祁连山老虎沟12号冰川消融区不同天气条件下的能量收支特征     

张佳佳  孙维君  杜文涛  陈记祖  秦翔 《冰川冻土》2020,42(2):332-343

冰川表面能量平衡模型建立了冰川与大气之间的联系。为探讨不同天气条件对冰川能量收支的影响, 利用祁连山老虎沟12号冰川海拔4 550 m处的气象资料（2011年8月24日 - 9月6日）, 结合能量平衡模型, 分析了不同天气条件下的能量收支变化特征。结果表明： 受云量影响, 晴天条件下向下短波辐射（318.3 W·m^-2）是多云条件下的1.5倍, 是阴天条件下的3倍。三种天气条件下的向下长波辐射, 晴天（215.4 W·m^-2）<多云（267.4 W·m^-2）<阴天（291.6 W·m^-2）。受固态降水的影响, 阴天条件下冰川反照率（0.50）是晴天时的2倍多。而三种天气下的最大消融耗热, 晴天（739.6 W·m^-2）>多云（582.8 W·m^-2）>阴天（324.5 W·m^-2）。在能量收入项中, 净短波辐射是主要来源（98%）, 但是受天气条件影响, 能量支出各项所占比例有明显差异; 在三种天气条件下, 净长波辐射所占比例分别为35%、 31%和23%, 消融耗热所占比例分别为62%、 64%和75%, 潜热通量所占比例相差不大。  相似文献   

DNDC模型的研究进展及其在高寒生态系统的应用展望   总被引：1，自引：0，他引：1  

刘放  吴明辉  杨梅学  陈生云 《冰川冻土》2020,42(4):1321-1333

DNDC（Denitrification-Decomposition, 反硝化-分解）模型是建立在元素丰度、 耦合、 循环和动力四个概念之上的生物地球化学模型。作为将生物地球化学理论应用于当前生态环境问题的桥梁, DNDC模型通过计算反硝化和有机质分解来模拟生态系统中碳氮循环过程, 其最终目的是计算目标生态系统中不同库间的温室气体排放通量。经过二十多年的发展, DNDC模型已成为目前国际上最成功的生物地球化学模型之一。文章阐述了DNDC模型的发展历程、 科学结构、 模型验证及校正, 总结了DNDC模型在生态系统应用中的主要研究进展及不足之处, 并对DNDC模型在高寒生态系统中的应用提出展望。  相似文献   

中国第一代再分析产品CRA Interim气温在东南极中山站 - Dome A断面的适用性分析     

朱江萍  谢爱红  丁明虎  赵聪  郭晓寅  胡婉嫔  徐冰  秦翔 《冰川冻土》2020,42(4):1145-1157

2017年中国气象局发布中国第一代全球大气和陆面再分析产品（以下简称“中国再分析产品”）CRA Interim, 通过对比CRA Interim气温资料与中国在南极考察区域中山站 - Dome A断面气象站实测2 m气温、 欧洲中期数值预报中心再分析产品（以下简称“欧洲再分析产品”）ERA Interim和ERA5相应的气温资料, 分析了CRA Interim气温在东南极中山站 - Dome A断面的适用性。结果表明： 三种再分析产品均能反映研究区域的气温变化, 均具有一定适用性, 但是都存在一定偏差且适用性存在区域差异和季节差异。CRA Interim、 ERA Interim、 ERA5对中山站 - Dome A断面气温的解释方差分别为81.3%、 87.1%、 87.2%。中国与欧洲再分析产品对日均值与最低温的反演都呈现负偏差, CRA Interim对最高温的反演表现为负偏差（-1.8 ℃）, 欧洲再分析产品则表现为正偏差（ERA Interim和ERA5偏差分别为0.5 ℃和0.8 ℃）。中国与欧洲再分析产品在位于冰盖边缘的中山站适用性最好, 位于冰盖内陆的Dome A次之, 对Eagle站气温的反演偏差较大。三种再分析产品对冬季气温反演最差, ERA Interim对秋季气温反演最好, CRA Interim和ERA5对夏季气温反演最好。CRA Interim、 ERA Interim、 ERA5对极端低温事件发生时最低温的解释方差分别为46.1%、 76.9%、 87.3%, 对极端高温事件发生时最高温的解释方差分别为59.9%、 65.1%、 73.6%, 极端事件发生时ERA5对极端气温的反演更为准确。2016年9月3日 - 13日极端低温事件主要受冷高压的影响, 7月25日 - 8月6日极端高温事件主要受暖低压和暖舌的影响。CRA Interim能够反演东南极中山站 - Dome A断面的气温及极端气温事件的变化, 但对风场尤其是中山站风场的反演不准确。与欧洲再分析产品相比, CRA Interim在中山站 - Dome A断面的适用性较低, 三种再分析产品中ERA5更适于南极极端天气与气候的研究。  相似文献   

无人机在冰川复杂地形监测中的应用   总被引：1，自引：1，他引：0  

车彦军  王世金  刘婧 《冰川冻土》2020,42(4):1391-1399

冰川作为冰冻圈核心要素之一, 是气候变化的天然指示器。通过监测冰川变化, 可以了解局地或全球气候波动, 无人机飞行测量技术是当代冰川观测研究的重要监测技术。选取玉龙雪山白水河1号冰川为研究区, 利用无人机低空飞行航测, 获取冰川末端分辨率为0.09 m的正射影像和数字地表模型（DSM）。将正射影像与高分一号影像、 Google Earth提供的Pléiade影像进行对比分析, 结果表明： 空间上, 无人机航测正射影像能较好的与高分一号、 Pléiade影像产品进行匹配。高分辨率无人机航测影像, 能够很好地表达冰面地形和一些微地貌特征。同时, 无人机航测构建的空间分辨率为0.09 m的DSM模型, 对冰面地形特征反映地更为详尽和准确。此外, 本次航测结合历年卫星遥感数据和地形图资料表明： 自1957年至2018年5月, 白水河1号冰川末端平面距离累积退缩达（646.27±12.04） m。无人机技术在复杂地形、 多云天气、 人工观测难的冰川环境中开展摄影测量具有很大应用前景。通过冰川末端无人机航测实地验证, 将为下一步整条冰川物质平衡的监测和计算提供技术和方法支撑。  相似文献   

新疆山地冰川变化及影响研究进展          下载免费PDF全文

徐丽萍  李鹏辉  李忠勤  张正勇  王璞玉  徐春海 《水科学进展》2020,31(6):946-959

揭示新疆山地冰川变化及其影响,对新疆山地-绿洲-荒漠系统的健康和稳定发展意义重大。系统梳理新疆冰川物理变化、化学过程、生物资源、气候响应与生态效应等研究成果。结果表明:①新疆山地冰川总体上呈加速消融之势,且受地形、气候影响,冰川变化的区域性差异明显;②气溶胶解释了乌鲁木齐河源1号冰川表层物质的组成与来源,同位素定量了各流域径流中冰川融水的比例;③冰川变化对极端微生物生存条件、空间分布的影响研究较为成熟,但其与生物资源间的综合反馈机理尚不明晰;④冰川消融对水资源的影响随冰川融水拐点的到来而加剧,造成的生态服务缩减和冰雪产业损失日益凸显。制定统一的冰川提取标准、扩宽研究视角、全面系统观测冰川、提高模拟预测精度、加强灾害预警与制定对策是未来新疆山地冰川研究的关注点。  相似文献   

SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year (2007–2009)     

Jérôme Korona  Etienne Berthier  Marc Bernard  Frédérique Rémy  Eric Thouvenot 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(2):204-212

Monitoring the evolution of polar glaciers, ice caps and ice streams is of utmost importance because they constitute a good indicator of global climate change and contribute significantly to ongoing sea level rise. Accurate topographic surveys are particularly relevant as they reflect the geometric evolution of ice masses. Unfortunately, the precision and/or spatial coverage of current satellite missions (radar altimetry, ICESat) or field surveys are generally insufficient. Improving our knowledge of the topography of Polar Regions is the goal of the SPIRIT (SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies) international polar year (IPY) project. SPIRIT will allow (1) the acquisition of a large archive of SPOT 5 stereoscopic images covering most polar ice masses and, (2) the delivery of digital terrain models (DTM) to the scientific community.Here, we present the architecture of this project and the coverage achieved over northern and southern polar areas during the first year of IPY (July 2007 to April 2008). We also provide the first accuracy assessments of the SPIRIT DTMs. Over Jakobshavn Isbrae (West Greenland), SPIRIT elevations are within ±6 m of ICESat elevations for 90% of the data. Some comparisons with ICESat profiles over Devon ice cap (Canada), St Elias Mountains (Alaska) and west Svalbard confirm the good overall quality of the SPIRIT DTMs although large errors are observed in the flat accumulation area of Devon ice cap. We then demonstrate the potential of SPIRIT DTMs for mapping glacier elevation changes. The comparison of summer-2007 SPIRIT DTMs with October-2003 ICESat profiles shows that the thinning of Jakobshavn Isbrae (by 30–40 m in 4 years) is restricted to the fast glacier trunk. The thinning of the coastal part of the ice stream (by over 100 m) and the retreat of its calving front (by up to 10 km) are clearly depicted by comparing the SPIRIT DTM to an ASTER April-2003 DTM.  相似文献   

Glacier Extent and Volume Change （1966-9000） on the Su-lo Mountain in Northeastern Tibetan Plateau,China   总被引：2，自引：2，他引：0  

WANG Yetang  ;HOU Shugui  ;HONG Sungmin  ;HUR Soon Do  ;LIU Yaping 《山地科学学报》2008,5(4):299-309

The topographic maps of 1：50, 000 scales, aerial photographs taken in 1966, one Landsat image taken in 1999, and SRTM data from 2000 were used to quantify the losses in area and volume of the glaciers on the Su-lo Mountain, in the northeastern Tibetan Plateau, China in the past 30 years. The total glacier area decreased from 492.9 km^2 in 1966 to 458.2 km^2 in 1999. The volume loss of the studied glaciers reached 1.4 km^3 from 1966 to 2000. This agrees with documented changes in other mountain glaciers of the whole Tibetan Plateau.  相似文献   

Granites of western Karakorum and northern Kohistan (Pakistan): A composite mid-cretaceous to upper cenozoic magmatism     

《Lithos》1987,20(1):19-40

The petrography, the chemical-mineralogical typology and the ages of six plutonic units, four from the Karakorum axial batholith (Darkot Pass, Ghamu Bar, Batura and Hunza units) and two of northern Kohistan (Gindai and Nomal plutons) are defined and compared based on field data and analyses of up to 78 samples (major elements, REE, Rb-S.sbnd;Sr and KAr isotopes). The Karakorum axial batholith is a composite body. Three major intrusive stages occurred: (1) around Mid-Cretaceous times (ca. 110-95 Ma) with the emplacement of subalkaline, i.e. monzonitic (Darkot Pass) and calc-alkaline (Hunza, ?Ghamu Bar) units; (2) during Palaeogene, maybe up to 43 Ma (Batura subalkaline unit). A strong tectonommetamorphic event, recorded in the gneissification of the Cretaceous intrusives, occurred between these two stages; it may be of Palaeocene age. P-T estimates of the highest metamorphic grade rocks of the Hunza unit have yielded values of 580–640°C and 5 ± 0.5 kbar; and (3) during Upper Miocene (ca. 9 Ma; Baltoro subalkaline unit; Debon et al., 1986c). In addition, a conspicuous network of aplo-pegmatitic dykes emplaced into the Hunza area, possibly from the Eocene up to the Upper Cenozoic with a maximum during the Middle Miocene (ca. 15 Ma). Most of these major magmatic stages are met again among the acidic intrusives and dykes of northern Kohistan: the first one as blastomylonitic tholeiitic plutons (Nomal; ca. 102 Ma; Petterson and Windley, 1985), the second one as subalkaline plutons (Gindai; ca. 59 Ma), and a third one as leucocratic dykes, of Oligocene age (ca. 30 Ma; Petterson and Windley, 1985).These data may be related to the geodynamic evolution of the NW part of the India-Eurasia suture zone, thus allowing better constraints on the major steps of this evolution. The partly synchronous closures, by N-dipping subduction, of the two Tethys branches which are assumed to have encircled the Kohistan arc in Upper Mesozoic times, may have generated both the Karakorum and the Kohistan intrusives of Cretaceous and Palaeogene ages. The northern branch very likely closed before the southern one. At the time of the second intrusive stage (Palaeogene): (a) Kohistan and Karakorum had already collided, were welded and had suffered the same major tectonometamorphic event; (b) subduction of the southern Tethys floor beneath the welded Kohistan-Karakorum was still active; (c) however, collision between India and Kohistan-Karakorum may have already begun, particularly at the level of the Nanga Parbat promontory. Finally, it is emphasized that the intrusive processes continued in the Karakorum long after the collision (e.g., Baltoro granite).  相似文献   

全球冰川径流中硅的研究进展     

刘莎  李向应  杨船洋  韩添丁  井哲帆  朱永华 《冰川冻土》2021,43(2):390-404

硅(Si)是硅藻等海洋生物必需的营养元素,在海洋生态系统和碳循环方面扮演着重要角色.在全球变暖背景下,冰川加速消融,融水径流量快速增加,流域硅酸盐风化作用逐渐增强,导致大量Si元素随着融水释放出来并进入下游,很可能影响陆地与海洋生态系统生产力、碳循环并反馈气候变化.当前与冰川消融有关的Si释放及其影响研究已成为国际热点...  相似文献   

High-precision measurements of the inter-annual evolution for Urumqi Glacier No.1 in eastern Tien Shan,China     

ChunHai Xu  ZhongQin Li  JianXin Mu  PuYu Wang  FeiTeng Wang 《寒旱区科学》2021,13(6):474-487

High-precision measuring of glacier evolution remains a challenge as the available global and regional remote sensing techniques cannot satisfactorily capture the local-scale processes of most small- and medium-sized mountain glaciers. In this study, we use a high-precision local remote sensing technique, long-range terrestrial laser scanning (TLS), to measure the evolution of Urumqi Glacier No.1 at an annual scale. We found that the dense point clouds derived from the TLS survey can be used to reconstruct glacier surface terrain, with certain details, such as depressions, debris-covered areas, and supra-glacial drainages can be distinguished. The glacier experienced pronounced thickness thinning and continuous retreat over the last four mass-balance years (2015-2019). The mean surface slope of Urumqi Glacier No.1 gradually steepened, which may increase the removal of glacier mass. The glacier was deeply incised by two very prominent primary supra-glacial rivers, and those rivers presented a widening trend. Extensive networks of supra-glacial channels had a significant impact on accelerated glacier mass loss. High-precision measuring is of vital importance to understanding the annual evolution of this type of glacier.  相似文献