Groundwater recharge and climatic change during the last 1000 years from unsaturated zone of SE Badain Jaran Desert

The history of groundwater recharge and cli-matic changes during the last 1000 years has been estimated and reconstructed using environmental chloride from un-saturated zone profde in the southeast Badain Jaran Desert,NW China. By using a steady-state model for duplicate un-saturated zone chloride profiles, the long-term recharge at the site was estimated to be 1.3 mm yr^-1. From one profde,which reached the water table, the climatic change events of 10-20 years duration were well preserved. There were 3 wet phases and 4 dry episodes during the recent 800 years ac-cording to the peaks and troughs of recharge rate calculated via chloride concentration and moisture content. There was a dry episode before 1290 AD. At ca. 1500-1530 AD, which is an important date, there was an abrupt change from drought to wet conditions. At the beginning of the 1800s, local climate changed from wet to dry occurred and subsequently dete-riorated over the past 200 years,The unsaturated profile was compared with the Guliya ice core records.The agreement of wet and dry phases from 1200 to 1900 AD is quite good,whilst trends diverged during the last 100 years.It seems that the large-scale climate difference took place between mountain regions and the desert basin in NW China during the 20th century,which closely correspond to the water table reduction of some l metre.     

Vegetation evolution and millennial-scale climatic fluctuations since Last Glacial Maximum in pollen record from northern South China Sea

A large number of paleoclimate records reveal subMilankovitch climatic fluctuations on the millennial-scalesuperimposing on the Earth orbital cycles[1], such as theHeinrich ice draft events in the Atlantic (each intervalabout 7000–10000 a)[2,3], the Dansgaard/Oeschger (D-O)events (millennial-scale) in Greenland Ice Cores and theBond cycle composed of a Heinrcih event after severalD-O events[4]. At present, most recent work on millennial-scale climatic fluctuations focuses on the high lat…     

Temperature and precipitation in Mongolia based on dendroclimatic investigations

Recent tree-ring studies in Mongolia provide evidence of unusual warming that is in agreement with large-scal reconstructed and recorded temperaturec for the Northern Hemisphere and the Arctic.One Mongolian proxy record for temperature extends back over 1000 years and several others are over 350 years in length.Precipitation reconstructions based on thee rings reflect recent increases but also indicate that the increases are within the long-term range of varlations.Spectral analyses of recorded preciplta-tion data and the reconstructions support the hypotheses of quasi-solar periodicity in precipitation variation,previously suggested by others.     

太阳·地球耦合三法则

 日地空间的大尺度物理效应是解开气候变迁之谜的钥匙,也是研究复杂系统预报问题的关键.在此首先用几何方法求出图形解,给出大尺度地磁效应三法则:①蟹爪法则;②魔瓶法则;③软齿轮法则.应用这些法则讨论了长时标地球物理效应对地磁暴现象的作用机理.     

具任意裂纹的复合材料弹性平面周期焊接问题

应用平面弹性复变方法，研究了具任意裂纹的复合材料弹性平面周期焊接问题，通过周期Sherman变换,将其转化为带Hilbert核的奇异积分方程，并给出了解的存在惟一性定理．     

Holocene abrupt climate shifts recorded in Gun Nuur lake core, northern Mongolia

A continuous 7.44 m lake core was successfully drilled at Gun Nuur Lake, northern Mongolia, and analyses on environment magnetic parameters, organic matter content and organic δ^13C were conducted in an attempt to retrieve the Holocene chronosequence of climatic changes based on 6 AMS ^14C dates. We found that the Holocene climate in northern Mongolia has been alternating between cold (or cool)/wet conditions and warm/arid conditions, and also punctuated with a series of abrupt climate shifts. The abrupt climate shifts occurred around 1750, 2800, 4000, 5200, 7200, and 9200 aBP (^14C age), being chronologically correlative to those abrupt climatic events recorded in the high-latitude North Atlantic Ocean. The correlation indicates that the climatic changes in northern Mongolia were linked with those in the North Atlantic Ocean probably via the North Atlantic Oscillation-affected westerly winds. The strength and position of westerly winds might have modulated the Siberian-Mongolian high pressure system (winter monsoon), directly influencing the climate in China.     

用最大熵谱方法分析气候序列的周期

提出以正弦函数拟合序列的周期分量并进行周期分量显著性检验的方法。对南宁年平均气温序列和梧州年降水量序列进行了周期分析。     

贵州水稻气候资源及其种植区域划分

本文分析了贵州水稻气候资源和影响贵州水稻产量的主要气候问题,并在此基础上用热量和水分为指标,将全省划分成六个不同的水稻种植区,同时予以评述,从而为省内水稻专业化和区域化生产提供了气候依据。