Variability of atmospheric freezing level height derived from radiosonde data in China during 1958–2005 and its impact to cryosphere changes     

YanJun Guo  YinSheng Zhang 《寒旱区科学》2011,3(6):0485-0490

Atmospheric air temperature data from 92 stations in China’s radiosonde network were used to analyze changes in the freezing level height (FLH), glacier snow line, and ice edge from 1958–2005 (48 years) and to examine the impact of these changes on the cryosphere. In general, the FLH, glacier snow line, and ice edge exhibited latitudinal zonation, declining from south to north. Trends in the FLH, glacier snow line, and ice edge showed spatial heterogeneity during the study period, with prevailing upward trends. Temporally, the FLH, glacier snow line, and ice edge trends differed on various time scales.  相似文献   

喜马拉雅山中东段蒙达扛日冰川水文与物质平衡观测研究     

王帅帅  周石硚  郑伟 《冰川冻土》2011,33(5):1146-1152

2007年7—9月,在喜马拉雅山中东段蒙达扛日冰川进行了水文和物质平衡的同步观测.结果表明：观测期间,蒙达扛日冰川表现为物质负平衡,冰川消融集中在7月和8月中上旬.观测的70 d内,花杆区冰川物质平衡量为-435～-711 mm,日平均值为-6.2～-10.2 mm.d-1,冰川的总物质平衡量为-355 mm.蒙达扛日...  相似文献   

应用SAR特征匹配方法估计音苏盖提冰川表面流速   总被引：4，自引：3，他引：1  

蒋宗立  刘时银  许君利  王欣  莫宏伟 《冰川冻土》2011,33(3):512-518

喀喇昆仑山区冰川因位于高海拔地区且远离人类正常活动的区域,使得连续的表面流速的地面观测很难实施,因此,对该区域冰川运动机理研究相对比较少.采用日本高级陆地观测卫星携带的相控阵型 L 波段合成孔径雷达(Advanced Land Observing Satellite,Phase Array L-band Synthet...  相似文献   

天山乌鲁木齐河源1号冰川径流对气候变化的响应分析   总被引：10，自引：6，他引：4  

焦克勤  叶柏生  韩添丁  井哲帆  杨惠安 《冰川冻土》2011,33(3):606-611

利用天山乌鲁木齐河源1号冰川1959-2006年的气象、冰川物质平衡和1980-2006年的水文资料,分析了其冰川径流的变化.结果表明:由于1996年以来的显著升温,导致了1号冰川水文点径流主要受夏季气温变化的控制,冰川物质损失对径流的补给作用已超过了降水的作用.1996-2006年与1980-1995年相比,夏季气温...  相似文献   

Decadal‐Scale Changes of the Ödenwinkelkees,Central Austria,Suggest Increasing Control of Topography and Evolution Towards Steady State          下载免费PDF全文

Jonathan L. Carrivick  Katie Berry  Martin Geilhausen  William H.M. James  Christopher Williams  Lee E. Brown  David M. Rippin  Steve J. Carver 《Geografiska Annaler: Series A, Physical Geography》2015,97(3):543-562

Small mountain glaciers have short mass balance response times to climate change and are consequently very important for short‐term contributions to sea level. However, a distinct research and knowledge gap exists between (1) wider regional studies that produce overview patterns and trends in glacier changes, and (2) in situ local scale studies that emphasise spatial heterogeneity and complexity in glacier responses to climate. This study of a small glacier in central Austria presents a spatiotemporally detailed analysis of changes in glacier geometry and changes in glaciological behaviour. It integrates geomorphological surveys, historical maps, aerial photographs, airborne LiDAR data, ground‐based differential global positioning surveys and Ground Penetrating Radar surveys to produce three‐dimensional glacier geometry at 13 time increments spanning from 1850 to 2013. Glacier length, area and volume parameters all generally showed reductions with time. The glacier equilibrium line altitude increased by 90 m between 1850 and 2008. Calculations of the mean bed shear stress rapidly approaching less than 100 kPA, of the volume–area ratio fast approaching 1.458, and comparison of the geometric reconstructions with a 1D theoretical model could together be interpreted to suggest evolution of the glacier geometry towards steady state. If the present linear trend in declining ice volume continues, then the Ödenwinkelkees will disappear by the year 2040, but we conceptualise that non‐linear effects of bed overdeepenings on ice dynamics, of supraglacial debris cover on the surface energy balance, and of local topographically driven controls, namely wind‐redistributed snow deposition, avalanching and solar shading, will become proportionally more important factors in the glacier net balance.  相似文献   

高山冰川多时相多角度遥感信息提取方法   总被引：1，自引：0，他引：1  

都伟冰  李均力  包安明  王宝山  王双亭 《测绘学报》2015,44(1):59-66

提出一种多角度遥感影像的冰川信息提取方法。通过"全域—局部"的阈值分割方法获取短时期内不同时相的遥感影像的冰雪边界,结合地形信息和多时相遥感影像的太阳角度信息,联合消除山体阴影对冰川的遮挡,并以多期影像的最小冰雪边界作为最佳冰川边界。以托木尔峰西侧冰川为研究对象,采用2009—2010年4个时相的遥感影像提取冰川信息。结果表明多角度遥感提取的冰川边界效果好,能有效地排除积雪与山体阴影的干扰。  相似文献   

基于纹理特征的SAR影像各拉丹冬冰川信息提取     

仲伟凡  唐远彬  殷腾箐 《测绘与空间地理信息》2015,(10):178-180

冰川面积是监测冰川变化信息的重要参数。本文以各拉丹东地区为例,根据冰川区域特有的纹理特征,选取时间间隔为35天的ENVISAT ASAR干涉对,利用灰度共生矩阵提取纹理特征,通过波段组合进行监督分类,进而提取研究区冰川面积。同时以Landsat TM光学影像为依据,评价利用纹理特征提取结果的精度。研究表明:基于纹理特征并利用SAR影像提取冰川面积的方法是可行的,为提取冰川信息提供了又一可靠手段。  相似文献   

Spatial and temporal variations of albedo on nine glaciers in western China from 2000 to 2011          下载免费PDF全文

Jie Wang  Baisheng Ye  Yuhuan Cui  Xiaobo He  Guojing Yang 《水文研究》2014,28(9):3454-3465

This research demonstrates the spatiotemporal variations of albedo on nine glaciers in western China during 2000–2011, by the albedo derived from two types of datasets: Landsat TM/ETM + images and MOD10A1 product. Then, the influence factors of glacier albedo and its relationship with glacier mass balance are also analyzed by the correlation approach, which is frequently used in geostatistics. The paper finds that there are different spatiotemporal variations over the glaciers in western China: (1) For a single glacier, the albedo varies gently with altitude on its tongue and increases fast in the middle part, while in the accumulation zones, the albedo value appears in the form of fluctuation. This could provide a quantitative method to retrieve the snowline by determining the threshold albedo value of snowpack and bare ice. (2) For the glaciers in western China, the albedo decreases with distance to the center of Tibetan Plateau (TP). This may relate to the elevation of glacier, for the speed of glacier retreat highly depends on air temperature. (3) In the summer period, albedo on most glaciers declines over the last 12 years, and it decreases much faster in southeastern TP than other regions, for which air temperature overwhelms the black carbon concentration. In addition, the trend of glacier albedo in summer is greatly correlated with that of measured glacier mass balance, which implies that the long‐term albedo datasets by remote sensing technology could be used to monitor and predict the change of glacier mass balance in the future. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

A rain on snow climatology and temporal analysis for the eastern United States     

Lori J. Wachowicz  Thomas L. Mote  Gina R. Henderson 《自然地理学》2020,41(1):54-69

ABSTRACT

Rain-on-snow (ROS) has the potential to produce devastating floods by enhancing runoff from snowmelt. Although a common phenomenon across the eastern United States, little research has focused on ROS in this region. This study used a gridded observational snow dataset from 1960–2009 to establish a comprehensive seasonal climatology of ROS for this region. Additionally, different rain and snow thresholds were compared while considering temporal trends in ROS occurrence at four grid cells representing individual locations. Results show most ROS events occur in MAM (March-April-May). ROS events identified with rainfall >1 cm are more frequent near the east coast and events identified with >1 cm snow loss are more common in higher latitudes and/or elevations. Decreasing trends in DJF (December-January-February) ROS events were identified near the coastal areas, with increasing trends in the northern portion of the domain. Significant decreasing trends in MAM ROS are likewise present on a regional scale. Factors playing a role in snowpack depth and rainfall, such as movement of storm tracks in this region, should be considered with future work to discern mechanisms causing the changes in ROS frequency.  相似文献   

铁同位素分析测试技术研究进展   总被引：5，自引：3，他引：2  

秦燕  徐衍明  侯可军  李延河  陈蕾 《岩矿测试》2020,39(2):151-161

铁是地球上丰度最高的变价元素,在自然界大量分布于各类矿物、岩石、流体和生物体中,并广泛参与成岩作用、成矿作用、热液活动和生命活动过程。铁同位素组成对地球化学、天体化学和生物化学方面提供重要的信息,是同位素地球化学研究领域的热点。铁同位素的精确测量是开展相关研究的重要基础。本文评述了铁同位素测试技术的研究进展,主要包括:①溶液法测试铁同位素样品纯化过程中阴离子树脂的改进;②质谱分析从传统的热电离质谱法发展为多接收电感耦合等离子体质谱法;③激光微区原位测试技术的研发等。在此基础上,对测试过程中会导致产生铁同位素分馏的步骤和校正方法进行了总结,并对各种测试方法的优缺点进行了评述。本文认为:溶液法分析流程长且复杂,但分析精度高(0.03‰,2SD)、方法稳定;微区原位分析方法从纳秒激光剥蚀发展为飞秒激光剥蚀,脉冲持续时间更短、脉冲峰值强度更高(可达10~(12)W),聚焦强度超过10~(20)W/cm~2,使其具有分析速度快、空间分辨率高的优势。微区原位法可以从微观角度去讨论铁同位素变化的地球化学过程,但基体效应的存在限制了微区原位铁同位素的广泛应用。因此,缩短溶液法分析流程,开发系列基体匹配的标准样品,是铁同位素分析方法研发的方向。  相似文献