天山积雪初步研究

本文依据气象、野外调查和部分文献资料写成,着重分析了天山最大积雪深度、积雪初、终期及其积雪期特征。研究表明,天山积雪存在明显地域差异:中天山和南天山南坡部分山区最大雪深超过100cm,甚至达到200或300cm,而东天山南坡盆地雪深仅15cm。中山带及其以下地区最大雪深出现在冬季始末,而高山带在暖季。林区雪深随海拔而增加,并在林线附近达到最大,然后急剧减小。天山中段北坡海拔440—3500m之间,每上升100m,积雪期延长80天;南坡小于此值。     

天山地区影响稳定积雪形成的初始气候条件研究：以天山积雪雪崩研究…

本文利用天山积雪雪崩研究站的历史资料分析了影响稳定积雪形成的初始气候条件，对降雪量的月间分布、降雪及气温与地温对稳定积雪的影响进行了阐述。     

天山北坡中段气候垂直分异研究

在分析天山北坡中段气候要素垂直分布显著差异基础上，采用热量和水分指标，并参照植被和土壤的垂直分布差异，将天山北坡中段划分出（１）前山冲积扇，冲积平原温带。（２）中低山寒温带，（３）亚高山－高山寒带（４）高山冰雪带等四个垂直气候带，为认识本地区山地气候资源，充分开发与利用山地气候资源潜力，提供了必要的参考依据。     

中国天山西部季节性森林积雪物理特性

积雪特殊的物理特性对冰雪水文过程、积雪生态系统、不同尺度的气候系统有重要影响。目前对林下积雪物理特性缺乏系统性研究,因此对天山雪岭云杉林下季节性积雪深度、沉降速率、密度和含水率进行观测分析。结果表明：林下积雪深度小于开阔地;林下积雪沉降速率和新雪密实化率小于开阔地,且稳定期沉降速率小于融雪期。稳定期林下积雪密度小于开阔地,林下雪层密度最大值位于中粒雪层,开阔地则位于粗粒雪层;融雪期则全层密度趋于一致。稳定期林下雪层含水率随深度递减,开阔地雪层最大值出现粗粒雪层;融雪期雪层汗水峰值出现在细粒雪层,新雪层最小,林下雪层由细粒雪层到深霜层始终呈减小趋势,开阔地雪层由细粒雪层至中粒雪层逐渐减小,粗粒雪层至深霜层逐渐增大;稳定期雪层含水率日变化随深度的递减逐渐减小,开阔地大于林下;开阔地的新雪层和细粒雪层含水率的日变化大于林下,粗粒雪层到深霜层则小于林下。     

中国天山积雪雪崩站区的地理环境

中国天山积雪雪崩站站区自然地理垂直地带完整。降水丰富，最大达１１４０．８ｍｍ。冬半年降雪量占年降水量的３０％左右。积雪深度多年平均８０ｃｍ。深厚的积雪使站区每年冬季都发生雪崩和风吹雪灾害，成为天山大陆性雪崩研究的天然场所。同时，站区生态与环境良好，植被、土壤种类集天山之大成。站区旅游资源引人入胜。北有“东方阿尔卑斯”之称的乔尔马；南有巴音布鲁克天鹅湖，均由天山公路与本站相连通。     

中国天山西部山地积雪辐射的若干特征

文中讨论了天山西部山地积雪辐射的若干物理参量及其光学特点,根据所测资料,对各种规律曲线和现象也给出了理论上阐述和说明。尤其文中提到,在积雪的长波辐射变化中,冬季呈凸型线,春季呈凹型线,笔者称前者为正常型,后者为反常型,认为就该地区的山地特点而论,此结论是有说服力的。     

天山巩乃斯河谷融雪期积雪物质平衡初步研究

本文利用１９９４年３月中，下旬在中间科学院天山积雪雪崩研究站（以下简称积雪站）野外观测到的部分资料，对融雪期季节性积雪的物质平衡进行初步分析，同时利用物质平衡方程对积雪日融出量进行计算。     

天山地区影响稳定积雪形成的初始气候条件研究──以天山积雪雪崩研究站为例

本文利用天山积雪雪崩研究站的历史资料分析了影响稳定积雪形成的初始气候条件，对降雪量的月间分布、降雪及气温与地温对稳定积雪的影响进行了阐述。     

中国天山西部季节性森林积雪雪层温度时空分布特征

利用2009年12月27日～2010年4月2日天山积雪站站区内开阔地和雪岭云杉(Picea schrenkiana)林下6次降雪过程后雪层内时间间隔10 min的温度数据,探讨雪层温度变化特征。结果表明,越接近地表雪层温度越高,且在雪层表面形成冷中心和(局部)暖中心;在积雪稳定期林下雪层温度高于开阔地,融雪期林下低于开阔地;林下雪层冷、暖中心出现时间晚于开阔地,其强度也小于开阔地。林下雪层温度振幅小于开阔地,林下温度振幅拐点以上雪层温度振幅随深度和时间的递减率小于开阔地,拐点以下无明显差异。初冬,林下和开阔地雪层均为较小的正温度梯度,随着气温急剧下降,温度梯度逐渐增大,且从雪表向雪底递减,林下雪层负温度梯度出现时间晚于开阔地。开阔地和林下积雪表层正温度梯度最大值分别达到0.95℃/cm和0.82℃/cm,负温度梯度大值分别达到-0.84℃/cm和-0.35℃/cm;但开阔地全雪层日平均温度梯度小于林下雪层。     

天山西部山地冬季积雪能量交换特征分析

本文研究了天山西部冬季积雪的能量交换特征，分析了在严寒的冬季积雪总辐射，反射，长波辐射的日变化及积雪内部的能量收支和传递过程，研究表明，积雪总辐射，反射辐射由于受太阳高度角的影响具有明显的日变化，积雪层与大气交界处的热流交换最为剧烈，０．４ｍ以下雪层热流交换已不受外界大气环境影响，而是保持着几乎固定的数值。     

Vertical distribution of snow cover and its relation to temperature over the Manasi River Basin of Tianshan Mountains,Northwest China

How snow cover changes in response to climate change at different elevations within a mountainous basin is a less investigated question. In this study we focused on the vertical distribution of snow cover and its relation to elevation and temperature within different elevation zones of distinct climatology, taking the mountainous Manasi River Basin of Xinjiang, Northwest China as a case study. Data sources include MODIS 8-day snow product, MODIS land surface temperature (LST) data from 2001 to 2014, and in situ temperature data observed at three hydrological stations from 2001 to 2012. The results show that: (1) the vertical distribution of snow areal extent (SAE) is sensitive to elevation in low (<2100 m) and high altitude (>3200 m) regions and shows four different seasonal patterns, each pattern is well correspondent to the variation of temperature. (2) The correlation between vertical changes of the SAE and temperature is significant in all seasons except for winter. (3) The correlation between annual changes of the SAE and temperature decreases with increasing elevation, the negative correlation is significant in area below 4000 m. (4) The snow cover days (SCDs) and its long-term change show visible differences in different altitude range. (5) The long-term increasing trend of SCDs and decreasing trend of winter temperature have a strong vertical relation with elevation below 3600 m. The decreasing trend of SCDs is attributed to the increasing trend of summer temperature in the area above 3600 m.     

Sub-regional snow cover distribution across the southern Appalachian Mountains

Abstract

Snowfall in the Southern Appalachian Mountain region of the eastern US is characterized by much spatiotemporal variability. Annual snowfall totals vary by up to 75 cm, and variations in snowfall intensity can lead to large differences in the local snowfall distribution. Research has shown that the synoptic pattern associated with the snowfall strongly influences the regional-scale distribution of snow cover. However, topographic variability results in locally complex snow cover patterns that are not well understood or documented. In this study, we characterize the snow covered area (SCA) and fractional snow cover associated with different synoptic patterns in 14 individual sub-regions. We analyze 63 snow events using Moderate-resolution Imaging Spectroradiometer standard snow cover products to ascertain both qualitative and quantitative differences in snow cover across sub-regions. Among sub-regions, there is significant variation in the snow cover pattern from individual synoptic classes. Furthermore, the percent SCA follows the regional snowfall climatology, and sub-regions with the highest elevations and northerly latitudes exhibit the greatest variability. Results of the sub-regional analysis provide valuable guidance to forecasters by contributing a deeper understanding of local snow cover patterns and their relationship to synoptic-scale circulation features.     

基于MODIS数据中国天山积雪面积时空变化特征分析

基于2011-2015年MOD10A2积雪产品和气象数据,通过几何校正、去云预处理,应用归一化差分积雪指数算法等获取中国境内天山山区积雪覆盖面积数据,分析了积雪面积的时空变化特征及与气温降水的关系。结果表明：（1）年内积雪面积呈单峰变化,9月开始积累,次年1月达峰值,3月气温回暖消融加速,至7月最小。春秋季波动较大但没有明显的增减趋势,夏季积雪面积最小,冬季最大且呈减小趋势。（2）2001-2015年积雪覆盖面积整体上呈减少趋势,积雪覆盖率最大值的波动比最小值的波动更加剧烈。（3）积雪覆盖率随着海拔升高而增大,海拔<1 500 m区域积雪覆盖率低于10%,海拔>4 500 m以上区域平均可达70%,为常年稳定积雪区。积雪覆盖率在西北坡最高,南坡最低。（4）年均气温升高是积雪覆盖面积减小的主因,年积雪覆盖面积变化与年降水量变化保持一致的下降趋势。     

天山北坡土地利用/覆被及生态系统服务功能变化

土地利用/覆被变化及其生态效应是生态环境演变最重要的因素之一,其研究对于促进区域生态经济协调发展有重要意义。以天山北坡土地利用/覆被数据为基础,分析了土地利用/覆被与生态系统服务功能的时空特征及其差异。结果表明:1989年到2000年研究区草地、未利用土地面积明显减少,其它类型土地面积在增加,奇台县土地利用变化动态度最高,乌鲁木齐最低;区域生态系统服务功能从1989年的31 993.31×106元增加到2000年的32 126.27×106元,增加量为132.96×106元,增长率为0.42%,其中,增长最多的是奇台县,下降最大的是玛纳斯县;山前倾斜平原圈是土地利用/覆被变化与生态系统服务功能价值变化的集中区域。天山北坡生态系统服务价值没有降低不能说明生态环境得到了良好的维护与保育,将来区域发展必须加强生态环境保护力度。     

表层雪中稳定同位素季节变化及其与水汽输送的关系——以天山乌鲁木齐河源1号冰川积累区为例

根据2002年9月至2005年12月在天山乌鲁木齐河源1号冰川积累区采集的表层雪样品,揭示了该区表层雪中δ<'18>O值的季节变化特征,讨论了水汽输送对降水中δ<'18>O值变化的影响.研究表明,天山乌鲁木齐河源1号冰川表层雪中δ<'18>O值季节变化显著,变幅可达12.59‰左右,其变化趋势和气温的变化趋势基本一致,...     

1960年以来中国天山冰川面积及气候变化

Based on the statistics of glacier area variation measured in the Chinese Tianshan Mountains since 1960,the response of glacier area variation to climate change is discussed systematically.As a result,the total area of the glaciers has been reduced by 11.5% in the past 50 years,which is a weighted percentage according to the glacier area variations of 10 drainage basins separated by the Glacier Inventory of China (GIC).The annual percentage of area changes (APAC) of glaciers in the Chinese Tianshan Mountains is 0.31% after the standardization of the study period.The APAC varies widely for different drainage basins,but the glaciers are in a state of rapid retreat,generally.According to the 14 meteorological sta-tions in the Chinese Tianshan Mountains,both the temperature and precipitation display a marked increasing tendency from 1960 to 2009 at a rate of 0.34℃·(10a)-1 and 11 mm·(10a) -1,respectively.The temperature in the dry seasons (from November to March) increases rapidly at a rate of 0.46℃·(10a)-1,but the precipitation grows slowly at 2.3 mm·(10a)-1.While the temperature in the wet seasons (from April to October) grows at a rate of 0.25℃·(10a)-1,but the precipitation increases at 8.7 mm·(10a)-1.The annual and seasonal climatic trends ac-celerate the retreat of glaciers.     

中国天山冰川变化脆弱性研究

冰川是重要的淡水资源,对社会经济发展和生态环境影响显著,而其变化的脆弱性也关乎区域生态服务和经济可持续发展。本文以中国天山为例,基于脆弱性的暴露度、敏感性、适应能力构建涵盖自然地理特征、人口状况、社会经济水平、农业发展和社会服务等因素的冰川变化脆弱性框架,并以此针对性构建评价指标体系,探析天山冰川变化脆弱性的空间特征,采用地理探测器模型探讨自然、社会、经济和人口等因素对冰川变化适应能力的影响及交互作用。结果表明：① 脆弱性等级由西部地区向东部地区呈降低趋势,且水平差异显著。天山东部地区脆弱性最低、中部地区次之、西部地区较高。② 暴露度、敏感性和适应能力在空间上分别存在明显正相关与负相关,表明区域范围内冰川变化具有高暴露、高敏感地区往往适应能力较低,进而导致脆弱性较高;反之,脆弱性较低。③ 天山应对冰川变化能力的空间异质性是自然、社会、经济和人口因素共同作用的结果。其中,第二、三产业产值、城镇人口数、城镇固定资产投资与年末单位从业人员等因素具有主导作用。     

Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains, northeastern China

Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the western flank of the Da Xing'anling(Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration(generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7–8.2 °C higher than the mean annual air temperatures recorded at the Gen'he Weather Station. The beginning date for stable snow cover establishment(SE date) and the initial snow depth(SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.     

天山东段冰雪消融与产汇流水文过程——以乌鲁木齐河源区为例

应用天山北坡乌鲁木齐河源区1 号冰川、空冰斗和总控3 个水文断面2011 年5-9 月每10min 实测水位数据、15 min 的气温、降水数据、1 号冰川消融及空冰斗区积雪观测数据,采用排除和不排除降水对冰雪消融产流影响的研究方法,系统分析了不同冰川覆盖率下水文断面冰雪消融特征及产汇流过程。结果表明：（1） 乌鲁木齐河源区3 个水文断面流量昼夜差异明显,1 号冰川水文断面白天径流大于夜晚径流,空冰斗和总控断面则相反;3 个断面流量亦具有显著日变化过程,且流量峰值大小和到来的时间存在差异。（2） 在排除与不排除降水两种天气影响下,1 号冰川最大流量滞后最高气温分别为1~3 h 和0~1 h;空冰斗断面分别为10~16 h和13 h,总控断面分别为5~11 h 和6~7 h,反映了1 号冰川从消融产流到汇流时间最短,空冰斗积雪消融产流时间最长,总控位于二者之间,同时亦反映伴随降水过程冰雪融水汇流迅速,即从产流到汇流时间有一定的缩短。（3） 影响3 个水文断面流量变化的因素不同,冰川区热量条件是影响1 号冰川水文断面的关键,1 号冰川在过去20 余年间,冰内、冰下排水道变得更为单一,对融水的阻滞和贮存作用弱化,融水汇流过程变得更为迅速。（4） 冰川覆盖山区流域水文断面在冰川消融期的流量过程线变化及最大流量与最高气温时滞变化规律在一定程度上对于认识冰川覆盖率有差异背景下的流域下垫面水系演化、冰雪消融过程及水文断面径流补给具有重要的指示意义。