中国近45年来气候变化的研究

利用１９５１～１９９５年约４００站的月平均气温、降水和１９６１～１９９５年２００余站的最高和最低气温、相对湿度、总云量和低云量、日照时数、蒸发、风速和积雪日数和深度以及０～３．２ｍ共８层土壤温度等资料,对近４５ａ来中国气候变化特征作了一个较全面的分析研究。本文作为第一部分,分析了平均气温、最高最低气温、降水、相对湿度和日照的气候变化规律。其余要素的变化规律以及中国气候变化的可能机制将在第二部分中加以讨论。     

甘肃近40年来气温变化的研究

利用 196 0～ 1999年甘肃省 15站的月平均气温 ,平均最高、最低气温 ,极端最高、最低气温等资料 ,对近 4 0年来甘肃省气候变化特征作了分析研究。结果显示 :1985年以前甘肃年平均气温变化是平稳的 ,以后急剧增温 ,且增温并不是主要由冬季增温造成的。1985年以前是平均最低气温升高 ,以后平均最高气温也在升高 ,所以 1985年以后的气温变暖不完全是以最低气温变暖为主形成的     

CLIMATE CHANGE IN CHINA AND ITS INFLUENCE ON AGRICULTURE PRODUCTION IN THE LAST 40 YEARS

Using the meteorological data set for 1951—1990 over 160 stations,a series of 10-year running mean curves oftemperature and precipitation averaged for the country and its 7 climate regions,as well as for each season,are obtainedand analyzed.The six aspects of main results can be summarized about the climate change in China and its influence onagriculture production in the last 40 years.     

CLIMATE CHANGE AND NATURAL VEGETATION IN CHINA

The climate change scenarios due to the human activity for East Asia and China by 2050 have been estimated bymeans of a simple global social-economic-climate-impact model combined with seven GCMs.The climate change sce-narios present that the annual mean temperature might increase obviously,by about 1.4℃,and the annual total precipi-tation might increase by about 4% in whole China in comparison with the present climate.The change of the precipita-tion might be much smaller than that of the temperature.The potential impacts of human activity-induced climate change on natural vegetation in China were estimated us-ing the vegetation-climate model developed specially for Chinese vegetation types and different climate change scenariosderived from seven GCMs for 2050.All scenarios suggest a great change in natural vegetation although details of pre-dicted types vary among the scenarios.There will be a northward shift of the vegetation types,with increase in the arealextent of tropical rainforests and decrease of the cold temperate coniferous forest and tundra.Consequently,consideringthese changes and shifts,especially in combination with the likely negative balance of precipitation andevapotranspiration,the moisture stress,i.e.,less water availability arises,the possible influences of climate change onChinese agriculture is also assessed roughly in this paper.     

GCM STUDIES ON ANTHROPOGENIC CLIMATE CHANGE IN CHINA

Impacts of human activities on climate change as simulated by the general circulation models(GCMs)in China for the recent ten years have been summarized and reviewed in this paper.Theresearches show that it might be getting warmer over China due to the greenhouse effects.Theatmospheric circulation and precipitation also might be changed due to the greenhouse effects.Theassessments and evaluations of the models over the globe and China have also been presented in thispaper.     

近50年来中国气候变化特征的再分析

利用国家气象中心最近整编的中国 74 0个站逐日资料 ,通过对中国温度、降水、湿度、风速、气压这 5个基本气象要素变化特征较为全面的分析 ,揭示了近 5 0a来中国气候变化的一些新特征。得到的新结果有 :(1)近 5 0a来 ,全国平均气温在 2 0世纪 80年代以后上升更为明显 ;西南低温区在 90年代以后温度也处于上升状态 ;夏季的长江中上游出现明显的降温趋势。 (2 )全国平均年总降水量波动略有减少 ,但 90年代以后夏季降水增加明显 ,尤其是长江以南地区 ,而华北、东北地区降水显著减少 ,体现了夏季风的减弱。 (3)全国平均相对湿度的变化和降水相似。(4 )中国几乎全部地区的风速都在显著减小 ,冬、春季和西北西部最明显 ,该区 90年代的年平均风速比 5 0年代减少约 2 9%。风速大幅减小主要是由于亚洲冬、夏季风的减弱。 (5 )全国平均的海平面气压在增高 ,尤其是北方的冬季 ,这和中国风速的大幅减小有关。     

北半球增暖对我国气侯的影响

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。     

西北地区地质气候变迁的初步研究

根据地质学考察材料分析，西北地质气候变迁的基本特征是非常寒冷的大冰期与温暖的大间冰期反复交替出现，以温暖气候为主。第一次大冰期为震旦纪大冰期，第二次为第四纪大冰期     

中国近80年来气候变化特征及其形成机制

自 2 0世纪 2 0年代以来 ,中国地区 4 0和 90年代出现了 2个暖期及 5 0～ 6 0年代相对冷期。最近的 90年代的最暖年 (1998年 )或 5a滑动平均气温几乎已达或略高于 4 0年代的最暖年 (194 6年 )或 5a滑动平均气温。变暖最明显是北方地区 (黑龙江和新疆北部 ) ,而 35°N以南和 10 0°E以东地区自 5 0年代以来存在一个以四川盆地为中心的变冷带 ,虽然 90年代有变暖趋势 ,但基本达到 4 0年代暖期气温。中国降水则以 2 0年代为最少 (192 9年最少 ) ,5 0年代为多水年代 ,以后缓慢减少 ,70年代以后变化不大 ,但多雨带在 80年代及以后由华北南移到长江中下游。195 1～ 1990年 ,大部分地区气温和降水呈负相关 ,在东北和长江—黄河间存在 2个负相关中心 ,表明北方是变暖变旱 ,江淮间是变冷变湿。这些气候变化特征和全球气候变化相比较 ,除北方外 ,变暖期明显的滞后于全球变暖 ,并且出现变冷带等明显差异。文中还综述了用诊断和数值模拟方法对影响中国变化的气候自然变化和人类活动影响 (热岛效应和气溶胶影响 )的研究结果。我们认为 ,以上提出的 3种人类活动对中国气候变化有明显影响 ,特别是工农业发展造成的气溶胶增加是四川盆地气温变冷的主要原因。     

辽宁省近48年来气候变化研究

利用 1 95 1～ 1 998年辽宁全省 2 5个气象站的月平均气温、降水量、平均最高、最低气温等资料 ,对辽宁省近 48年和近 1 0年的气候变化作了较为全面的分析     

IMPACTS OF CLIMATE CHANGE ON CROPPING SYSTEM AND ITS IMPLICATION FOR AGRICULTURE IN CHINA

Based on the analyses on amplitudes of historical variation of temperature and precipitation inthe past 500 years and latest 100 years,according to the regional climate change scenarios forChina estimated by composite GCM,the potential impacts of climate change on cropping systemsin China in future are simulated and assessed using the cropping system model developmentspecially for the Chinese cropping patterns.It is shown that under the projected future climatechange by 2050 the most parts of the present double cropping area would be replaced by thedifferent triple cropping patterns while the current double cropping area would shift towards thecentral part of the present single cropping area.More explicitly,the northern boundary of triplecropping area would shift from its current border at the Changjing River to the Huanghe River,ashift of more than 5 degrees of latitude.And the shift of multiple cropping areas leads to asignificant decrease of single cropping area.Furthermore,considering the changes mentioned above in combination with the likely negativebalance of precipitation and evapotranspiration and,therefore,increase of moisture stress(i.e.less water availability),as well as the possible increase of heat stress disaster and decrease of LGS(length of growing season),the potential implication of climate change for agriculture in China arealso analyzed roughly in this paper.As a result,however,it is still very difficult to reach a specific conclusion that the futureclimate change will he favorable or unfavorable to farm in China because of the complicated Chinesefarming patterns,the complex-various social and economic environment of agriculturaldevelopment and,especially,a great scientific uncertainties in the investigation/prediction ofclimate change.     

CHANGE TRENDS OF EXTREME CLIMATE EVENTS IN CHINA

The variations of extreme climate events such as cold wave, typhoon, hot and cold days havebeen discussed using the recent 45-year data. The reductions of nationwide cold wave activities andannual cold day number in northern China all have close relationship with warming winters,especially during 1980s and early 1990s. Decrements of annual hot day number are associated withcooling summers. The typhoon variation has connection with the tropical Pacific sea surfacetemperature conditions. The increments of drought/flood events since 1980s may be connectedindirectly with climate warming up significantly since 1980s. The climate variability of theseextreme climate events has decreased with time since 1980s.     

中国近5Oa来日最低气温的时间演变特征

利用1951～2000年全国241个测站1、4、7、10月(分别代表冬、春、夏、秋四季)及年平均的日最低气温资料，将全国划分为8个区域，并对不同区域在不同季节的日最低气温的变化特征进行了研究，通过研究发现：在全球气候变暖的背景下，日最低气温的增温是极为显著的，尤其是80年代中期之后，北方地区的增温比南方地区和青藏高原更加明显。70年代中期前后，日最低气温发生了近50a来的第一次变暖突变，此次变暖的趋势并不明显，而是以波动的形表现出来，80年代中期之后，出现了趋势极为明显的第二次变暖突变。通过对不同季节资料的研究还发现，在南方及青藏高原地区夏季日最低气温有下降的趋势。     

华南地区近40年降水的气候特征

利用１９５１－１９９４年华南地区１５个站的月降水量资料，探讨了这一地区近４０年来降水的气候特征。结果表明：（１）华南地区年降水量的变化存在一定的阶段性和周期性，５０年代和７０年代及９０年代前期降水相对偏多，６０年代和８０年代降水相对偏少。近４０年来降水量的变化趋势呈抛物线型，总的来持，前２０年少，后２０年略有增多。（２）降水变化具有明显的周期性振动，年和汛期降水的主周期为７－１１年，前汛斯和后汛期     

中国西北地区最高、最低气温的非对称变化

利用中国西北地区4个台站1932～1992年月平均最高气温(Tmax)、最低气温(Tmin)及气温日较差(DTR),1971～1992年总云量及低云量资料,分析了西北干旱区最高、最低气温的非对称变化和可能影响因子,并与华北地区、中国东部及北半球进行了比较。发现中国西北地区普遍存在非对称变化现象,可分为3种类型:①西北东部型,以西安、兰州为代表,Tmax显著下降,最大达-0.31℃/10a;Tmin显著上升,最高为0.41℃/10a;②西北中部型,以安西为代表,Tmax和Tmin都显著下降,但Tmax下降幅度大于Tmin;③西北北部型,以乌鲁木齐为代表,Tmax和Tmin都显著上升,但Tmin上升幅度大于Tmax。Tmax下降主要表现在夏季,Tmin上升主要表现在冬季,DTR在所有季节均显著下降,最大为-0.79℃/10a,冬季、春季、秋季及年下降幅度较大,夏季较小。与华北地区和中国东部相比,西北地区非对称变化的幅度更大,DTR大1～4倍。也大于北半球的变化幅度。总云量与DTR,Tmax有显著的负相关,东部高于中部和北部,最高可达-0.92,低云量的影响不大。     

A STUDY ON THE VARIATIONS OF CIRCULATION PATTERN IN THE NORTHERN HEMISPHERE AND CLIMATE CHANGE IN CHINA FOR THE RECENT 100 YEARS

The time series of annual frequency of the circulation patterns W,C,E in the Northern Hemisphere and annual mean temperature of Beijing (T_B),Shanghai (T_S) and the whole country (T_C) in the period 1891-1990 are expanded as a long-term tendency,a periodic function and a random function.The coherence between circulation and temperature is calculated and analyzed.The abrupt change of circulation and temperature in the last 100 years is revealed with the methods of the accumulated anomalous curves,the signal/noise ratio as well as the Mann-Kendall test.The correlations between anomalous circulation and climate are discussed with some explanations.     

THE MONSOON PRECIPITATION VARIATION IN THE CLIMATE CHANGE

First,studies on the East Asian monsoon simulation were reviewed.Then the monsoon precipitation change in thepaleoclimate was simulated and analyzed.This paper also analyzed and simulated the interannual changes of monsoonprecipitation and their relations with the sea surface temperature (SST) changes.Finally,the simulated monsoon precipi-tation change in the CO_2-induced climate change was discussed.     

GCM STUDIES ON ANTHROPOGENIC CLIMATE CHANGE IN CHINA*

Impacts of human activities on climate change as simulated by the general circulation models (GCMs)in China for the recent ten years have been summarized and reviewed in this paper.The researches show that it might be getting warmer over China due to the greenhouse effects.The atmospheric circulation and precipitation also might be changed due to the greenhouse effects.The assessments and evaluations of the models over the globe and China have also been presented in this paper.     

海南岛最高和最低气温的非对称变化

利用海南岛具有46年资料的13个站点1959-2004年1月、4月、7月、10月及年平均温度、平均最高最低温度、极端最高最低温度,研究海南气温变化的气候特征,结果表明,海南岛最高最低气温变化在空间分布,线性增温趋势的稳定性、倾向率和突变现象均有明显的非对称性特征：最高气温变化的空间分布表现为北高南低,而最低气温变化的空间分布表现为南高北低;各季节的平均最低气温的线性趋势均稳定,极端最低气温在冬季和夏季线性增温趋势稳定,而各季的平均、极端最高气温增温趋势均不稳定;最低气温的倾向率在各个季节或年平均上比最高气温的倾向率大得多,冷季的线性倾向率明显大于暖季;平均最高气温在四季均不存在明显突变,而平均最低气温则均有突变。     

温室效应引起的中国区域气候变化的数值模拟Ⅱ:中国区域气候的可能变化

使用RegCM2区域气候模式单向嵌套澳大利亚CSIRO R21L9全球海-气耦合模式,进行了温室气体CO2加倍对中国气候变化影响的数值试验研究。该文为第2部分,对敏感性试验结果进行的分析。分析表明:由于温室效应,中国区域的地面气温特别是在冬季和北方将有明显升高,区域年平均的升高值为2.5℃;同时区域内日最高和最低气温将明显上升,日较差将减小。结果还表明,在CO2倍增条件下,中国区域降水将呈增加趋势,区域年平均的增加值为12％;以夏季的增加率最大,其次为冬季。中国汛期降水将呈现出“三类雨型”出现频率增多的趋势。南方的大雨日数将有所增加。此外,生成和影响中国的台风数目也将有所增加。温室气体的增加同时对环流场产生影响,如导致500 hPa高度场的升高。