Mechanism of evolution on winter-time natural convection cooling effect of fractured-rock embankment in permafrost regions

Recent researches indicate that the global climate really shows a warming trend[1―5]. The Intergovernment Panel on Climate Change (IPCC) predicts a 1.4℃―5.8℃ rise in the global surface temperature between 1990 and 2100 using the climate change forecast model[5]. During the same times, the climate in the Qinghai-Tibet Plateau will also bring about relevant changes. Recent predictions show that the air temperature of the Qinghai- Tibet Plateau will be a rise of 2.2℃―2.6℃ by 2050. Th…     

大气环流年代际变化对东亚北部冬季气温异常的影响

 利用NCEP资料1949～1999年间的地表气温(SAT)进行经验正交函数分解(EOF).得到的前2个模态均表明,20世纪70年代中期以后,东亚北部地区冬季气温增暖明显,发生了显著的年代际变化.这种气温的异常变化主要受到东亚冬季风的直接影响.近20多年来,北极涛动维持在正位相并持续增强,其对东亚冬季风的影响也越来越显著,东亚冬季风持续减弱,使得东亚北部地区冬季气温增暖.通过对SAT和SLP进行奇异值分解(SVD),结果表明北极涛动的持续增强可能是东亚北部地区冬季增暖的重要原因之一.     

全球变暖对中国新疆地区的可能影响及对策浅议

对于全球变暖所带来的各种影响,各界人士都给与了关注,但是非褒贬各异.新疆作为中国面积最大,环境最脆弱的省区,面临的问题,该采取什么措施,文章在了解最近几年来新疆气候、水文、生态环境变化的基础上就全球变暖在新疆的影响提出一些个人观点.     

Water-vapor source shift of Xinjiang region during the recent twenty years

The aim of this paper is to investigate the climate water-vapor sources of Xinjiang region and their shifts during the past 20 years. First, the principle and steps are roughly regulated to seek the water-vapor sources. Second, the climate stationary water-vapor transport in troposphere is calculated to distinguish where the water vapor comes from by ERA-40 reanalysis. In addition, the collocation between the transport and the atmospheric column water vapor content is analyzed. The results show that the major vapor comes from the west side of Xinjiang for mid-month of seasons, apart from July while the water vapor comes from the north or northwest direction. The water vapor sources are different for different seasons, for example, the Caspian Sea and Mediterranean are the sources in January and April, the North Atlantic and the Arctic sea in July, and the Black Sea and Caspian Sea in October, respectively. In recent ten years more water vapor above Xinjiang comes from the high latitudes and the Arctic sea with global warming, and less from Mediterranean in comparison with the case of 1973—1986. In fact, the air over subtropics becomes dry and the anomalous water vapor transport direction turns to west or southwest during 1987—2000. By contrast, the air over middle and high latitudes is warmer and wetter than 14 years ago.     

全球变暖机理探索

本文讨论了1900年至今的全球气候变化与巨行星会聚周期对应的科学事实,认为地球的能量并非只从太阳获取,地球具有电能的再生机制。地球是个带负电的准带电星球,地球是个大电容。地核能量通过断裂带向海洋传输过程中,其传输速度与太阳及行星运行周期有关。近期的地球气候变暖与巨行星运行到星下点对应地球赤道断裂带有关。因天体运行的规律是有章可循的,故能预测到气候变暖是暂时的现象。本世纪20年代开始全球气候将有变冷趋势,60年代全球气候又将变暖,重复新一轮的全球变暖周期。     

Global mean temperature changes during the last millennium

A synthetic study is made on the global or hemispheric mean temperature series for the last millennium worked out by Mann et al., Jones et al., Crowley and Lowery, and Briffa. The global mean temperature series reconstructed by using proxy data at 30 sites by Wang et al. and simulations from AD 1000 to 2000 by energy balance model are described and compared with the series of others. Wang's series gives greater variability and shows the highest correlation coefficient (0.83) with the simulation results. Uncertainties in the reconstructions and simulations are discussed. The errors in reconstructing a global mean temperature series according to 30 sites as used in the research are estimated. Wang's series indicate that temperature average for the 11th century is higher than the mean of the last millennium. It infers that the Medieval Warm Period predominated to some extent over the globe. However, the 20th century is no doubt the warmest century during the last millennium.     

气候变暖对黄淮海平原冬小麦生长及产量影响的数值模拟

利用改进的荷兰Wageningen农业大学的产量生态学模式SUCROS，模拟了气候变暖引起的温度升高和降水量变化对黄淮海平原冬小麦生长发育及产量的影响。结果表明：黄淮海平原中、北部地区，由于自然降水远小于小麦生育期的生理需水量，无灌溉条件下小麦生长相当困难；黄淮海平原南部地区，气温升高加快了冬小麦的生长发育速率，缩短了生育历程，在无土壤水分亏缺的理想状态下，适度升温有利于冬小麦生长及产量的提高；但在土壤水分亏缺时，温度升高，虽改善了冬小麦越冬条件，使其叶面积指数增高，CO2同化能力增强，但高温加大了土壤蒸发，使小麦生长中、后期水分亏缺加重，小麦绿叶同化能力降低，最终使产量下降。当气候变暖伴随降水量增大时，这一现象有所缓解。若气候变暖伴随降水减少，则产量下降加剧。模拟显示，流行于该区的农田林网可有效地改善农田小气候，提高小麦的水分利用率和干物质生长量。在气候变暖的严峻形势下，组建农林复合生态系统应作为一种可持续发展的农业经营策略加以推广应用。     

Precipitation variability in central Himalayas and its relation to Northern Hemisphere temperature

Agriculture, industry and hydroelectric power in south Asia are heavily dependent on the performance of the summer (June to September) monsoon rainfall, which provides 75—90% of the annual rainwater over most parts of the area. A weak monsoon year generally corresponds to low crop yields. And strong monsoon usually produces abundant crops, although too much rainfall may produce devastating floods. However, modeling efforts to forecast the monsoon have met with only moderate success[1]. Prev…     

黑碳气溶胶研究新进展

黑碳气溶胶是气溶胶的重要组成部分,在大气物理、大气化学、大气光学、大气光化学等过程中具有重要作用。近年来研究表明,黑碳气溶胶对于全球变暖、区域气候变化有重要贡献,黑碳气溶胶可能是影响全球变暖的第二大重要因子,其作用仅次于CO2。因此,应控制黑碳的排放。考虑到黑碳气溶胶在全球变暖、区域气候、环境与健康等方面的作用,研究和评价黑碳气溶胶的作用已十分必要和迫切。     

气候变暖和降水变化对地下生态过程的影响

地下生态学过程是指陆地生态系统地下部分结构、功能的动态变化过程,它与地上过程高度关联,是全面理解生态系统结构和功能,特别是对全球气候变化响应和适应机理的关键.气候变暖和降水变化是气候变化的两个重要方面,它们对地下生态学过程各个方面的影响复杂且重要,然而目前在这方面的综述文章并不多见.本文综述了气候变暖和降水变化对土壤碳收支、氮循环、土壤生物以及植物细根的周转等方面的研究进展,并在此基础上分析了相关研究领域的主要瓶颈,提出了一些亟待解决的科学问题,期望促进气候变化背景下地下生态学的发展.