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1.
MULTI-SCALE ANALYSES OF SURFACE AIR TEMPERATURE VARIATIONS FOR THE NORTHERN HEMISPHERE AND CHINA DURING THE LAST ONE HUNDRED YEARS 总被引：1，自引：0，他引：1
Using multi-resolution theory of wavelet analysis,this paper studies the multi-scale structureof surface air temperature variations for the Northern Hemisphere and China during the last onehundred years.The results show that the climatic variations for the Northern Hemisphere can bedescribed as 3 hierarchies corresponding to the larger-scale changes.They are the cold period be-fore 1919,the warm period from 1920 to 1978 and the warmer period after 1979.The larger-scalehierarchical changes obviously show qualities of climate jump.The years 1920 and 1979 are thejump points of climate change.The surface air temperature variations for China are not entirelyanalogous to the Northern Hemisphere,and the main contrasts are that China is in the cold periodafter 1955 and the jump point of warming is 1987.The surface air temperature variations for theNorthern Hemisphere and China during the last one hundred years obviously show the hierarchicalstructure of multi-scale changes and the qualities of climate jump. 相似文献
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本文以小波分析的多分辨分析理论为基础，建立了一个自适应的多分辨数据滤波器。该滤波器不仅具有传统方法所不具有的局部化、多层次、多分辨的优点，而且对于突变点的判断也象M-K方法一样的精确。此外，该滤波器还具有可以同时判别多个突变点而不改变原时间序列的大尺度结构的优点。本文的应用表明:中国近百年来的气温变化主要经历了三个持续近30年的冷暖交替，它们分别是1919年以前的偏冷期；1920年至1954年的偏暖期和1955年至1986年的偏冷期。对应于这种较大时间尺度的气候演变，中国的气温变化表现出了十分明显的突变特性，其冷暖交替的突变点分别发生在1920年、1955年和1987年。对应于较小时间尺度的气候演变来说，中国近百年来的气温变化则增加了更多冷暖交替的层次结构和突变点。云南近百年来的气温变化与中国的气温变化是基本一致的，但与北半球和全球的气温变化并不完全一致，其中最主要的差异是北半球和全球的气温变化在1955年至1978年是一个极弱的偏冷期，1979年发生明显增暖的突变，而云南和中国的气温变化在1955年至1986年则是一个极强的偏冷期，从1987年开始才出现明显增暖的突变。 相似文献
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An analysis has been conducted of the multi-hierarchical structure and jump of temperature variation for the globe, China and Yunnan Province over the past 100 years using an auto-adaptive, multi-resolution data filter set up in You, Lin and Deng (1997). The result is shown below in three aspects. (11 The variation of global temperature in this period is marked by warming on a large scale and can be divided into three stages of being cold (prior to 1919), warm (between 1920 and 1978) and warmer (since 1979). Well-defined jumps are with the variation in correspondence with the hierarchical evolution on such scale, occurring in 1920 and 1979 when there is the most substantial jump towards warming. For the evolution on smaller scales, however, the variation has shown more of alternations of cold and warm temperatures. The preceding hierarchical structure and warming jump are added with new ones. (2) The trend in which temperature varies is much the same for China and the Yunnan Province, but it is not consistent with that globally, the largest difference being that a weak period of cold temperature in 1955-1978 across the globe was suspended in 1979 when it jumped to a significant warming,while a period of very cold temperature in 1955-1986 in China and Yunnan was not followed by warming in similar extent until 1987. (3) Though there are consistent hierarchical structure and jumping features throughout the year in Yunnan, significant changes with season are also present and the most striking difference is that temperature tends to vary consistently with China in winter and spring but with the globe in summer and fall. 相似文献
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CLIMATIC JUMP FROM LATE 1970S TO EARLY 1980S AND ITS EFFECT 总被引：1，自引：0，他引：1
By use of the moving T test to do research on the interdecadal climate jump of the NorthernHemisphere sea level pressure.500 hPa height and North Pacific sea surface temperature,wefound that in recent 50 years an obvious interdecadal climate jump existed at the late 1970s to theearly 1980s.There is significant difference before and after the jump in terms of the NorthernHemisphere sea level pressure,500 hPa height and North Pacific sea surface temperature.Furthermore,the focus is then placed on the effect of the jump on temperature and rainfall inChina. 相似文献
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By use of the moving T test to do research on the interdecadal climate jump of the Northern Hemisphere sea level pressure.500 hPa height and North Pacific sea surface temperature,we found that in recent 50 years an obvious interdecadal climate jump existed at the late 1970s to the early 1980s.There is significant difference before and after the jump in terms of the Northern Hemisphere sea level pressure,500 hPa height and North Pacific sea surface temperature.Furthermore,the focus is then placed on the effect of the jump on temperature and rainfall in China. 相似文献
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中国、北半球和全球的气温突变分析及其趋势预测研究 总被引：37，自引：0，他引：37
本文采用均值差异假设检验研究了中国、北半球和全球气温历史序列的突变现象。分析表明，中国气温从本世纪以来，在４０年代末扣年代初曾出现一次由暖到冷的突变。北半球和全球均曾在１９世纪末和本世纪２０年代发生了突变现象。功率谱分析表明，气温的突变指数曲线具有明显的周期性。一系列比较研究证明，按照分析出的突变点将气温序列分段建模，无论数值误差还是变化趋势，效果均优于整段序列的模型。所以，对未来气温变化趋势作预测，应首先搞清楚未来会处在怎样的气候阶段中，会不会出现突变。研究表明，本文叙述的均生函数累加延拓的时序建模方案，对气温序列有很好的拟合和预测效果。 相似文献
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采用1951～2003年26个气象台站的夏季气温资料对我国东北地区夏季气温变化特征进行了分析。结果表明:近50多年来我国东北地区夏季气温主要经历了冷期、相对正常期和暖期3个阶段,夏季升温趋势达到0·15℃/10a,远超过全球、北半球、东北亚夏季的增暖程度。其对全球气候变暖的响应,一方面表现在夏季变暖、平均气温升高;另一方面表现在夏季气温变率加大;第三,气候变暖使东北夏季低温冷害明显减少、异常高温气候明显增多,但在变暖形势下局部发生低温冷害的现象仍然存在。 相似文献
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Climate Change in China from 1880 to 1998 and its Impact on the Environmental Condition 总被引：27，自引：0，他引：27
The global mean surface air temperature (SAT) or the Northern Hemisphere mean SAT has increased since the late nineteenth century, but the mean precipitation around the world has not formed a definite tendency to increase. A lot of studies showed that different climate and environmental changes during the past 100 years over various regions in the world were experienced. The climate change in China over the past 100 years and its impact on China's environmental conditions needs to be investigated in more detail.Data sets of surface air temperature and atmospheric precipitation over China since 1880 up to the present are now available. In this paper, a drought index has been formulated corresponding to both the temperature and precipitation. Based on three series of temperature, precipitation, and drought index, interdecadal changes in all 7 regions of China and temperature differences among individual regions are analyzed. Some interesting facts are revealed using the wavelet transform method. In Northeast China, the aridification trend has become more serious since 1970s. Drought index in North China has also reached a high value during 1990s, which seems similar to that period 1920s–1940s. In NorthwestChina, the highest temperature appeared over the period 1930s–1940s. Along the Yangtze River valley in central eastern China and Southwest China, interdecadal high temperature occurred from 1920s to 1940s and in 1990s, but the drought climate mainly appeared from 1920s to early 1940s. In South China, temperature remained at a high value over the period 1910s–1940s,but the smaller-scale variation of drought index was remarkable from 1880 to 1998. Consequently, the quasi-20-year oscillation (smaller-scale variation) and the quasi-70-year oscillation (secular variation) obviously exist in temperature and precipitation series in different regions over China.Climate change and intensified human activity in China have induced certain environmental evolutions, such as the frequency change of dust-storm event in northern China, no-flow in the lower reaches of the Yellow River and the runoff variation in Northwest China. On the other hand, frequent floods along the Yangtze River and high frequency of drought disaster have resulted in tremendous economic losses in the last decade in China. The primary reason for these happenings may be attributed to the evolution of the monsoon system in East Asian. 相似文献
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The NPO/ NAO and interdecadal climate variation in China 总被引：8，自引：0，他引：8
This article discusses the interannual variation of the North Atlantic Oscillation (NAO) and North Pacific Oscillation (NPO), its relationship with the interdecadal climate variation in China which is associated with the climate jump in the Northern Hemisphere in the 1960’s, using the data analyses. It is clearly shown that both the amplitudes of the NAO and NPO increase obviously in the 1960’s and the main period of the oscillations changes from 3-4 years before the 1960’s to 8-15 years after the 1960’s. Therefore, interdecadal climate variation in China or the climate jump in the 1960’s is closely related to the anomalies of the NAO and NPO. 相似文献
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The wavelets and hierarchies of the climate system 总被引：1，自引：0，他引：1
Summary Wavelet analysis of global mean temperature data, the drought-flood data of the past 500 years in China, and the temperature time series of Shanghai, highlights the following: (1) the climatic wavelets depend on the hierarchies of a climate system; (2) for different time scales or hierarchies, a climate system may have different catastrophic points and periods; (3) for different time scales or hierarchies, variation of the Southern Hemisphere temperature has an obvious phase-lag compared with that of the Northern Hemisphere and the catastrophe points also lag behind; (4) in a cold-warm period, the cold semi-period of the Northern Hemisphere is obviously longer than the warm one; (5) for different hierarchies or time scales, there exists a phase-lag for the droughtflood variation in China moving gradually with latitude from north to south. Finally, a new technique of climate diagnosis, the phase curve of wavelets, is put forward in this paper.With 6 FiguresSupported by Chinese NKPFR. 相似文献
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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
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Previous studies have shown that there are several indices of global-scale temperature variations, in addition to global-mean surface air temperature, that are useful for distinguishing natural internal climate variations from anthropogenic climate change. Appropriately defined, such indices have the ability to capture spatio-temporal information in a similar manner to optimal fingerprints of climate change. These indices include the contrast between the average temperatures over land and over oceans, the Northern Hemisphere meridional temperature gradient, the temperature contrast between the Northern and Southern Hemisphere and the magnitude of the annual cycle of average temperatures over land. They contain information independent of the global-mean temperature for internal climate variations at decadal time scales and represent different aspects of the climate system, yet they show common responses to anthropogenic climate change. In addition, the ratio of average temperature changes over land to those over the oceans should be nearly constant for transient climate change. Hence, supplementing analysis of global-mean surface temperature with analyses of these indices can strengthen results of attribution studies of causes of observed climate variations. In this study, we extend the previous work by including the last 10 years of observational data and the CMIP3 climate model simulations analysed for the IPCC AR4. We show that observed changes in these indices over the last 10 years provide increased evidence of an anthropogenic influence on climate. We also show the usefulness of these indices for evaluating the performance of climate models in simulating large-scale variability of surface temperature. 相似文献
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青藏高原及其四周的近代气候变化 总被引：24，自引：10，他引：24
本文首先研究了近千年来高原及其四周的气候变化,表明青藏高原是百年尺度气候变化的“启动区”,并用有近百年记录的Leh和Srinagar两站间的温度垂直递减率与降水距平百分率的10年滑动平均求相关,结果表明高原上的降水与气温垂直变率密切相关,降水多的年代高原内部温度高、外部低,反之亦然,完成一个振荡的周期约40年。其次分析了近30多年高原及其四周的气候变化,发现在北半球降温的60年代随着行星西风的加强,背风下沉区降水明显减少,向风区则增多。到了70年代高原北部夏季风开始增强,沙漠区降水开始增多。最后根据以上分析结果对中国西部至本世纪末的气候变化趋势作了初步预测,认为中国西部至少到本世纪末将继续升温,高原东西两侧的降水呈现“东升西降”的态势。 相似文献
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An aridity trend in china and its abrupt feature in association with the global warming 总被引：1，自引：0，他引：1
Fu Congbin 《大气科学进展》1993,10(1):11-20
A distinct aridity tread in China in last 100 years is presented by applying a linear fitting to both the climate re-cords and the hydrological records, which is supported by evidence of environmental changes and seems to be associ-ated with a global warming trend during this period.The Mann Kendall Rank statistic test reveals a very interesting feature that the climate of China entered into a dry regime abruptly in about l920’s, which synchronized with the rapid warming of the global temperature at almost the same time.According to an analysis of the meridional profile of observed global zonal mean precipitation anomalies during the peak period of global warming (1930-1940), the drought occurred in whole middle latitude zone (25oN-55oN) of the Northern Hemisphere, where the most part of China is located in. Although this pattern is in good agreement with the latitude distribution of the difference of zonal mean rates of precipitation between 4 × CO2 and 1 × CO2 simu-lated by climate model (Manabe and Wetherald, 1983), more studies are required to understand the linkage between the aridity trend in China and the greenhouse effect.The EOF analysis of the Northern Hemisphere sea level pressure for the season of June to August shows an ab-rupt change of the time coefficient of its first eigenvector from positive to negative in mid-lP^s, indicating an enhancement of the subtropical high over Southeast Asia and the western Pacific after that time. This is an atmos-pheric circulation pattern that is favorable to the development of dry climate in China. 相似文献
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In recent years,a large number of papers on the climatic sudden change have been presented.From the viewpoint ofclimatic sudden change,two methods of studying climatic sudden change are applied in this paper.The Northern Hemi-sphere land temperature(NHLT)during 1851—1984,China temperature(CT)during 1873—1990 and the NorthernHemisphere sea-level pressure(NHSLP)at each grid point during 1899—1987 are analyzed by the moving T-test.Theresults show that there exist two climatic sudden changes in the 1920s and the 1950s during the past 100 years,and thenfeatures of circulation for the two sudden changes are discussed by the NHSLP data. 相似文献
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20世纪90年代末东亚冬季风年代际变化特征及其内动力成因 总被引：10，自引：4，他引：6
为纪念陶诗言先生对东亚冬季风研究的杰出贡献,本文利用我国测站、NCEP/NCAR和ERA-40/ERA-Interim再分析资料分析了我国冬季气温和东亚冬季风在20世纪90年代末所发生的年代际跃变特征及其内动力成因。分析结果表明:从20世纪90年代末之后,我国冬季气温和东亚冬季风发生了明显的年代际跃变。从1999年之后,随着东亚冬季风从偏弱变偏强,我国冬季气温变化从全国一致变化型变成南北振荡型（即北冷南暖型）,并由于从1999年之后我国北方冬季气温从偏高变成偏低,故冬季低温雪暴冰冻灾害频繁发生,同时,我国冬季气温和东亚冬季风年际变化在此时期从以往3～4 a周期年际变化变成2～8 a周期;并且,结果还表明了东亚冬季风此次年代际变化是由于西伯利亚高压和阿留申低压的加强所致。本文还从北极涛动（AO）和北半球准定常行星波活动的动力理论进一步讨论了此次东亚冬季风年代际跃变的内动力成因及其机理,结果表明:从20世纪90年代末之后,北半球冬季准定常行星波在高纬地区沿极地波导传播到平流层加强,而沿低纬波导传播到副热带对流层上层减弱,这造成了行星波E-P通量在高纬度地区对流层和平流层辐合加强,而在副热带地区对流层中、上层辐散加强,因而导致了北半球高纬度地区从对流层到平流层纬向平均纬向流和欧亚上空极锋急流减弱,而副热带急流加强,这造成了AO减弱和东亚冬季风加强。 相似文献
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屠其璞 《南京气象学院学报》1991,(3)
本文在分析100多年来北半球平均气温长期变化基本特征的基础上,讨论了北半球气温变化对我国气候变化的影响。结果表明,我国大范围气温距平与北半球平均气温有显著的正相关,长江中下游和华北平原的温度距平值平均为北半球平均气温距平的1.4-1.6倍。还表明,我国降水距平分布与北半球气温变化也有一定的联系。在北半球平均气温偏高和偏低年份,欧亚地区500hPa环流特征的差异是显著的。这表明,我国大范围气候距平与北半球平均气温距平的统计相关是有一定的物理基础的。 相似文献
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北极涛动(Arctic Oscillation,AO)是北半球热带外地区大气环流变率的主导模态,对北半球以及区域尺度气温变化具有重要影响。AO可在没有外强迫条件下通过波流相互作用形成,因此它被认为是全球气候系统内部变率的重要组成部分。研究年代际尺度上AO的变化及其气候影响,可加深对当前北半球气候变化规律的物理理解,也可为预估未来年代际尺度上气候变化及其不确定性提供科学依据。本文从AO影响东亚冬季风年代际变化的物理机制、AO对北半球冬季气温长期趋势的贡献、AO年代际影响的不确定性三个方面出发,简要回顾和总结了近年来有关年代际尺度上冬季AO时空变化及其对北半球气候影响的研究成果,并初步展望一些值得继续深入研究的问题。 相似文献