖高原湿地气候发生暖干化最明显的季节,气候变暖主要是平均最低温度显著升高的贡献.日较差是蒸发量变化的最重要的影响因子,但低云量、气温、日照等的作用也不能忽视.年平均气温和降水量分别在1997年和1985年发生突变,分别转为迅速增暖和持续减少.  相似文献   

3.
The Monsoon Experiment is the core of the GARP Monsoon Subprogramme, which is a major international effort to achieve a better understanding of the Planetary monsoon circulation, the major seasonal perturbation of the general circulation of the atmosphere and the influence of the annual cycle of precipitation associated with the monsoon on the agriculture of the many populous nations of the region.This is a summary report of the International MONEX Planning Meetings, which were held in Yerevan, USSR, March 1973; Singapore, November 1974; New Delhi, March 1977; and Kuala Lumpur, February 1978.MONEX represents a group of observational studies during the First GARP Global Experiment (FGGE) over the South China Sea (December 1978), Arabian Sea (May–June 1979), and Bay of Bengal (July–August 1979). These periods will permit study of most of the significant aspects of the winter and summer monsoons. This is elaborated on in Sections 2 and 3.  相似文献   

4.
Data on recent variations in the seasonal extent of snow cover and sea ice, of the terminal position and volume of alpine glaciers, and of ground temperature profiles in permafrost areas are reviewed. The extent of seasonal snow cover and of sea ice has fluctuated irregularly over the last 15–20 years. There is no apparent response to global warming trends. In contrast, most glaciers retreated and thinned from the late 19th century until the 1960s and Alaskan permafrost temperatures have risen 2°–4° C per century. Recently, some glacier advances have been noted.  相似文献   

5.
Tim Bunnell 《GeoJournal》2004,59(4):297-305
Becoming the tallest building in the world in the mid-1990s, the Petronas Towers was the centre piece of an image of national progress and development that Malaysian authorities sought to project internationally. The release of Fox Movies' Entrapment in Malaysia in May 1999 provoked political outrage and popular disappointment at the way in which the Petronas Towers in Kuala Lumpur had been spliced alongside riverside ‘slums’ filmed in the town of Malacca some 150 km away. This paper provides a critical reading of the spliced scene in the movie. At one level, the angry response of the Malaysian Prime Minister, Dr Mahathir Mohamad, to the scene diagnoses a geopolitics of asymmetrical representational power. However, I show how Mahathir's criticism of Entrapment in Malaysia was as much a defence of domestic political legitimacy (and national economic investibility) as it was ‘opposition’ or ‘resistance’ to hegemonic ‘Western’ (mis)representation. In addition, while the material and symbolic work of reimaging Kuala Lumpur had sought to negate (neo)orientalist imaginings of ‘Asian’ cities, the controversial scene rendered visible environmental ‘underdevelopment’ that has no place in a modern (vision of) Malaysia. Entrapment thus performed something in inducing Malaysian cities and citizens to ‘clean up’ their act, to practice ‘fully developed’ ways of seeing, being and being seen. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

6.
青藏高原气候变化的若干事实及其年际振荡的成因探讨   总被引：1，自引：0，他引：1  
利用1961-2012年青藏高原88个气象台站逐月气温、降水以及温室气体等气候系统监测资料和CMIP5输出的未来气候变化情景数据,分析了近52年来青藏高原气候变化暖湿化的若干事实,揭示了其年际振荡与温室气体、高原加热场、高原季风、AO等气候系统因子的关系,预测了未来20~40年青藏高原可能的气候变化趋势。研究表明：近52年来青藏高原在总体保持气候变暖的趋势下自2006年以来出现了某些增暖趋于缓和的迹象,较全球变化滞后了8年左右;降水量的增加在青藏高原具有明显的普遍性和显著性,气候变湿较变暖具有一定的滞后性,降水量变化的5年短周期日趋不显著,而12年、25年较长周期逐渐明显且仍呈增多趋势。由于温室气体、气溶胶持续增加、高原夏季风趋强、ENSO事件和太阳辐射减少,青藏高原气候持续增暖但有所缓和;春季高原加热场增强、高原夏季风爆发提前且保持强劲,使得高原春、夏季和年降水量增加,而秋、冬季AO相对稳定少动,东亚大槽强度无明显变化,高原冬季风变化不甚显著,导致了高原秋、冬季降水量无明显变化。未来20~40年青藏高原仍有可能继续保持气温升高、降水增加趋势。  相似文献   

7.
In the present study, an investigation has been made to study the spatial and temporal variability in the maximum, the minimum and the mean air temperatures at Madhya Pradesh (MP), in central India on monthly, annual and seasonal time scale from 1901 to 2002. Further, impact of urbanization and cloud cover on air temperature has been studied. The annual mean, maximum and minimum temperatures are increased by 0.60, 0.60 and 0.62 °C over the past 102 years, respectively. Seasonally, the warming is more pronounced during winter than summer. The temperature decreased during the less urbanized period (from 1901 to 1951) and increased during the more urbanized period (1961 to 2001). It is also found that the minimum temperature increased at higher rate (0.42 °C) followed by the mean (0.36 °C) and the maximum (0.32 °C) temperature during the more urbanized period. Furthermore, cloud cover is significantly negatively related with air temperature in monsoon season and as a whole of the year.  相似文献   

8.
Stefan B. Velev 《GeoJournal》1996,40(4):363-370
This article attempts to analyse the current climatic variations based on air temperature and precipitation data from 18 stations for the 1916–1993 period. No substantial changes have been established in the annual air temperatures, averaged over the whole country's area, but there is evidence of late fall cooling and winter warming in the recent decade. A marked drought set in during 1982–1993, which in SW Bulgaria which reached a record level for the last 100 years both in terms of its duration and intensity. Climatolgical patterns contributing to these observations are discussed.  相似文献   

9.
1961-2012年辽宁省极端气温事件气候变化特征   总被引：3，自引：1，他引：2  
利用辽宁省52个气象台站逐日平均气温、 最高气温和最低气温数据, 使用国际通用的10种极端气候指数, 研究了1961-2012年辽宁省极端气温事件的气候变化特征. 结果表明: 年平均极端气温事件空间分布存在明显的地区差异. 时间尺度上, 1961-2012年辽宁省年及四季极端暖事件(暖昼日数、 暖夜日数、 夏季日数、 热带夜数和热浪持续指数)呈增加趋势, 极端冷事件(冷昼日数、 冷夜日数、 结冰日数、 霜冻日数和寒潮持续指数)呈减少趋势; 极端暖事件在20世纪90年代中期开始明显增加, 极端冷事件在20世纪80年代末期开始显著减少; 极端暖事件的变化速率要小于极端冷事件. 辽宁省气温日较差有增大的趋势, 极端暖(冷)事件的增加(减少)在秋季(冬季)最为显著. 空间变化上, 极端气温事件在全省基本都呈一致的增加或减少的分布. 多数极端气温事件均存在8 a左右的周期, 检测到的突变的时间大致在20世纪80年代中期到90年代末期. 20世纪80年代末期辽宁省气候变暖后, 极端暖事件和冷事件均有明显的增加和减少.  相似文献   

10.
Aquaculture of channel catfish is an industry with an annual worth of hundreds of millions of dollars. Catfish farms in the United States are, for the most part, confined to the south central region and in California. Their commercial success depends on a climate which produces a sufficiently long growing season and an abundant supply of shallow groundwater. The proximity to markets is also essential. The temperature range for maximum growth of the species is 24°C–29°C with the growth rate rapidly decreasing as the upper lethal temperature — about 35°C — is approached. Growth below 13°C is negligible.We review the thermal requirements for growth in catfish and examine the role that climate (air temperature and precipitation) plays in limiting the distribution of profitable fish farms. A model is constructed from these relationships which permits the prediction of changes of this distribution resulting from climate warming.  相似文献   

11.
Loss values from extremes in the U.S. and elsewhere have been more qualitativethan quantitative, but recent pressures for better information have led to newassessments and better estimates of financial losses from extremes. These pressureshave included concerns over potential impacts of more extremes due to global warmingfostered by ever increasing costs to the insurance industry and government from weather extremes; plus a series of massive losses during the past 15 years (drought of 1988–1989,Hurricane Andrew in 1992, and Midwestern 1993 floods). These recent assessmentsattempted to adjust data for societal changes over time and thus derived new and betterestimates of losses for seven major extremes than existed previously. Three extremeshave annual average losses in excess of a billion dollars (1998 dollars) includinghurricanes ($4.2 billion), floods ($3.2 billion), and severe local storms ($1.6 billion).One extreme and its adjusted losses exhibit upward trends (floods), but all others showno increases with time or temporal decreases (hail, hurricanes, tornadoes, and severethunderstorms). Annual national losses during 1950–1997 from the three major extremes, plus four others (hail, tornadoes, winter storms, and wind storms), collectively reveal no upward or downward trend over time, with an average annual loss of $10.3 billion. The quality loss values do not indicate an increase as has been postulated for global warming. The good news is that better estimates of impacts now exist, but the bad news is that they are still estimates and do not include sizable unmeasured losses. If accurate data on the economic impacts from weather extremes are seen as important for scientific research and policy-making for global warming, the U.S. needs a continuing program to adequately measure losses from weather extremes.  相似文献   

12.
About the observed and future changes in temperature extremes over India   总被引：1，自引：0，他引：1  
An attempt is made in the present study to analyse observed and model simulated temperature extremes over Indian region. Daily maximum and minimum temperature data at 121 well-distributed stations for the period 1970–2003 have been used to study the observed changes in objectively defined values of temperature extremes. In addition, an assessment of future scenarios of temperature extremes associated with increase in the concentration of atmospheric greenhouse gases is done using simulations of a state-of-the-art regional climate modelling system known as PRECIS (Providing Regional Climate for Impact Studies) performed to generate the climate for the present (1961–1990) and future projections for the period 2071–2100. Observational analysis done with 121 stations suggests the widespread warming through increase in intensity and frequency of hot events and also with decrease in frequency of cold events. More than 75% stations show decreasing trend in number of cold events and about 70% stations show increasing trend in hot events. Percentage of stations towards the warming through intensity indices of highest maximum temperature, lowest minimum temperature is 78 and 71% stations, respectively. Remaining stations show opposite trends, however, most of them are statistically insignificant. Observational analysis for India as a whole also shows similar results. Composite anomalies for monthly temperature extremes over two equal parts of the data period show increase (decrease) in the frequency of hot (cold) events for all months. In general, PRECIS simulations under both A2 and B2 scenarios indicate increase (decrease) in hot (cold) extremes towards the end of twenty-first century. Both show similar patterns, but the B2 scenario shows slightly lower magnitudes of the projected changes. Temperatures are likely to increase in entire calendar year, but the changes in winter season are expected to be prominent. Diurnal temperature range is expected to decrease in winter (JF) and pre-monsoon (MAM) months.  相似文献   

13.
The sea surface temperature (SST) variations play a veryimportant role in the genesis and maintenance of meteorological and oceanographic processessuch as monsoon depressions and subsequent floods, large-scale sea level fluctuationsand genesis of tropical cyclones. Many low lying coastal regions of South Asia are adjacentto river deltas and have large population. The dense population, poor economy and severalother socio-economic factors make these areas most vulnerable to the impact of climate change.Variability of sea surface temperature (SST) is importantas the duration and intensity of SST provide the basis for studies related to climatic changescenario. In this study an attempt has been made to estimate the recent SST trends in the coastalwaters of some cities, which lie on the Arabian Sea and Bay of Bengal. The annual andinterannual variability has also been studied. The SST variations have then been linkedwith the El Nino and La Nina events.The NOAA-NASA Pathfinder Advanced Very High Resolution Radiometer (AVHRR) SST fields from 1985-1998, created in the Jet Propulsion Laboratory(JPL), USA are used in this study. Here the quality of data is an important factor toobtain reliable estimates of Sea Surface Temperature (SST) trends and other related parameters.However, this is not possible with the conventional type data, due to low quality as wellas sparse data in the region. Though the satellite based SST climatologies have shorterobservation lengths, they can provide reliable estimates of recent SST variability overa large oceanic areas with sparse or no data.Increasing trend of SST is observed throughout all theseasons in the northern Arabian Sea extending from Oman to Karachi and Mumbai and furthersouth to Salalah and Colombo. However, in coastal islands stations further south ofIndia such as at Colombo the increment is not significant. Though the increasing trend in SSTduring winter is not significant, nevertheless it shows the increasing influence of coldspells on this Island. An interesting situation has been observed in the Bay of Bengal. On anaverage, increasing trends in the annual SST were observed in Visakhaputnam. But at thestations located in the northeastern part of Bay of Bengal, namely Hiron Point and Cox'sBazar reverse conditions are observed. In the Southern Bay of Bengal variations in SST isnot significant which reflects in the SST analysis of Chennai and Port Blair stations. Locationof these stations at lower latitudes (near by equator) probably is the reason for this insignificantchange. It has been found that the interannual mode of SST variations dominate the linear SSTtrends which is characterized by the El Nino Southern Oscillations (ENSO) scale cycle.  相似文献   

14.
新疆40a来气温、降水和沙尘天气变化   总被引：67，自引：10，他引：57  
何清  杨青  李红军 《冰川冻土》2003,25(4):423-427
根据1961-2001年新疆代表北疆的8个气象站、天山山区的8个气象站、南疆的8个气象站的实测资料, 分析了40 a来新疆气温、降水、沙尘暴、扬沙、浮尘年代际变化特征.结果显示: 40 a来新疆气温呈明显上升趋势, 后10 a(1991-2000年)比前30 a平均气温升高, 北疆偏高0.8℃, 南疆和天山山区均偏高0.℃; 降水变化的总趋势是增湿明显, 后10 a与前30 a相比降水增加, 南疆偏多20.4%, 北疆偏多11.3%, 天山山区偏多9.8%; 南疆与北疆各类沙尘天气年际变化趋势基本相似, 80年代以来呈减少趋势; 南疆沙尘暴、扬沙、浮尘总日数之和与同期的温度、降水在春季有相对较好的线性相关关系.  相似文献   

15.
Surface air temperature is one of the main factors that can be used to denote climate change. Its variation in the westerly and monsoon-influenced part of China (i.e., North-West and East China) were analyzed by using monthly data during 1961–2006 from 139 and 375 meteorological stations over these two regions, respectively. The method of trend coefficient and variability was utilized to study the consistency and discrepancy of temperature change over North-West and East China. The results suggest that whether for the annual or the seasonal mean variations of temperature, there were consistent striking warming trends based on the background of global warming over North-West and East China. The most obvious warming trends all appeared in winter over the two regions. Except for the period in spring, the annual and seasonal mean warming trends in North-West China are more obvious than those in East China. The annual mean temperature warming rates are 0.34°C per decade and 0.22°C per decade over North-West and East China, respectively. The average seasonal increasing rates in spring, summer, autumn, and winter are 0.22°C per decade, 0.24°C per decade, 0.35°C per decade, and 0.55°C per decade in North-West China, respectively. At the same time, they are 0.25°C per decade, 0.11°C per decade, 0.22°C per decade, and 0.39°C per decade in East China, respectively. The temperature discrepancies of two adjacent decades are positive over the westerlies and monsoonal region, and they are bigger in the westerlies region than those in the monsoonal region. The most significant warming rate is from the North-East Xinjiang Uygur Autonomous Region of China to West Qinghai Province of China in all seasons and annually over the westerlies region. The North and North-East China are the main prominent warming areas over the monsoonal region. The warming rate increases with latitude in the monsoonal region, but this is not the case in the westerlies region.  相似文献   

16.
殷宝玲  刘琪  王叶堂 《冰川冻土》2021,43(5):1383-1399
基于19个人工气象站1961—2017年风速风向实测数据对南极冰盖近地面风速时空变化和风向进行了分析。结果表明：近50年来,南极冰盖近地面各季节平均风速和年平均风速变化的空间模式基本一致。东南极0°~120° E沿海地区风速呈显著上升趋势;南极半岛气象站风速变化趋势各异,且变化速率相差甚大,但从区域平均结果来看,南极半岛年和季节平均风速均呈上升趋势。这与近几十来局地气温、气压变化及南半球环状模趋向于正位相发展有关。东南极受下降风和绕极东风影响,大部分地区盛行偏南风或偏东风,且频率较高风向稳定;而受天气活动影响,南极半岛风向复杂,主风向频率低,风向多变。  相似文献   

17.
1960-2003年新疆山区与平原积雪长期变化的对比分析   总被引：35，自引：17，他引：18  
崔彩霞  杨青  王胜利 《冰川冻土》2005,27(4):486-490
对新疆91个地面站44a(1960—2003年)的>0cm积雪日数、冬季最大积雪厚度、冬季降水量和冬季平均温度统计分析,结果发现:伴随着20世纪80年代以来明显的增温增湿变化,新疆积雪呈轻度增长趋势,90年代增加明显.积雪日数和厚度与冬季降水量呈正相关,但与冬季平均温度没有明显相关关系.将91个地面站分成24个山区站和67个平原站的进一步分析表明,山区积雪增幅大于平原,而平原的冬季温度和降水增幅大于山区.60年代和90年代山区和平原呈两个相反方向的同步变化(60年代少雪、少降水和降温;90年代多雪、多降水和增温),但幅度略有不同.70年代和80年代山区和平原无论积雪还是温度、降水量都呈现明显不同的变化.  相似文献   

18.
Direct information about climate change from meteorological surface air temperature records are available in India only since 1901 A.D. Meteorological surface air temperature (SAT) data for the period 1901–2006 from 49 sites in peninsular India have been combined with the geothermal data from 146 sites to extract a baseline (or pre-observational mean, POM) surface temperature prior to the existence of the observational record in the region. Periodicities of 5, 11 and 22 years in the SAT time series have little influence on the combined analysis to infer long-term climate change. The best estimate of the long-term average temperature for the 19th Century is 0.7 °C lower than the 1961–1990 mean temperature. Considering the additional warming of 0.38°C relative to the 1961–1990 mean over a 10-year window centred on the year 2000, the hybrid POM-SAT method suggests that the total surface warming in peninsular India from mid-1800s to early- 2000s is about 1.1 °C. The study provides new evidence for significant warming prior to the establishment of widespread meteorological stations in peninsular India.  相似文献   

19.
PRECIS模式对宁夏气候变化情景的模拟分析*   总被引：2，自引：0，他引：2  
使用英国Hadley气候中心区域气候模式PRECIS,分析了B2温室气体排放情景下,相对于气候基准时段1961~1990年宁夏2071~2100年(2080s)地面气温、降水量等的变化。结果表明:PRECIS模式能够很好地模拟宁夏气温的分布特征,对夏季最高气温的模拟效果好于冬季最低气温;较好地模拟出了宁夏降水南多北少的空间差异特征,且对夏季降水的模拟能力明显强于年均降水和冬季降水。相对于气候基准时段, 在B2情景下,2080s宁夏年平均、冬季和夏季平均气温均明显上升,宁夏北部和南部的部分地区气温上升幅度最大,夏季平均气温和最高气温上升幅度大于冬季平均气温和最低气温;未来宁夏年、冬季和夏季平均降水较基准时段均有所增加,但降水随年代际却呈减少趋势,由于气温和降水的气候变率加大,2080s宁夏出现高温、干旱、洪涝等异常天气事件的可能性增大。  相似文献   

20.
The thickness of varves in the sediments of Skilak Lake, Alaska, are correlated with the mean annual temperature (r = 0.574), inversely correlated with the mean annual cumulative snowfall (r = −0.794), and not correlated with the mean annual precipitation (r = 0.202) of the southern Alaska climatological division for the years 1907–1934 A.D. Varve thickness in Skilak Lake is sensitive to annual temperature and snowfall because Skilak Glacier, the dominant source of sediment for Skilak Lake, is sensitive to these climatic parameters. Trends of varve thickness are well correlated with trends of mean annual cumulative snowfall ( ) of the southern Alaska climatological division and with trends of mean annual temperature of the southern ( ) and northern ( ) Alaska climatological divisions. Trends of varve thickness also correlate with trends of annual temperature in Seattle and North Head, Washington ( , respectively). Comparisons of trends of varve thickness with trends of annual temperature in California, Oregon, and Washington suggest no widespread regional correlation. Trends of annual snowfall in the southern Alaska climatological division and trends of annual temperature in the southern and northern Alaska climatological divisions are reconstructed for the years 1700–1906 A.D. Climatic reconstructions on the basis of varve thickness in Skilak Lake utilize equations derived from the regression of series of smoothed climatological data on series of smoothed varve thickness. Reconstruction of trends of mean annual cunulative snowfall in the southern Alaska climatological division suggests that snowfall during the 1700s and 1800s was much greater than that during the early and mid-1900s. The periods 1770–1790 and 1890–1906 show marked decreases in the mean annual snowfall. Reconstructed trends of the annual temperature of the northern and southern Alaska climatological divisions suggest that annual temperatures during the 1700s and 1800s were lower than those of the early and mid-1900s. Two periods of relatively high annual temperatures coincide with the periods of low annual snowfall thus determined.  相似文献   

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