Isotopic and chemical analyses of a temperate firn core from a Chinese alpine glacier and its regional climatic significance     

He Yuanqing  Yao Tandong  Theakstone W.H  Yang Meixue 《极地研究(英文版)》2000,11(2)

Mt. Yulong is the southernmost currently glacier-covered area in Eurasia, including China. There are 19 sub-tropical temperate glaciers on the mountain, controlled by the south-western monsoon climate. In the summer of 1999, a firn core, 10. 10 m long, extending down to glacier ice, was recovered in the accumulation area of the largest glacier, Baishui No. 1. Periodic variations of climatic signals above 7. 8 m depth were apparent, and net accumulation of four years was identified by the annual oscillations of isotopic and ionic composition. The boundaries of annual accumulation were confirmed by higher values of electrical conductivity and pH, and by dirty refreezing ice layers at the levels of summer surfaces. Calculated mean annual net accumulation from 1994/1995 to 1997/1998 was about 900 mm water equivalent. The amplitude of isotopic variations in the profile decreased with increasing depth, and isotopic homogenization occurred below 7. 8 m as a result of meltwater percolation. Variations of δ18O above 7. 8 m showed an approximate correlation with the winter climatic trend at Li Jiang Station, 25 km away. Concentrations of Ca2+ and Mg2+ were much higher than those of Na+ and K+ , indicating that the air masses for precipitation were mainly from a continental source, and that the core material accumulated during the winter period. The close correspondence of C1- and Na+ indicated their common origin. Very low concentrations of SO2-4 and NO3- suggest that pollution caused by human activities is quite low in the area. The mean annual net accumulation in the core and the estimated ablation indicate that the average annual precipitation above the glacier's equilibrium line is 2400 - 3150 mm, but this needs to be confirmed by long term observation of mass balance.  相似文献   

多种海啸触发类型的流固耦合数值模拟初步研究     

刘双庆  朱元清  薛艳  温艳玲 《地震地磁观测与研究》2007,28(5):130-137

利用有限元流固耦合理论来模拟二维、三维海啸触发阶段的动态过程,将海啸可能的触发类型分离出来独自模拟分析,并解决了触发过程中,流固计算可能失效而面临的问题,从形变图,压强图以及能量图多侧面地表达出流固耦合在海啸触发模拟中的可行性.由于不需要进行浅水波近似,因此所使用的计算方法和结果可推到较广的使用范围.  相似文献   

上海及其邻近地区上地幔间断面接收函数的研究   总被引：1，自引：1，他引：0  

王小平  朱元清 《地震地磁观测与研究》2007,28(5):150-154

利用上海及其邻近地区地震台网两个剖面上自2002年以来256个远震记录,提取得到高质量的接收函数,通过对这些接收函数的共转换点叠加得到研究区的间断面的分布及形态.研究结果表明,剖面上的上地幔间断面410 km,660 km间断面没有明显的起伏变化,从而证实了西太平洋俯冲带对中国东部的影响在东北、华北和华东有显著差别.  相似文献   

海啸传播模型与数值模拟研究进展   总被引：1，自引：0，他引：1  

温燕玲  朱元清 《地震地磁观测与研究》2007,28(5):143-149

海啸在浅水大陆架的传播问题由于其非线性作用和浅水效应而变得十分复杂,然而目前成熟的海啸传播理论及数值模拟结果在这方面与实际并不一致.本文比较分析了可用来模拟大陆架海啸传播的浅水波模型和数值方法,并提出对我国东海陆架边缘可能发生的近海海啸需要开展数值试验研究.  相似文献   

区域自然资源综合区划的方法探讨——以大连地区陆域自然资源综合区划为例   总被引：1，自引：0，他引：1  

潘贤君  胡宝清 《海洋地质与第四纪地质》1997,(3)

本文以适当面积为区划单元，采用定性与定量相结合的方法确定区划单元的主导资源和优势资源组合类型，再根据主导资源相同，资源组合相似的原则，自下而上地聚类归并分区。通过对大连地区陆域自然资源区划实践，证明该方法适用可行。  相似文献   

Impacts of Climate Warming on Alpine Glacier Tourism and Adaptive Measures:A Case Study of Baishui Glacier No.1 in Yulong Snow Mountain,Southwestern China     

王世金  何元庆  宋晓东 《中国地质大学学报(英文版)》2010,(2)

Alpine glaciers usually feature with best hydrothermal condition in mountain climate,and present beautiful glacier scenery,various glacier landforms,rich biodiversity,and easier accessibility,compared with continental glaciers or ice sheets.Nevertheless,Alpine glaciers are more sensitive to climate warming,and climate warming has seriously affected Alpine glaciers and surroundingenvironment.The quality and attractiveness of Alpine glaciers to tourism has been and will continue to be diminished with tourists...  相似文献   

Isotopic variations in precipitation at Bangkok and their climatological significance     

Yuanqing He  Hongxi Pang  W. H. Theakstone  Zhonglin Zhang  Aigang Lu  Juan Gu 《水文研究》2006,20(13):2873-2884

The stable isotopic composition of precipitation from low to mid latitudes contains information about changes of some climatic factors, such as temperature, precipitation and atmospheric circulation patterns. However, the isotopic variations in the area are very complicated because of the combined influences of these factors. Proper interpretation of the patterns of isotopic variations for palaeoclimate reconstructions in this area requires a detailed understanding of these complex stable isotope controls. The isotopic data (δ¹⁸O and δ²D) in precipitation at the International Atomic Energy Agency–World Meteorological Organization Bangkok station were collected and analysed because of the relatively long and unbroken isotopic records and the particular geographical location. The isotopic variations at Bangkok have strong seasonal patterns owing to distinct source regions in different seasons. In summer, the remote sources of water there can influence the δ¹⁸O values significantly, which is verified by the simple Rayleigh model. In winter, the mixing of isotopically distinct air masses with different origins, i.e. the continental and oceanic air masses, accounts for the isotopic variations. In the transition periods of the Asia–Australia monsoon, namely in May and October, the local vapour contribution may play a role in the isotopic ratios. On the interannual time‐scale, the influences of El Niño–southern oscillation (ENSO) and the Indian Ocean dipole (IOD) on isotopic composition are examined. The indications are that both the ENSO and IOD indices have a significant correlation with the δ¹⁸O ratios, and that the δ¹⁸O ratio in summer rains is significantly more enriched (depleted) during the warm (cold) phase of ENSO/IOD events. All the results suggest that it is useful for us in understanding the water cycling process and may be helpful in palaeoclimate reconstruction in this monsoon region. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Chinese Continental Paleocene-Eocene Boundary and Its Correlation     

WANG Yuanqing  TONG Yongsheng  LI Qian 《《地质学报》英文版》2011,85(2):443-451

Recent paleontological, paleomagnetic and carbon isotopic investigations have provided new evidence supporting placement of the Chinese terrestrial Paleocene–Eocene boundary at the base of the Lingcha Formation in the Hengyang Basin, Hunan Province, and within the upper part of the Nomogen Formation in the Erlian Basin, Inner Mongolia. Based on mammalian and ostracod biostratigraphic data, the boundary can also be roughly correlated with the contacts between the Baoyue and Huayong formations in the Sanshui Basin of Guangdong, the Qingjiang and Xinyu formations of Jiangxi, the Fourth Formation of the Funing Group and the Dainan Formation in northern Jiangsu, and the Dabu and Shisanjianfang formations in the Turfan Basin of Xinjiang.  相似文献   

Regional disparity and convergence of China’s inbound tourism economy   总被引：1，自引：0，他引：1  

Shuxin Wang  Yuanqing He  Xueding Wang  Guofeng Zhu  Weihong Cao 《中国地理科学(英文版)》2011,21(6):715-722

Comprehending regional characteristics and influencing factors of China’s inbound tourism economy is important to make effective policies that will help inbound tourism develop harmoniously and shrink regional disparity. This paper studied the regional disparity and convergence of China’s inbound tourism economy during 1996–2008 with the methods of σ-convergence, club convergence and β-convergence. The results indicate that 1) inbound tourism receipts per capita (ITRPC) of the whole country, the eastern, central and western regions presented the rapid increasing trend; 2) ITRPC of the whole country was characterized by convergence; 3) the eastern region presented club convergence, but the central and western regions did not show this trend; 4) the star-hotel levels and investment in fixed assets for the tourism industry per capita had a same trend to growth rates of ITRPC, promoting inbound tourism development, and there was no difference among the 31 provinces (municipalities) in the mainland of China; 5) but the proportion of employed persons in the tourism industry accounting for total population and the proportion of the tertiary industry accounting for GDP had a reversal trend to growth rates of ITRPC, shrinking the provincial disparity in inbound tourism economy, and there were differences between the developed provinces and the developing provinces. Based on these analyses, we put forward some suggestions for the developing provinces to speed up inbound tourism economy.  相似文献   

Regional summer temperature decrease against global warming in China, landform effect?     

Aigang Lu  Deqian Pang  Yuanqing He  Hongxi Pang  Tianming Wang  Jianping Ge 《山地科学学报》2007,4(1):086-090

The data of 160 national meteorological observatory (NMO) stations with long-term monthly temperature data for China were analyzed in this study to show the basin-centered summer temperature decrease against global warming in the past half century. The summer and winter isotherm structures of 1950s and 1990s worked out by interpolation show the isotherm structure variations: the isotherm structure generally moves northward in winter, but in summer it is characterized with separate high-temperature and low-temperature centers and the isotherm structure moves inward the centers with global warming, indicating that the temperature in the highland areas increases but that in the lowland areas decreases in the summer of the duration. The possible mechanism of the basin-centered temperature decrease in summer is discussed in this paper.  相似文献