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1.
Chemical characteristics and environmental significance of fresh snow deposition on Urumqi Glacier No. 1 of Tianshan Mountains, China 总被引：2，自引：0，他引：2
Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ SO42- NH4+ NO3- Cl- Na+ Mg2+ K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains. 相似文献
2.
Shipika Sundriyal Tanuj Shukla Lekhendra Tripathee Dwarika Prashad Dobhal Sameer Kumar Tiwari Uday Bhan 《山地科学学报》2018,15(10):2236-2246
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. 相似文献
3.
Snow samples collected from a 50 m firn core and two snow pits along the route of the 1996/1997 Chinese First Antarctic Inland Traverse Expedition in Princess Elizabeth Land, East Antarctica, have been analyzed for chemical composition and oxygen isotope ratio. Analyzing the relationship between the concentration and flux of major ions and accumulation rate can draw the following conclusions. 1 ) The concentrations of major ions in the atmosphere in the study region is big enough so that the concentrations of the ions do not vary with snow accumulation rate, that is to say, the concentrations of major chemical species are independent of snow accumulation rate. 2) The results of analyzing the depositional styles of major chemical species suggest that wet deposition dominates the major ions flux. In addition, there is no apparent correlation between nssSO2-4 fluctuations and isotope profile. This would indicate the short-term climatic effect of volcanism is not evident in the region. 相似文献
4.
研究了矿物包裹体中液相样品的制备及其成分中氯离子的测定方法。实验证明以均二苯卡巴肼为络合剂,以硝酸汞为滴定液测定痕量氯离子结果理想,其结果对研究矿床形成过程中的物理化学环境具有一定意义。 相似文献
5.
QI Jianhua LI Xianguo FENG Lijuan ZHANG Manping 《中国海洋大学学报(英文版)》2006,5(1):85-90
Total suspended particulate （TSP） samples were collected at three sites along the coast of Qingdao, China, before and during a major dust storm in March, 2002. For comparison, PM10（particulate matter with aerodynamic diameters less than 10μm） samples were collected at one of the three sites. The morphological observation and compositional analysis of bulk and individual particles were performed by using scanning electron microscopy equipped with an energy dispersive X-ray system （SEM/EDX） for the TSP and PM10 samples. The results showed that the particles of different kinds of morphology had different elemental compositions, but the particles of similar morphology did not always have the same elemental composition for non-dust samples. The morphology and composition of non-dust particles were different at different sites. The fractal and spherical particles existed mainly in the coarse fraction for non-dust samples, while in the fine mode （〈 10μm） there were floccules formed by fine particles flocking together and containing crustal elements. Compared with the non-dust particles, the dust particles were more homogeneous in terms of morphology, particle size and composition. Particles with irregular shapes and well-distributed sizes dominated in the dust samples, containing crustal elements such as Mg, A1, Si, Ca, Fe, etc. The high sulfur content indicated that homogeneous and heterogeneous reactions took place on the surfaces of the dust particles in the specific environment of Qingdao. 相似文献
6.
Seasonal and Spatial Variability of Microparticles in Snowpits on the Tibetan Plateau, China 总被引：1，自引：0，他引：1
ZHANG Yulana c KANG Shichanga b ZHANG Qianggonga CONG Zhiyuana ZHANG Yongjuna GAO Tanguanga ca Laboratory of Tibetan Environment Changes L Surface Processes 《山地科学学报》2010,7(1):15-25
The work presents microparticle concentrations in snowpits from the East Rongbuk Glacier on Mt. Qomolangma (Everest) (ER) (28.02°N, 86.96°E, 6536 m a.s.l.), the Zhadang Glacier on Mt. Nyainqentanglha (NQ) (30.47°N, 90.65°E, 5800m a.s.l.), and the Guoqu Glacier on Mt. Geladaindong (GL) (33.95°N, 91.28°E, 5823m a.s.l.) over the Tibetan Plateau (TP). Variations of microparticle and major ions (e.g. Mg2+, Ca2+) concentrations in snowpits show that the values of the microparticles and ions in the non-monsoon seasons are much higher than those in the monsoon seasons. Annual flux of microparticle deposition at ER is lower than those at NQ and GL, which could be attributed to the long distance away from the possible dust source regions as well as the elevation for ER higher than the others. Compared with other remote areas, microparticle concentrations in the southern TP are much lower than those in the northern TP, but still much higher than those in Greenland and Antarctica. The seasonal and spatial microparticle variations are clearly related to the variations of atmospheric circulation according to the air mass 5-day backward trajectory analyses of HYSPLIT Model. Resultingly, the high microparticle values in snow are mainly attributed to the westerlies and the strong dust storm outbreaks on the TP, while the monsoon circulation brings great amount of precipitation from the Indian Ocean, thus reducing in the aerosol concentrations. 相似文献
7.
KANG Shi chang QIN Da he YAO Tan dong PAUL A. Mayewski SALLIE Whitlow 《中国地理科学(英文版)》2000,10(3):218-225
Investigations of atmospheric composition in the Himalayas has been limited in both temporal and spatial scales, mainly due to difficult logistics. Ideal sites for monitoring atmospheric composition and its evolution should be free from local pollution and representative of the remote troposphere (HUEBERT et al., 1980). As the Himalayas are far removed from highly industrialized regions they provide suitable locations to monitor the chemistry of the remote troposphere and to study the evolu… 相似文献
8.
利用遥感影像反演积雪的范围与雪深是当前的主流方法之一,但是由于卫星影像获取的时效性约束,存在难以表示积雪动态信息、模型通用性弱、对遥感资料质量依赖程度高等问题。三维粒子系统作为一种优秀的不规则模糊物体模拟方法,可以大大提高自然现象三维场景的真实感。本文提出了一种基于三维例子系统的雪灾模拟与实时绘制方法,将降雪的物理属性及几何属性转化为雪粒子属性,并以物理引擎为基础,建立基于三维粒子系统的积雪模型和融雪模型,模拟降雪过程并计算积雪范围和积雪深度,真实再现雪灾场景和发展趋势,方法简单、可操作且约束较少。实验表明,该方法的模拟结果与实际灾情具有较强的一致性,算法具有可靠性,并能再现三维雪灾场景,具有实时性和逼真性。 相似文献
9.
ImODUcrIONWindisantheortantagentfortransportationofdryandfinemateriaIsfromcontin-entStooceans.MaterialloadfromriversandcoastalerosiondepositSrnaitilyinestuaries,coastalregionsandontheinnercontinentalshelves.MinoramountSentCfopenoceans(Robeft,l982).DuetoconstruCtionofreservoAsonrivers,therivers'matCrialloadstotheseahavedroppedgreat1y.Forinstance,theloadoftheHuangheRiverintotheBohaiSeawas2O.4xlO9tinl958,butoIilyo.9xlO9tinl987.Meansedirnentdischargeredued36%duringtheperiodfroml98ltol989… 相似文献
10.
Acidic species, such as Nitrate, in polar snow and firn layers are “reversibly” deposited, and are sufficiently volatile to undergo significant postdepositional exchange between snow/firn and the atmosphere. Through comparison of the snowpit and snowpack nitrate concentrations from central East Antarctica and the headwater of ürumqi River, we conclude that the nitrate peaks in the uppermost surface snow layers in central Antarctica are not related to an atmospheric signal and must account for post-depositional effects. Such effects, however, are not found in the surface snowpack nitrate profiles from the headwater of ürumqi River. Two reasons may account for the post-depositional difference. At first, nitrate in the polar snow and firn layers appears to be hydrated ion, which can be taken up by the atmosphere, while at the headwater of ürumqi River it seems mainly as mineral ion, which assembles the behavior of aerosol-derived species that are “irreversibly” deposited and do not undergo significant post-depositional exchange with the atmosphere. Secondly, the chemical features of the snow and ice on the Antarctica are mainly determined by wet deposition, to the contrary, dry deposition is more significant at the headwater of lUrumqi River than that on the East Antarctic Plateau. 相似文献
11.
Sand/dust storms are some of the main hazards in arid and semi-arid zones. These storms also influence global environmental changes. By field observations, empirical statistics, and numerical simulations, pioneer researchers on these natural events have concluded the existence of a positive relationship between thermodynamic effects and sand/dust storms. Thermodynamic effects induce an unsteady stratified atmosphere to influence the process of these storms. However, studies on the relationship of thermodynamic effects with particles (i.e., sand and dust) are limited. In this article, wind tunnel with heating was used to simulate the quantitative relationship between thermodynamic effects and particle movement on different surfaces. Compared with the cold state, the threshold wind velocity of particles is found to be significantly decrease under the hot state. The largest decrease percentage exceedes 9% on fine and coarse sand surfaces. The wind velocity also has a three-power function in the sand transport rate under the hot state with increased sand transport. Thermodynamic effects are stronger on loose surfaces and fine particles, but weaker on compacted surfaces and coarse particles. 相似文献
12.
《山地科学学报》2021,(7)
Numerous lakes in western China are excellent sites for understanding environmental change. However, what dominates rare earth element(REE) variations are still under debate in the lake environmental research. In this study, we selected 28 surface sediment samples from 17 lakes(i.e. largescale lakes, small water bodies, etc.) in the QinghaiTibet Plateau and Xinjiang area. These samples were analyzed to reveal the behavior of the REEs and major elements. These REE patterns are characterized by light rare earth element(LREE) enrichment, weak Ce anomaly(0.84-0.98, 0.94 on average) and negative Eu anomaly(0.53-1.00, 0.67 on average). The homogeneous REE patterns may reflect similar REE of the source lithologys. However, the REE abundances showed some significant differences. In this study, water chemistry data analyses inferred that the highly REE values appear possibly in the saltwater lake, and also related to carbonate mineral, whereas p H played a minor role in REE concentrations. In large-scale lakes(e.g. Lake Bosten and Lake Ulungur), the results showed that the relatively larger REE values are in the margins of lakes. Moreover, lower REE contents are towards the central region. Comprehensive study suggested that five major factors control the REE contents:(1) The REE tends to increase with the increase of the weathering intensity.(2) Likewise, heavy mineral(i.e. rutile, anatase, zircon, etc.) are probably primary in these sediments because they are highly enriched in the REE.(3) The contribution of Fe-Mn oxides is significant in sediments because their concentrations highly correlate with the REE.(4) The carbonate mineral(mainly calcite) played a significant role on the REE values in the lakes because the REEs are incorporated into the carbonate minerals generating the low REE concentrations.(5) Major element analysis, mineral analysis, and grain-size data analysis showed that the REE distribution is chiefly influenced by finer grain-size component of lake sediments due to the decreasing proportion of quartz and feldspar than coarser one. Moreover, the clay minerals in finer grain-size sediments can highly absorb the REE. 相似文献
13.
The fresh snow density was observed with snow analyzer (Snow Fork) at Tianshan Station for Snowcover and Avalanche Research, Chinese Academy of Sciences from February 21 to March 5, 2009. Results show that fresh snow density increases from the 5th h to the 291st h after the snowfall, with an average rate of increase of 4.0×10-4 g/(cm3·h) (R2 = 0.943). Analysis shows that fresh snow density is negatively correlated with the compac-tion rate of fresh snow (R2 = -0.960). Inversely, it is positively correlated ... 相似文献
14.
李秉新 《地球科学与环境学报》2001,23(3):30-32
论述了矾山钛榴石的矿物学特征、矿物化学、X光粉晶衍射鉴定特征和钛榴石环带电子探针数据以及其形成的地质背景,得出矾山钛榴石为同化混染成因的结论. 相似文献
15.
King George Island, situated in the South Shetland Islands archipelago, is one of the most visited sites in Antarctica. Antarctica attracts much attention because it is one of the most sensitive areas under the influence of global warming. To understand its hydrochemistry characteristics, we collected various types of water samples, including samples from streams, meltwaters, ground waters, snow and ice from around the Great Wall Station, Fildes Peninsula, King George Island, from January to February, 2015. Major ions, alkalinities, silicate, pH, dissolved oxygen, temperature, and electric conductivities were measured. Several approaches were applied to identify processes that af fect the hydrochemistry on Fildes Peninsula, including ternary diagrams, principal components analysis and cluster analysis. Our data suggest that atmospheric seasalt deposition is the main factor controlling the hydrochemistry on Fildes Peninsula. After atmospheric influences were corrected for seasalt, we defined the weathering of local rocks to be another important factor on the Peninsula's hydrochemistry. Processes such as Ca dissolution from the Ca-bearing basalt, Si loss through secondary mineralization and biological uptake influence the chemical composition of runof fs on the peninsula. Cluster analysis identified 4 groups of streams based on their hydrochemical features, which reflect their original weathering characters under icecap and the combined effects with melt snow, biological activity and the anthropogenic input. 相似文献
16.
SNOW HAZARD REGIONALIZATION IN CHINA 总被引：1，自引：1，他引：0
For the zoning of snow hazard in China, on the principles of (a) comprehensive analysis integrated with dominant factors, (b) multi-level division, and (c) serving the agriculture and stock-raising, transportation and communication, we first classified China into two large zones according to the situation of snow or no snow distribution. Secondly, based on the climate and landform, properties of snow cover and main features of snow hazard, the large zone of snow hazard can be classified into three second-level regions. In order to obviously reflect the difference of snow cover quantity and snow hazard type as well as hazardous degree, twenty subregions (third-level) of snow hazard are further divided in detail. In addition, the boundaries and the principal features of the differences between the various snow hazard regions are provided. 相似文献
17.
The vertical temperature profiles of snow and sea ice have been measured in the Arctic during the 2nd Chinese National Arctic Research Expedition in 2003(CHINARE2003).The high-resolution temperature profile in snow is solved by one-dimensional heat transfer equation.The effective heat diffusivity,internal heat sources are identified.The internal heat source refers to the penetrated solar radiation which usually warms the lower part of the snow layer in summer.By temperature gradient analysis,the zero level can be clarified quantitatively as the boundary of the dry and wet snow.According to the in situ time series of vertical temperature profile,the time series of water content in snow is obtained based on an evaluation method of snow water content associated with the snow and ice physical parameters.The relationship of snow water content and snow temperature and temporal-spatial distribution of snow water content are presented 相似文献
18.
《山地科学学报》2020,17(3):542-555
This study explores the relationship between the species composition of lichen and vascular plant species with microtopography at fine scale. We conducted our study in Hardengervidda National Park, Norway. Specifically, we aim to test whether the species richness of different plant lifeforms peaks at middle of the microtopography gradient, and then explain the observed patterns with an aid of snow cover gradient along microtopography and snow cover. We sampled 69 species of vascular plants and lichens in 151 plots of 4 m~2 along 23 transects during summer on Tronsbu, Sandhaug and Besso. Detrended correspondence analysis(DCA) was performed to explore how microtopographical gradient was related to the variation in the species composition. One-way ANOVA was performed to test the microtopographic variability in species richness.Afterwards, generalized linear model(GLM) was used to reveal species richness patterns along the snow cover gradient. The first axis in DCA represents the complex gradient from snow free ridge to wet snowbed habitats and the second axis represents a gradient from acidic to calcareous sites. Lichen's species richness is greater in ridge than in snowbeds, while all other life forms follow the opposite trend. Species richness for total plant species, vascular plant species and herbaceous plant species increased with increase in weighted average snow indicator value(WASI), whilst species richness for lichen species declined substantially towards the maximum WASI value. In contrast, species richness for dwarf shrub species showed a unimodal relationship with WASI. This study shows that liquid water availability provides a good potential explanation for species composition and richness in mountains, which is controlled by snow cover and prevalent wind direction. 相似文献
19.
A WRF-Chem model including a comprehensive gas-phase nitrogen chemistry module was used to simulate a severe dust event appearing in the eastern China on 19-25 March, 2002. The modeling result well reproduced PM10 concentrations in various distances from the dust sources and the transport pathway of the dust strom. The results showed that both the concentrations and the dry deposition fluxes of PM10 increased over the China seas during the dust event following the passage of a cold front system. The maximum fluxes of PM10 in the Yellow Sea and the East China Sea during the dust event were 5.5 and 8.4 times of those before the event, respectively. However, the temporal variations of the dry deposition fluxes of particulate inorganic nitrogen differed over the Yellow Sea from those over the East China Sea. Nitrate and ammonium in the whole northern China rapidly decreased because of the intrusion of dust-loaded air on 19 March. The dust plume arrived in the Yellow Sea on 20 March, decreasing the particulate inorganic nitrogen in mass concentration accordingly. The minimum dry deposition fluxes of nitrate and ammonium in the Yellow Sea were about 3/5 and 1/6 of those before the dust arrival, respectively. In contrast, when the dust plume crossed over the Yangtze Delta area, it became abundant in nitrate and ammonium and increased the concentrations and dry deposition fluxes of particulate inorganic nitrogen over the East China Sea, where the maximum dry deposition fluxes of nitrate and ammonium increased approximately by 4.1 and 2.6 times of those prior to the dust arrival. 相似文献
20.
The Seasonal Variabilities in the Concentration of Atmospheric Aerosols over Qingdao, China 总被引：2，自引：0，他引：2
SHENG Lifang FU Ying QIU Mingyan GAO Huiwang 《中国海洋大学学报(英文版)》2005,4(4):383-390
Mass concentrations of Total Suspended Particles （TSP） and size-segregated particles were obtained from July 2001 to June 2002 in Qingdao to characterize the seasonal variations of atmospheric aerosols and to show the impact of dust events on the air quality in Qingdao. Data on size-segregated aerosols show that 73.74% of the TSP mass concentration is contributed by particles with diameters less than 11 μm. Particles with diameters less than 1.1μm have a higher concentration during the winter. In spring, larger particles tend to have higher mass concentrations. Bimodal particle size distributions have been observed, with maxima around 4.7-7 μand 0.43-0.65 μm in the winter season, and 7-11 μm and 0.65-1.1 μm in the autumn season. Measurements made during the dust events in March 2002 show high concentrations of particles in the size range 2.1-7μm. 相似文献