极地冰雪氢氧同位素指标及其指示意义

本文综述了水汽来源状况、降水季节变化、火山喷发、太阳活动等气候环境因素对极地冰雪中同位素含量的可能影响及其程度 ,以及降水区域不均衡性、降水年际不均衡性、逆温层和同位素在冰雪中的扩散迁移作用等几种不稳定因素可能对冰雪同位素分析造成的干扰 ;在此基础上 ,综述了极地冰雪中δ1 8O、δD和其差值d(d =δD - 8δ1 8O)与局部或全球气温之间的一些线性关系 (包括全球尺度 ,格陵兰地区 ,南极地区等 )及它们在空间分布上的变化规律     

Variation of Stable Isotopes in Surface Snow along a Traverse from Coast to Plateau’s interior in East Antarctica and Its Climatic Significance

The variations of stable water isotopes of surface snow in east Antarctic Ice Sheet, are discussed by a total of 251 samples, which were taken along a 330 km traverse from Zhongshan Station to the outer edge of the Antarctic plateau and from four snow pits excavated along the route. Analyzing results of the samples showed the expected linear relationship between the parameters ?D and ?18O with slope S1 and intercept d1. When the data set was examined using a sliding window with a width of 5 samples, it was found that there were two areas with different ratios of S1 and d1. The boundary between these two areas occurred at an elevation of about 2,000 m, suggesting two different sources of water vapour. Nearly half (47%) of the fresh-snow samples had negative deuterium excess (d=?D? 8?18O) values, but few of the snow pit samples did, suggesting that variations of ? are quickly smoothed by isotopic diffusion in the near-surface firn. Analysis of the phase relationship between ?D and deuterium excess in the snow pit stratigraphies showed that they were mostly in phase from Jan. 1994 to Sept. 1995, but mostly out of phase from Sept. 1995 to Jan. 1997.     

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,...     

Comparisons of stable isotopic fractionation in winter and summer at Baishui Glacier No. 1, Mt. Yulong, China

Based on the data of δ18O in surface snow, snow pits, meltwater and the glacier-fed river water at Baishui Glacier No.1, Mt. Yulong, the isotopic fractionation behaviors in the typical monsoonal temperate glacier system in winter and summer were compared. The results indicate that the isotopic fractionation degree in summer is greater than that in winter, suggesting that the snow/ice melting is more intense in summer. Moreover, whenever it is in winter or summer, from surface snow to meltwater, and to glacier-fed river water, the gradient of δ18O with altitude gradually increases. This shows that the degree of isotopic fractionation gradually strengthens when surface snow is being converted into meltwater and finally into glacial river water, which suggests that the influence of post-depositional processes on δ18O gradient in the monsoonal temperate glacier region differs spatially.     

玉龙雪山冰川稳定同位素分馏冬夏对比

利用玉龙雪山白水1号冰川区冬季和夏季表面积雪、雪坑、融水以及白水河河水中δ¹⁸O资料,对比分析了冬季和夏季我国典型季风温冰川系统内稳定同位素分馏行为的差异。分析结果表明,夏季冰川系统内各水体相变过程中稳定同位素分馏程度均比冬季强烈,指示出夏季季风海洋型冰川强烈消融的特点。另外,不论是冬季还是夏季,从表面积雪到融水再到由融水补给的河流,δ¹⁸O垂直变化梯度依次增大,反映了从固态降雪向冰川融水补给的河流河水转换过程中,稳定同位素分馏程度逐渐增强,体现了沉积后过程对海洋型冰川区同位素记录的影响具有空间差异性。     

Seasonal variations in heavy metals concentrations in Mt. Qomolangma Region snow

The concentrations of heavy metals Ba, Pb, Cu, Zn and Co in snow pit collected in September, 2005 from the accumulation area of the East Rongbuk Glacier (6523 m a.s.l.), which lies on the northern slope of Mt. Qomolangma, were determined by inductively coupled plasma mass spectrometry (ICP-MS). Concentrations (pg/ml) of heavy metals are Ba2-227, Co2.8-15.7, Cu10-120, Zn29-4948 and Pb14-142, respectively. The δ18O was determined by MAT-252. The time period of the snow pit spans from autumn 2005 to summer 2004. Seasonal variations of the concentrations and δ18O are observed, of which Pb, Cu, Zn and Co are much lower in summer monsoon season than that in non summer monsoon season, suggesting that different sources of heavy metals contributed to the site. EFc (crustal enrichment factors) is Co3.6, Cu27, Pb33 and Zn180, respectively. Higher EFc values of Pb, Cu and Zn suggest that Pb, Cu especially Zn are mainly contributed by anthropogenic sources.     

玉龙雪山冰川稳定同位素分馏冬夏对比

1 Introduction Under the dominance of South Asian monsoon, China’s temperate glaciers are distributed on Hengduan Mountains (southeast of Tibetan Plateau), the central part and southern slope of the Himalaya Mountains as well as the central and eastern p…     

Distribution features of stable oxygen isotopes in the typical monsoon temperate-glacier region, Mountain Yulong in China

During the summers of 1999 and 2000, sampling was carried out in Mt. Yulong, for the investigation of the spatial distribution of oxygen stable isotope in the atmospheric glacial hydro system and similar results obtained in the two years have confirmed our conclusion. There is an evident negative correlation between stable isotopic composition and air temperature precipitation amount, suggesting that there exits a strong "precipitation amount effect" in this typical monsoon temperate glacier region. There are marked differences between the δ 18 O values in winter accumulated snow, glacial meltwater, summer precipitation and glacier feeding stream. Under the control of varied climatic conditions, spatial and temporal variations of above glacial hydro mediums are apparent. Isotopic depletion or fractionation and ionic changes had occurred during the phase change and transformation processes of snow ice, ice meltwater, flowing of runoff and contact with bedrock. The variation of stable isotope in a runoff can reflect not only its own flowing process but also its different feeding sources.     

珠穆朗玛峰地区雪冰中重金属浓度与季节变化

对2005 年9 月采自珠穆朗玛峰北坡海拔6523 m 的东绒布冰川积累区一批雪坑样品中重金属Ba, Co, Cu, Zn 和Pb 的浓度利用电感耦合等离子体质谱仪进行了测试, 重金属浓度范围分别为(pg/ml); Ba2~227、Co2.8~15.7、Cu 10~120、Zn29~4948、Pb14~142。并利用气体稳 定同位素质谱仪MAT-252 对样品稳定氧同位素比率(δ¹⁸O) 进行了测试, 雪坑样品对应的时间为2004 年夏到2005 年秋, δ¹⁸O和重金属元素的浓度都存在着季节变化特征。在夏季风期间δ¹⁸O 值和重金属元素的浓度都很低,而在非夏季风期间δ¹⁸O值和重金属元素浓度升高,反映了不同的水汽来源对重金属浓度季节变化的影响及其环境意义。Co, Cu, Pb, Zn 的地壳富集系数(EF_c) 分别为: 3.6、27、33、180, 表明该地区Pb, Cu, Zn 已经受到了人类活动的污染, 其中Zn 受到的污染最大。     

南极洲伊利莎白公主地区气候特征分析

通过对1996/1997年中国首次南极内陆冰盖考察地区——南极洲伊利莎白公主地区近300 km断面上70余个雪坑的δ¹⁸O和积累率资料的分析,首次揭示了本地区气候变化特征。即无论是气温还是降水都从沿海向内陆递减,但两者的变化又有差异,具体表现在气温从沿海向内陆持续递减,降水先递增后递减,表现出很强的地段性。同时探讨了二者变化的影响因素和影响机制。     

准噶尔盆地南缘荒漠区梭梭维持水源初步研究

为了了解沙漠植物梭梭维持水源的利用情况,探明其对水源的利用策略,利用稳定性同位素技术定位取样,对准噶尔盆地南缘荒漠区梭梭进行了研究.结果表明,冬季,梭梭基本没有直接利用降雪;随着融雪后浅层土壤含水率的上升,梭梭明显利用浅层土壤水;梭梭利用水源中,地下水占有很大比例,这种比例在冬季和夏季最高,最高幅度可达到80％,平均占到30％左右;降雨也是梭梭利用的水源之一,在降雨后的3～5 d内,梭梭木质部δ18O值有明显趋近降雨δ18O值的趋势.因此,本研究区的梭梭维持水源有多个途径,地下水、融雪形成的浅层土壤水是其主要水源,中、大量降雨也是其利用的水源之一.     

祁连山区季节性积雪资源的气候分析*

本文采用1986年10月至1988年9月NOAA—9、10两颗卫星的AVHRR资料标准化后反演的积雪参量,对照祈连山区26个气象站1951—1988年逐日雪深、雪密度和积雪日数的资科,修正卫星反演的平均值。得到高分辨率多年平均雪深和雪盖频率的空间分布。从而估算出各流域平均雪储量,并与降雪量和春季融雪径流作对此分析。     

Temporal and spatial variations of δ18O in precipitation of the Yarlung Zangbo River Basin

This paper reveals the temporal and spatial variations of stable isotope in precipita-tion of the Yarlung Zangbo River Basin based on the variations of δ18O in precipitation at four stations (Lhaze, Nugesha, Yangcun and Nuxia) in 2005. The results show that δ18O of pre-cipitation has distinct seasonal changes in the Yarlung Zangbo River Basin. The higher value of δ18O occurs in spring prior to monsoon precipitation, and the lower value occurs during monsoon precipitation. From the spatial variations, with the altitude-effect and rainout process during moisture transport along the Yarlung Zangbo River Valley, 18O of precipitation is gradually depleted. Thus, δ18O of precipitation decreases gradually from the downstream to the upstream, and the lapse rate of δ18O in precipitation is approximately 0.34‰/100m and 0.7‰/100km for the two reasons. During monsoon precipitation, spatial variation of δ18O in precipitation is dominated by the amount effect in the large scale synoptic condition.     

珠穆朗玛峰地区雪冰中重金属浓度与季节变化

The concentrations of heavy metals Ba, Pb, Cu, Zn and Co in snow pit collected in September, 2005 from the accumulation area of the East Rongbuk Glacier (6523 m a.s.l.), which lies on the northern slope of Mt. Qomolangma, were determined by inductively coupled plasma mass spectrometry (ICP-MS). Concentrations (pg/ml) of heavy metals are Ba2-227, Co2.8-15.7, Cu10-120, Zn29-4948 and Pb14-142, respectively. The δ¹⁸O was determined by MAT-252. The time period of the snow pit spans from autumn 2005 to summer 2004. Seasonal variations of the concentrations and δ¹⁸O are observed, of which Pb, Cu, Zn and Co are much lower in summer monsoon season than that in non summer monsoon season, suggesting that different sources of heavy metals contributed to the site. EF_c (crustal enrichment factors) is Co3.6, Cu27, Pb33 and Zn180, respectively. Higher EF_c values of Pb, Cu and Zn suggest that Pb, Cu especially Zn are mainly contributed by anthropogenic sources. Foundation: National Natural Science Foundation of China, No.40501014; No.40871058 Author: Duan Jianping (1981–), Ph.D. Candidate, specialized in climate and environmental change.     

雅鲁藏布江流域降水中δ18O 的时空变化

通过研究2005年西藏雅鲁藏布江流域拉孜、奴各沙、羊村和奴下4个站点降水中的δ18O变化,揭示了雅鲁藏布江流域降水中稳定同位素的时空变化规律.研究显示,雅鲁藏布江流域降水中δ18O季节变化明显,高值出现在季风降水之前的春季,而低值出现在季风降水季节,其间降水中δ18O具有明显的"降水量效应";从空间上看,降水中的δ18O从下游至上游递减,造成这种分布特征主要是由于"高程效应"以及水汽远距离输送导致其中的18O被贫化的结果.经计算表明,雅鲁藏布江流域降水中δ18O由于"高程效应"造成的递减率为0.34‰/100m,而水平方向上自东向西由于水汽远距离输送造成的递减率为0.7‰/100km.从季风期间大范围的降水过程来看,降水中δ18O的空间变化主要受"降水量效应"制约.     

雅鲁藏布江流域降水中氧稳定同位素的时空变化

This paper reveals the temporal and spatial variations of stable isotope in precipita-tion of the Yarlung Zangbo River Basin based on the variations of δ18O in precipitation at four stations (Lhaze,Nugesha,Yangcun and Nuxia) in 2005. The results show that δ18O of pre-cipitation has distinct seasonal changes in the Yarlung Zangbo River Basin. The higher value of δ18O occurs in spring prior to monsoon precipitation,and the lower value occurs during monsoon precipitation. From the spatial variations,with the altitude-effect and rainout process during moisture transport along the Yarlung Zangbo River Valley,18O of precipitation is gradually depleted. Thus,δ18O of precipitation decreases gradually from the downstream to the upstream,and the lapse rate of δ18O in precipitation is approximately 0.34‰/100m and 0.7‰/100km for the two reasons. During monsoon precipitation,spatial variation of δ18O in precipitation is dominated by the amount effect in the large scale synoptic condition.     

Physical properties and stratigraphy of surface snow in western Dronning Maud Land, Antarctica

Information about the spatial variations of snow properties and of annual accumulation on ice sheets is important if we are to understand the results obtained from ice cores, satellite remote sensing data and changes in climate patterns. The layer structure and spatial variations of physical properties of surface snow in western Dronning Maud Land were analysed during the austral summers 1999/2000, 2000/01 and 2003/04 in five different snow zones. The measurements were performed in shallow (1–2 m) snow pits along a transect extending 350 km from the seaward edge of the ice shelf to the polar plateau. These pits covered at least the last annual accumulation and ranged in elevation from near sea level to 2500 m a.s.l. The ع⁸O values and accumulation rates had a good linear correlation with the distance from the coast. The mean accumulation on the ice shelf was 312±28 mm water equivalent (w.e.); in the coastal region it was 215±43 mm w.e. and on the polar plateau it was 92±25 mm w.e. The mean annual conductivity and grain size values decreased exponentially with increasing distance from the ice edge, by 48%/100 km and 18%/100 km respectively. The mean grain size varied between 1.5 and 1.8 mm. Depth hoar layers were a common phenomenon, especially under thin ice crusts, and were associated with low dielectric constant values.     

Temporal and spatial variations of δ^18O in precipitation of the Yarlung Zangbo River Basin

This paper reveals the temporal and spatial variations of stable isotope in precipitation of the Yarlung Zangbo River Basin based on the variations of δ^18O in precipitation at four stations （Lhaze, Nugesha, Yangcun and Nuxia） in 2005. The results show that δ^18O of precipitation has distinct seasonal changes in the Yarlung Zangbo River Basin. The higher value of δ^18O occurs in spring prior to monsoon precipitation, and the lower value occurs during monsoon precipitation. From the spatial variations, with the altitude-effect and rainout process during moisture transport along the Yarlung Zangbo River Valley, δ^18O of precipitation is gradually depleted. Thus, δ^18O of precipitation decreases gradually from the downstream to the upstream, and the lapse rate of δ^18O in precipitation is approximately 0.34‰/100m and 0.7%J‰/100km for the two reasons. During monsoon precipitation, spatial variation of δ^18O in precipitation is dominated by the amount effect in the large scale synoptic condition.     

A preliminary study on oxygen isotope of ice cores of Collins Ice Cap,King George Island,Antarctica

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南极中山站-Dome A断面表层雪稳定同位素空间分布及环境影响因素分析

中山站-Dome A断面是表层雪稳定同位素组成分析的理想区域,沿线进行δ18O、δD和d的空间分布及环境影响因素研究对反映东南极地区的气候变化和物质来源具有关键意义。因而,本文基于线性回归及相关性分析方法,详细探究了断面上多种环境因素与表层雪稳定同位素分布的空间关系。结果表明,温度和地理因素与同位素比值之间有显著相关关系,且海拔是地理因素中的主要影响因素,随海拔上升表层雪的δ18O呈线性下降趋势。另外,通过断面上δ-T斜率与南极其他断面对比,发现斜率可能具有冰盖近岸和内陆地区较低的区域性特征,而造成这一现象的原因是水汽源区的改变和低温条件下水汽过饱和时的同位素动力分馏。最后,d的空间分布在沿海区域和内陆区域也有不同,推测主控因素分别是水汽源区条件和温度。