Characteristics and Environmental Significance of pH and EC in Summer Rainfall and Shallow Firn Profile at Yulong Snow Mountain,Lijiang City,China

The seasonal and inter-annual variations of pH and EC(electrical conductivity) at Yu-long(玉龙) Snow Mountain,Lijiang(丽江) City,are sensitive to precipitation variations and are important indicators of the atmospheric environment.The pH of summer rainfall at Lijiang City ranges from 6.7 to 7.4,and alkaline mineral salts dominate the variations of rainfall acidity.pH values in theshallow firn profile at Baishui(白水) Glacier No.1 range from 5.6 to 6.3,and EC values from 2.4 to 7.3 μs/cm.The ranges are lower than ...     

Observed Glaciohydrological Changes in China's Typical Monsoonal Temperate Glacier Region since 1980s

Under the background of significant climate warming since the 1980s,the glaciers in China's monsoonal temperate glacier region respond to the warming intensely.Based on the glaciohy-drological observations at some typical glaciers from Mts.Yulong(玉龙) and Gongga(贡嘎) of Heng-duan(横断) Mountains Range in the southeastern Tibetan plateau,the glaciohydrological changes in the temperate glacier region since the 1980s were investigated.First,the glacier terminus exhibited an accelerating retreat.Second,as the glaci...     

云南丽江旅游气候舒适度分析

利用丽江1954-2009年的月气温、降水、相对湿度、风速、日照时数等影响旅游气候舒适度的气象资料, 对其进行年际、年内变化规律分析. 在计算其温湿指数THI、风效指数K和着衣指数ICL的基础上, 构建了一个新的综合气候舒适度评价模型, 分析计算了丽江市综合旅游气候舒适度, 划分出适宜于旅游的季节分布. 结果表明: 该地3-11月均较适宜旅游, 其中最佳旅游舒适期为5-9月; 2000年以来, 气温升高、风速降低、降水量减少、湿度下降的暖干趋势, 有利于吸引更多的游客, 并增加了游客在出游期间的舒适度; 冬春季节气温的升高, 使得全年中适宜旅游的时间在增加, 对旅游业发展有促进作用.     

祁连山区气候变化的区域差异特征及突变分析

利用8个气象站的气温和降水资料,运用一元回归分析法和5年趋势滑动,进行了气候变化的趋势分析,结果表明:祁连山区在20世纪80年代中后期气温持续升高,90年代以后明显变暖,其中秋、冬季升温幅度较大;60年代降水量最少,之后逐渐增多,80年代达到最多,90年代又减少,2000年以来又明显增多;气温变化在空间上表现为南北差异,以黑河干流为界,中东部升温幅度从南到北呈增大趋势,而中西部从南到北呈减小趋势;降水变化的空间差异也明显,东部表现为东西差异,降水量增加幅度从东到西呈减小趋势,而中、西部表现为南北差异,降水量增加幅度从南到北呈减小趋势。在此基础上,利用滑动T检验法、Cramer法、Mann-Kendall法进行气候突变分析,结果表明:祁连山区气温突变比降水突变明显,不同方法检验的结果比较一致;春、夏季气温在1997年发生突变,而秋、冬季在1985年左右发生突变。     

新疆叶尔羌河冰川洪水考察取得重要成果

由中国科学院兰州冰川冻土研究所,新疆自治区水利厅及中国科学院新疆地理研究所等单位组成的新疆叶尔羌河冰川洪水考察队,在1985年、1986年工作的基础上,于1987年5月至6月继续就此项课题在喀喇昆仑山进行了野外考察工作。今年是三年来考察时间最长的一年,也是取得成果最大的一年。全队工作人员在当地维吾尔族群众的协助下,在极其险恶的自然环境中,克服了重重困难,收集到大量极其珍贵的科学资料,为南疆生产建设和填补这个地区的科学空白,做出了突出的成绩和贡献。 这次考察队的组成是:队长由张祥松同志担任,副队长由由希尧、李念杰、王万祥同志担任。考察队总人数38人,其中专业人员中,水文气象13人,冰川4人,地质地貌3人,测绘3人,遥测预警系     

1900-2007年横断山区部分海洋型冰川变化

横断山区7条海洋型冰川近百年进退速度变化呈现出以退缩为总趋势的阶段性变化,具体表现为20世纪初至1930s的冰川稳定,1930s-1960s的冰川后退,1970s-1980s的冰川稳定或减速后退,20世纪80年代中期以来的冰川后退,这与我国、北半球及横断山区同期的气候变化呈明显对应,展现出冷干阶段冰川稳定或前进、暖湿阶段后退的态势,但各冰川的变化幅度因纬度位置、坡向、冰川规模、局地环境等而存在明显差异.1982/83年大、小贡巴冰川、海螺沟冰川冰舌段的消融水当量分别为2710mm、3139 mm和5281 mm,1990/91-97/98期间海螺沟冰川冰舌段的年均消融水当量为6157 mm,比1982/83年增加了876 mm.2002年夏季白水1号冰川的积雪消融量由于表碛覆盖较少表现出明显的随海拔升高而降低的特征,平均消融水当量为1086.25 mm,2008.9-19.10.13期间白水1号冰川物质平衡花竿的观测表明,花竿布设区域10月6号左右转入物质积累期.期间日均积累深为1cm,折合水当量5mm.     

黑河下游地区柽柳沙丘的气候与环境记录

对黑河下游地区柽柳沙丘沉积剖面进行AMS¹⁴C定年及沉积物粒度和Hg含量的综合分析,探讨了该区域从18世纪中期到21世纪初的气候与环境变化。结果表明:沙丘沉积物以细沙为主,粒度频率分布曲线呈明显的单峰形态,反映了单一的风力沉积作用;>100 μm的粗颗粒含量变化很好地指示了该区域冬季风的强弱变化,并记录了小冰期末期以来气候转暖的过程以及现代暖期中两个相对寒冷时期——20世纪10-20年代和50-60年代。沙丘沉积物中Hg主要来源于人类的工业活动,剖面Hg含量存在3个峰值,分别对应18世纪末的西班牙美洲地区银矿开采、19世纪中后期的北美淘金热、二次世界大战及战后经济复苏。此外,剖面中有两个样品Hg含量异常升高,其原因可能是1815年和1883年印尼的两次大规模火山喷发而引起的全球Hg沉降增加。     

基于历史文献的1470-2008年中国西北地区气候干湿序列分区重建

基于历史文献中的旱涝灾害记录,采用5级制划分的旱涝灾害等级,使用系统聚类法将中国西北地区19个站点划分为7个分区,利用湿润指数公式重建了西北地区7个分区1470-2008年的年分辨率干湿变化序列,比较分析了各分区干湿气候变化的阶段特征、周期性及跃变现象。结果表明：重建序列信度较高,可用作气候干湿变化研究。西北地区7个分区1470-2008年干湿变化存在着11 a、25~35 a和80~100 a的3类周期变化。其中,11 a和25~35 a的两个周期变化在整个分析时间段内表现得较为稳定;80~100 a的周期变化则表现的较不稳定。世纪尺度和气候代尺度的跃变信号各区皆有出现,位于研究区两边的陕西和玉树地区出现最少,宁夏和格尔木地区次之;位置居中的兰州、张掖、西宁等地区跃变信号出现最多,是气候干湿变化的敏感地带。检测出的干湿跃变信号主要集中在17世纪前后,近百年气候干湿变化则相对稳定。     

Variations of δ^18 O in Precipitation along Vapor Transport Paths

Three sampling cross sections along the south path starting from the Tropics through the vapor passage in the Yunnan-Guizhou Plateau to the middle-low reaches of the Yangtze River, the north path from West China, via North China, to Japan under the westerlies, and the plateau path from South Asia over the Himalayas to the northern Tibetan Plateau, are set up, based on the IAEA (International Atomic Energy Agency)/WMO global survey network and sampling sites on the Tibetan Plateau. The variations, and the relationship with precipitation and temperature, of the δ^18 O in precipitation along the three cross sections are analyzed and compared. Along the south path, the seasonal differences of mean δ^18 O in precipitation are small at the stations located in the Tropics, but increase markedly from Bangkok towards the north, with the 51so in the rainy season smaller than inthe dry season. The δ^18 O sovalues in precipitation fluctuate on the whole, which shows that there are different vapor sources. Along the north path, the seasonal differences of the mean δ^18 O in precipitation for the stations in the west of Zhengzhou are all greater than in the east of Zhengzhou. During the cold half of the year, the mean δ^18 O in precipitation reaches its minimum at Uriimqi with the lowest temperature due to the wide, cold high pressure over Mongolia, then increases gradually with longitude, and remains at roughly the same level at the stations eastward from Zhengzhou. During the warm half of the year, the δ^18 O values in precipitation are lower in the east than in the west, markedly influenced by the summer monsoon over East Asia. Along the plateau path, the mean δ^18 O values in precipitation in the rainy season are correspondingly high in the southern parts of the Indian subcontinent, and then decrease gradually with latitude. A sharp depletion of the stable isotopic compositions in precipitation takes place due to the very strong rainout of the stable isotopic compositions in vapor in the process of lifting over the southern slope of the Himalayas. The low level of the δ^18 O in precipitation is from Nyalam to the Tanggula Mountains during the rainy season,but δ^18 O increases persistently with increasing latitude from the Tanggula Mountains to the northern Tibetan Plateau because of the replenishment of vapor with relatively heavy stable isotopic compositions originating from the inner plateau. During the dry season, the mean δ^18 O values in precipitation basically decrease along the path from the south to the north. Generally, the mean δ^18 O in precipitation during the rainy season is lower than in the dry season for the regions controlled by the monsoons over South Asia or the plateau, and opposite for the regions without a monsoon or with a weak monsoon.     

玉龙山温冰川浅冰芯记录现代指示意义

１９９９年夏季首次在玉龙山最大的白水１号冰川积累区钻取了一支穿透整个粒雪层的１０ｍ冰芯,获取了近期数年的气候环境记录,深度７．８ｍ以上δ＾１８Ｏ周期性波动变化特性明显,通过与可溶性离子,电导率和ｐＨ值,以及粒雪中污化冰层位置的对比分析,可鉴别出５个平衡年度的冰雪层,每年平均净积累折合水当量约９００ｍｍ。由于融水渗浸的影响产生“均质化作用”,δ＾１８Ｏ变化幅度随深度增加而逐渐减小,在７．８ｍ以下,δ