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基于无人机遥感技术的南极冰川表面冰坑监测 被引量:5
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作者 张宝钢 赵剑 +3 位作者 马驰 李腾 程晓 刘雷保 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2019年第1期19-24,共6页
冰坑(ice doline)是指冰川表面因塌陷所形成的特殊地貌,由于冰坑的规模通常较小,相关的高分辨率遥感数据十分匮乏,加之其形成具有突发性和偶然性,目前的研究尚不充分.已有的研究主要通过对冰坑形成后的表面特征分析得出,对形成前冰面的... 冰坑(ice doline)是指冰川表面因塌陷所形成的特殊地貌,由于冰坑的规模通常较小,相关的高分辨率遥感数据十分匮乏,加之其形成具有突发性和偶然性,目前的研究尚不充分.已有的研究主要通过对冰坑形成后的表面特征分析得出,对形成前冰面的应力应变状态尚缺乏有效观测数据支撑.在我国第33次南极考察期间,中山站至内陆出发基地的达尔克冰川表面发生了塌陷,形成了冰坑地貌.在达尔克冰川开展长时间序列的无人机遥感监测,获取了塌陷事件发生前后多期高分辨率无人机遥感数据.利用该数据处理得到的塌陷区高分辨率数字高程模型(DEM)和数字正射模型(DOM),分析了塌陷发生前后冰面地形变化和融池分布,发现此处冰坑地貌的形成与冰下径流、冰上的融水过程有重要关系. 展开更多
关键词 南极 达尔克冰川 极地无人机 冰坑 冰下湖
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Deposition of atmospheric pollutant and their chemical characterization in snow pit profile at Dokriani Glacier,Central Himalaya 被引量:2
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作者 Shipika SUNDRIYAL Tanuj SHUKLA +3 位作者 Lekhendra TRIPATHEE Dwarika Prashad DOBHAL Sameer Kumar TIWARI Uday BHAN 《Journal of Mountain Science》 SCIE CSCD 2018年第10期2236-2246,共11页
The uncertainty in assessing the numerous atmospheric pollutants transported via wind from arid and semi-arid regions is affecting the glacial ecosystem. In our study area due to the complexity of the system, a promin... The uncertainty in assessing the numerous atmospheric pollutants transported via wind from arid and semi-arid regions is affecting the glacial ecosystem. In our study area due to the complexity of the system, a prominent seasonal difference noticed among major ions(Ca^(2+), Mg^(2+), SO_4^(2-), and NO_3^-). There is a need for understanding the ions cycling as a whole and the directionality of the feedback loops in the system. Therefore, we provide an appraisal of our current hypothesis for seasonal difference in major ion concentration from snow samples for two corresponding years(2013 and 2015) at Dokriani Glacier. A systematic study of chemical compositionsin the shallow snow pit from Dokriani Glacier was undertaken for the pre-monsoon season to understand the cycling of major ions from atmosphere to solute acquisition process. The intimating connections of ions cycling in snow and its temporal behavior was observed and analyzed through various statistical tests. Among major ions, the SO_4^(2-)has the highest concentration among anions on an average considered as 14.21% in 2013 and 29.46% in 2015. On the other side Ca^(2+) is the dominant cation contributing 28.22% in 2013 and 15.3% in 2015 on average. The average ratio of Na+/Cl-was higher in 2013 whereas lower in 2015. The backward trajectory analysis suggests the possible sources of the ions transported from Central Asia through the Western Disturbance(WD) as a prominent source of winter precipitation mainly in the Central Himalaya. Ionicconcentration of Ca^(2+) in cations was highly dominated while in anion SO_4^(2-)played the major role. Factor analysis and correlation matrix suggested that, the precipitation chemistry is mostly influenced by anthropogenic, crustal, and sea salt sources over the studied region. The elemental cycling through ocean, atmosphere and biosphere opens up new ways to understand the geochemical processes operating at the glacierized catchments of the Himalaya. Moreover, increasing the field-based studies in the coming decades would also have the certain advantage in overcoming the conceptual and computational geochemical modelling difficulties. 展开更多
关键词 Western disturbance Central Himalaya Factor analysis Correlation analysis Snow Stratigraphy Atmospheric pollutants
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忘不了那碗面
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作者 王子杨 《小作家选刊(小学生版)》 2008年第9期27-27,共1页
这件事对于别人也许不算什么大事,但对于我来说,这确实是件"大事"。事情发生在去年的寒假前。那时正值冬天,天亮得晚,而我那天起得早了些,就早早地去上学。走出家门,抬头一看,天上还挂着几颗星星。
关键词 路灯 寒假 面条 星星 正值 中年妇女 发生 冰坑 烟雾 太阳
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