Glacier motion is composed of plastic deformation of the ice， sliding of ice over its bed and deformation of the bed itself. Among these three components， basal sliding is a significant factor. And its law， which represents the relationship between the sliding speed， the shear stress at the base of the glacier and the characteristics of the ice bed， is the basal boundary condition of the glacier dynamic process. The estimation of basal sliding plays an important role in the study of glacier motion， internal stress distribution and mechanism of glacier anomaly. This study systematically reviews the development of glacier sliding and its existing estimation methods， which gradually expand from only considering the relationship between shear stress and ice bed roughness to taking into account the comprehensive influences of effective pressure and hydrologic process under the ice. We dissect the structures and functions of existing models， and then analyze the main problems and challenges of these methods， in order to provide references for further improvements of this model. Future studies on glacier basal sliding should be based on big remote sensing data and new technique， and focused on coupling the influence of subglacial hydrological processes， so as to promote the integrated study of climate change-glacier material balance-glacier dynamic response process.

River ice is a common phenomenon of water freezing in the cold season， which will have a series of important effects on hydrology， transportation， and the environment. River ice monitoring can not only provide a reference for the study of the water cycle and water resources management in cold regions， but also provide a basis for water conservancy project construction and shipping safety. Remote sensing technology can realize the rapid observation of a large range of river ice with low cost and high temporal and spatial resolution， which is considered as one of the effective methods to monitor river ice. In this paper， the research and application progress of remote sensing monitoring of river ice were described objectively in the order of different types of sensors. Multi-spectral remote sensing data have been widely used because of their high spatial and temporal resolution. They are mainly used to monitor the distribution range and area of river ice. Microwave remote sensing data are often used to monitor the type and thickness of river ice due to their unique penetrating ability. Secondly， the future development trend of river ice remote sensing monitoring technology as well as the opportunities and challenges of river ice remote sensing were discussed. At present， some new technologies such as Unmanned Aerial Vehicles （UAV） and Ground-Penetrating Radar （GPR） have also been applied to the field of remote sensing monitoring of river ice. In the future， multi-sensor joint monitoring should be strengthened to improve the monitoring effect. River ice remote sensing research needs to be combined with hydrological and climate models to realize the mutual-cooperation and complementary advantages of remote sensing observations and the models， and promote more in-depth research on river ice monitoring.

Greenland Ice Sheet is one of the two largest ice sheets on the planet. Under the background of climate warming, the melting of the Greenland ice sheet and its contribution to sea level rise has become an international hot issue. The whole melting of the Greenland ice sheet can cause the global sea level to rise by about 7.3 meters. However, the dynamic mechanism that affects the mass balance of ice sheet is still unclear and is the greatest uncertainty source for predicting the rise in sea level in the future. The National Key Research and Development Program of China “A Study of the Monitoring, Simulation and Climate Impact of Greenland Ice Sheet” conducts monitoring and simulation studies on the key processes of instability of the “ice sheet-outlet glacier-sea ice” system, and establishes a satellite-airborne-ground integrated observation system, supporting the numerical simulation and impact research of the ice sheet and its surrounding sea ice, laying the foundation for long-term monitoring and international cooperation in Greenland. This program will work to reduce the uncertainty of sea level change projections by improving the ice sheet dynamic model forced by the ice core records, reveal the driving mechanism of sea ice changes around the ice sheet, focusing on the Northwest Passage, evaluate and forecast the navigation window period. The results of the project will deepen the understanding of the changes and impacts of the Arctic cryosphere, serve the safe navigation and operation of the Northwest Passage, and provide scientific support for the comprehensive risk prevention of coastal zones in China.

On account of the latest community Noah land surface model with multi-parameterization (Noah-MP) schemes and its uncertainty breadth in simulation results being difficult to be determined, this study assessed the sensitivity of snow to physics options using meteorological data from the Altay Station in northern Xinjiang. The Noah-MP physics ensemble simulation with the total number of 13 824 was designed without the consideration of the uncertainties of forcing data and parameters. The natural selection approach was used to analyze the sensitivity of physical processes. Based on the results of sensitivity analysis, the uncertainty of ensemble simulation results was further discussed. The results showed that snow was sensitive to the physical processes of surface-layer exchange coefficient, partitioning precipitation into rainfall and snowfall, lower boundary condition of soil temperature, and first-layer snow or soil temperature time scheme; Uncertainties in multi-parameterization ensemble simulation experiments were mainly from sensitive physical processes under the condition of disregarding uncertainties of forcing data and parameters. After removing the parameterization schemes that notably reduced simulation performance in sensitive physical processes, the uncertainty breadth in ensemble simulations decreased significantly. Finally, an optimal combination group of parameterization schemes for this station was configured.

The snow cover days were extracted out of the snow data on depth distribution from 1979 to 2016 in China, combined with temperature, precipitation, humidity, sunlight and wind speed and other meteorological data, by taking advantage of traditional statistical methods and GIS spatial analysis methods, to study the temporal and spatial variation characteristics of snow cover days in northeast China region in the past 40 years, and to analyze their relationship with climatic factors. It turned out that the average annual snow cover days were 93 d in northeast China region, having an increasing trend, the rate was 0.6 d/10a, and the maximum average annual snow cover days appeared in 2013. Snow cover days in spring dominate the changes of the average snow days all year around. The snow cover days in northeast China region were affected by latitude, geography and land-sea thermal difference, which gradually decreased from north to south, and the maximum value appeared in the Da Hinggan area. Precipitation, humidity and snow cover days are positive correlation, and temperature, wind speed and sunlight are negative correlation. The correlation between climatic elements and snow cover days is as follows: temperature>humidity>wind speed>sunlight>precipitation. The influence of climatic elements on the seasonally frozen ground region is more significant than that in the permafrost region. The results show that temperature is the main factor that affects the average annual snow cover days in northeast China region.

Snow cover is an informative indicator of climate change because it affects local and regional surface energy and water balance, hydrological processes and climate. Passive Microwave (PM) works all weather and round the clock and penetrates clouds and snow. Passive microwave remote sensing data have been widely applied to retrieving snow depth and snow water equivalent in the past few decades. Recently, the snow depth retrieval study has rapidly developed. This paper reviewed the research progress of snow depth and snow water equivalent inversion algorithm using PM data at home and abroad. Firstly, the basic theory of passive microwave remote sensing snow monitoring and passive microwave remote sensing data were introduced. Then, the current snow depth and snow water equivalent inversion algorithm were summarized into four categories: ① A statistically based linear inversion algorithm; ② An inversion algorithm based on microwave transmission snow model; ③ A nonlinear inversion algorithm based on prior knowledge; ④ Data fusion and data assimilation. Afterwards, the commonly used seven kinds of snow data products were introduced, and several factors affecting the snow depth and the snow water inversion accuracy were discussed. Finally, the possible direction of future snow parameter inversion research was prospected.

This paper focuses on revealing the status quo and variation of glaciers in the western region of Tanggula Mountains. The ratio threshold, NIR water identification and visual interpretation were used to extract the boundary of glaciers based on Landsat data (TM/ETM+/OLI) from 1990 to 2015. In particular, the NIR water identification is a new method to extract glaciers from water, which is suitable to improve the traditional method of ratio threshold. This study used spatial interpolation method to evaluate temperature and precipitation changes. The kriging interpolation method was adapted to manipulate and to extract the appropriate data based on ten weather stations. Comparing to the variations and characteristics of glaciers and climate change from 1990 to 2015, we concluded that glacial retreat in the western region of Tanggula Mountains was serious. The glacier area reduced from 1 693.65 km² to 1 490.81 km², respectively, in 1990 and 2015, in general, approximately 202.84 km² (11.98%) of glacier area has been retreated in the last 25 years. Moreover, the rate of glacier decline after 2000 was much faster than the last decade of the 20th century. In addition, the decreased area of glaciers in the lower altitude basins below 5 000 meters occupied 94.84% of the total change area while the glacier above 5 000 meters almost had no change. The kriging interpolation of the meteorological data indicated that the southeast of the study area was damp and hot while the northwest was cold and dry. The characteristic of temperature distribution from the northwest to the southeast presented from low to high, and precipitation increased in the first of the study period and then decreased but both of them were not very significant. In short, the temperature of study area was increased more prominently since 2000, while the precipitation change was very weak. The mean annual temperature and precipitation of 1980-1989a, 1990-1999a, and 2000-2013a were -3.53 ℃, -3.20 ℃, -2.22 ℃, and 384.49 mm, 354.27 mm, 428.13 mm, respectively. The study found that the glacier change was consistent with temperature variation in spite of the adverse effects of increased precipitation. Therefore, the research concluded that the precipitation change was not more significant comparing to temperature change. In other words, the main reason of the rapid decrease of glaciers in study area was likely due to the rise of temperature.

In order to assess the performance of the common temperature-index melt model at both spatial and temporal scale in Qilian Mountains, we performed the sensitivity and uncertainty analysis on the parameters of a common temperature-index method and evaluated the glacier mass balance on a small alpine glacier, which is separated into two relatively independent branches, with the daily mass balance and the meteorological data in the summer of 2011 and 2012. Sensitivity analysis was conducted by perturbation analysis and uncertainty analysis was carried out by Generalized Likelihood Uncertainty Estimation (GLUE) for different conditions. The results showed that the temperature-index method could properly capture the diurnal variability of the glacier mass balance. But strong equifinality of model parameter existsed in model calibration due to the uncertainty in the parameters. The model was very sensitive to changes in the value of K_ice, followed by the K_snow and T_s. It was also found that the GLUE approaches could estimate and derive the posterior distributions of 3 parameters properly. Moreover, there existed an acceptable range, which ensured high precision under different conditions.

Large-scale, low frequency modes such as the North Atlantic Oscillation(NAO)and blocking, have an important modulation on the northern hemisphere weather and climate. In this paper, the physical mechanism studies on inter-decadal and decadal variability of NAO and blocking were summarized. The relationship between NAO regime transitions and the interannual variability of NAO in winter during was examined by using a statistical approach. The time-space relationship between NAO and European blocking were discussed. Based on two extreme cold and snowstorm events, the impacts on local weather especially the extreme events within the life cycle (two weeks) of the NAO and blocking were further examined. It was found that the frequently occurrence of the Eurasian extreme snowstorm was closely related to the special combination of NAO and blocking regime. In addition, the development of theoretical modes for NAO and blocking was discussed and issues that remain to be solved were proposed.

In recent years, melting and calving happen in the Antarctic ice shelves. In this paper, seven periods of coastlines were applied to provide an analysis of the ice front changes of Ross, Filchner-Ronne and Amery ice shelves with the inclusion of 1997 and 2000 Radarsat products, 2003/2004 and 2008/2009 MODIS products and 2006, 2012, 2015 coastline which were extracted from MODIS images. Change area, SCE (Shoreline Change Envelope) and NSM (Net Shoreline Movement) were applied to analyze the variation of the ice shelf front. The results shows that, the ice front of Amery ice shelf has advanced since 1997 and the total outward extension distance of the ice front was about 20 to 25 km while the advance area reached 3.03×10³ km². Ross ice shelf and Filchner-Ronne ice shelf continued to advance after ice calving events under the driver action of glacier. However, the advance area was less than the retreat area and the net change area is respectively -9.39×10³ km² and -5.86×10³ km². The retreat distance of the collapse area were up to 53 km and 39 km in the two biggest ice shelves.

Vulnerability and adaptation study of the cryosphere and its changes is a novel research direction in the field of cryospheric research. The exploration and understanding of vulnerability concept of the cryosphere and its changes is the prerequisite and foundation of the study system. In addition, the research content includes social and economic impacts of cryospheric changes, which is the breakthrough point, the vulnerability and adaptation assessments of the different scales of human-environment systems to the effects of cryospheric changes, which is the bridge between impact and adaptation, and the option and pathway of coping with and adapting to the effects and risk of cryospheric changes, which is the goal. In this paper, the vulnerability concept of Chinese cryosphere and its changes is firstly defined and discussed. Impact, vulnerability and adaptation as a main line, the research contents and their respective key scientific issues of social and economic impacts, vulnerability and adaptation of cryosphere change, vulnerability assessment model, and study scale are elaborated. Thus, a research frame of the vulnerability and adaptation is initially built in the kingdom of Chinese cryospheric sciences. The component of Chinese cryosphere is various, including glacier, frozen ground, snow, river ice, lake ice, and sea ice. The variations and impacts of these elements are complicated, and different from one region to another. The vulnerability and adaptation study pattern and spatial layout of Chinese cryosphere and its changes are determined in the paper on the basis of the consideration of abovementioned diversity, complexity and regional differences. The applied study on cryosphere change adaptation of co-design and joint participation for different stakeholders should be strengthened and cryospheric disaster risk, especially gradient risk should also be paid high attention to in addition to the further study of the impact and vulnerability of the cryosphere change.

Glaciers, which are sensitive indicators of climate warming, are generally thinning and retreating at an accelerated rate. Glacier melting has wide-ranging consequences such as sea-level rise, regional water cycle, and water availability. Studies of ice volume change, which is a significant part of glacier studies, are increasingly concerned by more researchers. In this article,volume changes of ice caps and mountain glaciers were discussed. Based on this, study methods of glacier volume or ice thickness change were highlighted. In general, there are four methods of investigating glacier volume change. It has improved from traditional ground-based techniques, empirical equation of glacier area and volume, glacier topographic survey to remote sensing monitoring. Due to its novel, rapid and relatively inexpensive techniques, glacier monitoring using remote sensing technique could effectively solve the limited data of remote location in alpine regions. Remote sensing, GIS and GPS technologies will continue to play a significant role in the estimation of volume or ice thickness of mountain glaciers and ice caps.

Remote sensing is now widely used in glacier classification and monitoring. The synthetic aperture radar is hardly influenced by weather conditions and sensitive to ground wetness and roughness. Meanwhile, it has the penetration ability to ground objects. So it is promising in glacier mapping and monitoring. Until now SAR application in glacier is limited in theory and experiments, which is a hot topic in remote sensing of glacier research. This paper reviews the application of SAR in glacier zones recognition using the scattering property difference, flow velocity generation using InSAR and feature tracking, and glacier thickness monitoring using DInSAR generated DEM. The merits and limitations of SAR for glacier monitoring are investigated, and the promising theory and techniques for SAR to detect glaciers are introduced.

The Features of climate change in Mt.Yulong, southeasten Tibetan Plateau were analyzed using linear regression, MannKendall abrupt test and Morlet wavelet analyses. In addition, the relationship between glacier retreating (Baishui Glacier No.1) and climate warming wasalso analyzed in this study. The main results are showedas follow: ① The annual mean temperature, precipitation have an increasing trend, withinclination rates being 0.15℃/10a and 9.0 mm/10a;annual temperaturedramatically ascend in 1998 with the change values 0.7 ℃; Morlet waveletsin annual temperature andtemperature in dry season mainly have a 10 to 15year periods,while annual precipitation amount and the precipitation in rainyseason presented a quasi 10 year periods. ②Prior to 1998, the important meteorological factor influencing the change of Baishui Glacier No.1 are temperature and precipitation, while in the following years, temperature plays a more important role in affecting its retreat and advance; The main characteristic ofverticalclimate change in Mt. Yulong (1982/2009) is that the cold season shortens and temperature rises with elevation, and the maximal value of increased temperature in glacier zone is 2.2~2.5 ℃, resulting in greatly accelerated glacier ablation.

This paper analyzes the variation of meridional temperature gradient (MTG) over mid-latitude and high-latitude of Northern Hemisphere continents during last 100 years using observational data. It is found that MTG over high-latitude of Northern Hemisphere continents has an increasing trend, but the simulation results of CMIP5 models show a decreasing trend. Results of this study showed the decrease of MTG over the high-latitude continents of Northern Hemisphere calculated by CMIP5 historical simulations mainly because the models of CMIP5 exaggerated ice-albedo feedback over high-latitude regions. A series of simulation results by energy balance climate models showed that ice-albedo feedback amplified the magnitude of warming in the global warming induced only by carbon dioxide, and the magnitude of warming in highlatitude was much larger than that in low-latitude regions. Along with global warming, ice-albedo feedback has little influence on MTG in low-latitude, but can induce the decrease of MTG in high-latitude regions.

Cryospheric changes and their impacts are receiving wide attention from international scientific and social communities. Here, we summarize the present hotspots of international cryospheric sciences and hence conclude four major aspects of it. They are respectively ① mechanism of cryospheric changes, ② interaction of cryospheric and other spheres of climate/earth system, ③ impacts of cryospheric changes, and ④ adaptation methods and strategy to these changes. Among the four areas, mechanism study is the basis for cryospherc sciences, interaction between different spheres is the currently developing aspect of the field, impacts of cryospheric changes are increasingly studied and yet still have large gaps, while adaptation study is still an iniative nowadays. For the above four aspects, there are key issues for each of them. For instance, dynamic responses and spatial/temporal differences are the key challenges in the mechanism studies. Rational and precise description on physical/chemical/geochemical processes of cryosphere is one of critical issues on improving the climate models. Scoping the spatial/temporal scales, as well as defining the influence degree is the key gaps in studying the cryospheric impacts. Methods and related index system for vulnerability assessment is the key issue in the study of the adaptation strategy of cryospheric impacts. Cryospheric sciences are developing towards, in the near future, the coupling of cryoshperic components into climate system in global scale, detecting the impacts of cryospheric changes using multiple and integrated methodology, and innovated approaches in adaptation.

The Greenland Sea, a marginal sea of the Arctic Ocean, accommodates ice flux from the Arctic. The Greenland Sea ice edge is affected by ice export from the Arctic Ocean and also by local sea ice melting and freezing processes. The sea ice concentration product inverted from brightness temperature data on the AMSR-E microwave sensor from January 2003 to June 2011 is used to discuss the variability of the Greenland Sea ice edge in this paper. The study shows that the Greenland Sea ice edge did not only show annual periodic variations, but also significant semiannual periodic variations associated with sea ice extent changes in spring and autumn. The maximum of winter sea ice edge had a decreasing trend which demonstrated sea ice extent decreasing caused by Arctic warming in winter, and the minimum of summer sea ice edge had a increasing trend caused by higher sea ice export from Arctic Ocean in summer. 2003 and 2004 were the year Greenland Sea ice melt most in summer. In 2007, the Arctic Ocean had the largest ice extent, while the Greenland Sea had the least ice extent that demonstrated more ice export from Arctic Ocean than the other years. In addition, surface water runoff from ice melting in summer on the Greenland had a certain impact on the variability of sea ice edge. Meridional wind in Fram Strait, which drove ice transport from the Arctic Ocean to the Greenland Sea and then produced lagging effect on the distribution of the Greenland Sea ice edge, played a more important role than local wind field on ice edge variations.

 Due to the difficulties in outlining glacier using optical imagery methodology hampered by debris-cover, a new method using the combination of interferometric coherence and surface velocity to delineate debris-covered glacier limits is presented. Coherence images from difference interferometry of ALOS PALSAR data were classified using Maximum Likelihood classifiers (ML) based on Iterative Self-Organization cluster algorithm (ISO) to discern glacier limit from non-glacier area. The results were compared with historic limit from aerial photos and validated by GPS ground-truth data. The surface velocity derived from SAR feature-tracking was employed to validate the results and to discuss the glacier dynamic change. The glacier (coded 5Y663D0009) in Kongur Mountains was tested. We find that the long glacier tongue shows high coherence with low surface velocities while the middle moraine area shows low coherence with higher surface velocities. This implies that the interferometric coherence is a confident judgment for active or inactive debris-covered glacier area. This will make it possible to monitor glacier dynamic change under climate warming. The reliability and uncertainty were discussed.

This paper is dedicated to gauging velocities using high resolution GPS during the period from June to September in 2011, making explorative research and comparatively analyzing with other typical glaciers in Baishui No.1 Glacier, which is a representative maritime glacier in Mt.Yulong. It is suggested in the result that special characteristics of velocity exist in Baishui No.1 Glacier, which revealed obviously as its style, monthly range from 2.34 m to 4.74 m, 6-10 times faster than other kinds in the same area. Comparatively, the velocity of Baishui No.1 Glacier is half of that in Palong Glacier No.94, which demonstrates that velocities are proportional to their scale. In addition, the terminus of Baishui No.1 Glacier evenly elevated 4381m above sea level, retreating of an identical rate over the past decade, which is the same indicator as the past 10 years’ under the background of climate change.

This paper reviewed the recent progress in the study of englacial and subglacial drainage system of glaciers. Englacial and subglacial drainage system of glaciers play an important role in glacier runoff process, ice motion anomalies, glacier erosion rate and sedimentation processes. Efficiency of englacial and subglacial drainage system controls the runoff response from glacial catchments by modifying the input and storage rate of liquid water from ice/snow melting and rainfall. It also has important implications for glacial dynamics, through its influence on basal stress distributions or subglacial lubricating by changing the englacial and subglacial hydraulic conditions. The status of subglacial drainage system also affects physical and chemical processes at the ice-bed interface, controlling sediment and solute dynamics in proglacial streams. Furthermore, climate conditions influence glacier ablation processes by the change of the ice melting intensity, glacier melting area and glacier ablation period, which then induce the variation of subglacial water storage and drainage processes. Coupled processes between subglacial hydrology and glacier dynamics therefore should be concerned in the future related research. 

Soil Freeze-Thaw processes and parameters play an essential role in land surface processes, climate models, global change and other critical aspects. Since passive microwave is sensitive to soil moisture, and has a high revisit frequency, it is suitable for the monitoring of soil Freeze-Thaw processes. Research achievements in microwave remote sensing of frozen soil are reviewed and discussed in this paper. According to the research demands including frozen soil radiation simulation and globally monitoring of frozen soil, several current scientific issues are  proposed and analyzed. The ability of microwave remote sensing of Freeze-Thaw processes over complex landscapes involving soils, snow cover and vegetation cover is well evaluated. A preliminary research proposal  is presented for addressing these issues.

Based on the snowpit samples collected at the accumulation zone of Glacier No.1 at the headwaters of Urumqi River in the Tianshan Mountains from November 2004 to October 2005, nitrate (NO^-₃) concentration in snowpacks is analyzed. Seasonality is displayed for the mean NO^-₃ concentrations in snowpacks, and the concentrations are higher in the dry season (from November to March) and lower in the wet season (from April to October). At the upper section of snowpacks, the spring-formed NO^-₃ concentration peaks  are  diluted significantly in the summer, according to the elution effect; for the whole snowpacks, the NO^-₃ concentration peaks relocate downward. In the vertical profile of snowpack, a transition layer appears at a distance of 70~80 cm to superimposed ice layer; the elution effect above the transition layer is much stronger than that below, and the concentration above the layer is higher than that below. With 20%~60% loss of content during the strong elution period in the postdepositional process, the environmental information is recorded in the ice.

A contrastive study of the classical degree-day model and the enhanced temperature-index model, incorporating the hourly global radiation, were present on Koxkar Glacier, a mountain glacier on the south slopes of the Tianshan Mountains, in the summer, 2008. The two models were run with three different spatial resolutions of 200 m, 100 m and 50 m contour interval, to test their applicability to glacial ablation with low data requirement. Hourly solar radiation was estimated by using parameterizing transfer theory, combind with FY 2C and NCEP/NCAR data. The performance of simulated and measured incoming shortwave radiation showed good consistent relationship, with a determination coefficient R²=0.74. Ablation computations of three sub-periods, using the classical degree-day model, indicated evident temporal variation of degree day factors over the whole summer. With spatial resolution increased, the both models can give good results, especially when the spatial resolutions was 50 m contour interval. It found that the enhanced temperature-index model can get better result than the simple degree-day model with spatial resolutions of 200 m and 100 m contour interval. However, there was no evident improvement by using the enhanced temperature-index model when the spatial resolution was 50 m contour interval due to the uncertainty of simulated incoming shortwave radiation.

By using the date of snow cover days and snow depth of 17 weather stations which above 1 000 m above sea lerel during the year of 1961-2006 in Tiashan Mountain, Xinjiang Uighur Autonomous Region, china, the inter-annual temporal and spatial characteristics were analyzed. Based on the time of the most snow depth days appeared, the 17 weather stations were divided into 4 types, and by integrating the change trend of the snow cover days and snow depth, we found three types of change trend. The results showed that: ①There are four snow depth types in Tianshan Mountains. The most snow depth occurs in January, February, March and double maximal values. The month of the most snow depth has a good relationship with the elevation. ②Both the snow cover days and maximum snow depth are both increase. Winter snow cover days occupy 50 percents of the whole year and, the maximum snow depth occur frequency became increasing trend in the 90th. ③Based on the change trend of snow cover days and maximum snow depth, there are three types of snow change. There are no change trend between snow cover days and elevation, but there are an obviously increasing trend between maximum snow depth and elevation. ④Based on the analysis of precipitation, temperature, humidity and the temperature below 0 ℃ days, the main reason of snowcover increase is because of the increasing of winter precipitation and humidity.

The research of the climate and the environmental information in snow and ice can reveal the climate and environmental characteristics of modern times to contemporary, and even reveal that over the last hundreds thousand years, but also through a combination of modern meteorological records, to improve the capacity of predicting the future climate change. Snow and ice plays an important role in the studies of the past global changes; the ice core research is also an extremely important area in studying the past global changes. The record of chemical composition in snow and ice provide a direct or indirect basis for global change research, such as climate change, biogeochemical cycle. Human activities, geological and cosmic events and many other scientific proposition′s study. These records include the stable isotopes, heavy metals, particulates, aerosols, black carbon, ion. The ion chemical study of snow and ice has an important position. To analyze the uncertainty in detecting the anion in snow and ice by ion chromatography, find out the factors which influence the uncertainty , evaluate the uncertainty and give out the uncertainty of evaluation which faithfully reflects metrical credibility and accuracy.

The research of the radiation budget is valuable to reveal the hydrothermal conditions of the modern glacier's development and the interaction between glacier and climate, especially in the regions where the observational data are limit. annual and mean diurnal Variations of the components of radiation are analyzed based on observed meteorological data during October 20, 2008 and October 19, 2009, at an elevation of 5 040 meters of the Laohugou No.12 glacier in the Qilian Mountains. The results are obtained as follows: monthly mean values of air temperature are higher than the surface temperature of glacier, and the atmosphere is the heat source of sensible heat flux on the glacier. The total annual value of the incoming shortwave radiation is 6 937.9 MJ/m² in the region of Laohugou under the action of its high altitude, cloud and terrain. there are 21 days when the value of incoming shortwave radiation is larger than the Solar Constant, and the maximum is 1 675 W/m². Mean diurnal variations of the incoming and reflected shortwave radiation have a single peak curve, and the discrepancy of radiation intensity between spring and summer is feeble, and the smallest in winter. Mean diurnal of the incoming and outgoing long wave radiation appear single kurtosis and single vale, and the radiation intensity appears to be the largest(smallest) in summer(winter), and the discrepancy between spring and fall is feeble. The albedo of autumn and winter are higher than the spring and summer, and the annual average value is 0.74. Diurnal variations of the net radiation have an apparent seasonal change in the daytime. Except the period of from April to August, the net radiation is negative. The output of the radiation on the surface of the glacier exceeds the input during the year.

Antarctic ice sheet ,as an important part of the Earth system, plays a critical role in the global climate change.The understanding of the Antarctic ice sheet will help in making sense of the global climate system, and support exploring the evolution of the global climate in the past, present and the future. By analysing the significant progress of Antarctic ice sheet research in recent years, on the basis of these major findings, observations, as well as the fact that future changes in the discussions，some recent progress is focused, including mass balance, ice cores,subglacial lakes and water system, numerical model of Antarctic ice sheet. Review of the possible future research directions should also be of concern.

      There are a large number of survived glaciers on the High Asia which are the most important freshwater resource for the arid regions in the High Asia. Different glacier systems have different characteristics in mass balance and responses to the global warming as they exist in different environment in the High Asia. Therefore it is necessary to divide and subdivide the grade of glacier systems, analyze their structure and mass balance characteristics, and predict their responding process to climate warming using the theories and methods of glacier system. This paper summarized the researches about glaciers on the High Asia both at home and abroad and pointed out the advantages and disadvantages of them. Then, five sections about the glacier system in the High Asia, i.e., glacier system's grade division, climate and topographical setting, structure characteristics, mass balance characteristics, responding to climate warming and glacier-induced hazards and its influences to environment, are prospected respectively in this paper. As a result, this paper concludes that the grades of glacier systems in High Asia should be firstly divided and sub-divided according to the climate and topographical setting; then, the variation trends of each glacier system is to be modeled, and the utilization programming of glacier resources and prevention measures of glacierrelated hazards will be worked out on the basis of the modeling results.

       Forced by NCEP reanalysis based land surface climate data, NCAR CLM3 was run in an offline way with 6 parameterization schemes (CLM3 default, Douville1995, Roesch2001, Wu2004, Yang1997, Niu2007) for calculation of snow cover fraction (SCF) to investigate the performance of these SCF parameterization schemes in simulating the seasonal variation of snow cover. In comparison with the observations derived from NOAA AVHRR, under the framework of NCAR CLM3, SCF schemes like CLM3 default, Douville1995, and Roesch 2001 underestimate SCF over vast areas, snow lines simulated in these three schemes are located to the south of that in the AVHRR observation, especially in autumn when snow pack begins to establish; Wu2004 scheme also underestimates SCF in the Eurasian continent in autumn; Yang1997 scheme slightly overestimates SCF, especially along the southern border of the snow covered area; Niu2007 scheme which accounts for the seasonal variation of snow density overcomes the positive bias of SCF simulated by Yang1997 scheme to some extent. At the end of spring, snow lines simulated by all the aforementioned 6 schemes are located to the north of the AVHRR observation. Over most land areas with relatively small variation of topography, Niu2007 scheme performs the best. The frequency of low SCF (less than 0.2) or high SCF (more than 0.8) are dominant in both the AVHRR observation and simulations of all the 6 parameterization schemes, moderate SCF (between 0.2 and 0.8) are rare phenomena.

       The Antarctic ice sheet is the largest continental ice on the earth and its mass budget and stability has an important influence on global climate change and sea level rise. Ice radar, or radio-echo sounding (RES), constitutes the principal means by which glaciologists investigate the subsurface properties of the Antarctic ice sheet. In the past fifty years, ice radar has been widely applied to measure ice sheet thickness, internal structure and subglacial morphology. These parameters are fundamental for the calculation of ice volume and mass balance as well as the reconstruction of past snow accumulation and melting rates, ice dynamics and deposition process. Now, RES has covered most regions in Antarctica and provided significant understanding of the interactions between ice sheet and global system. We briefly introduced ice radar and its technical development firstly and then mainly reviewed the progress of ice radar in investigating and researching Antarctic ice sheet thickness and subglacial topography, internal reflecting horizons, subglacial lakes and water systems, subglacial bedrock roughness and crystal orientation fabrics(COF). Finally, the prospect of ice radar in investigating and researching Antarctic ice sheet in the future and our present situation was proposed.

The ion concentrations were studied in both four snow pits on Hami Miaoergou Flat-Topped Glacier and one snow pit on Haxilegen Glacier No.51 of Kuitun river in eastern Tianshan Mountain, and both snow pits were retrieved in 2004. The results show that the Ca²⁺, NO^-₃ and SO^2-₄, particularly Ca²⁺, are major ions in the snow of snow pits in both ablation and accumulation area and also in the ice of snow pits in accumulation area on Hami Miaoergou FlatTopped Glacier, where the relationships among major cation concentrations in snow of snow pits can be revealed by ion concentrations in the ice of snow pits, but the correlation between ion concentrations in the snow of snow pits and elevation is not obvious, which probably can be attributed to the narrow span of elevation and sparse snow pits on glacier. However, the good correlation between ion concentrations in the ice of snow pits and elevation indicates that the elution process weakened gradually with the elevation rise and temperature decrease. The SO^2-₄ and Ca²⁺ particularly SO^2-₄, are major ions in snow and ice of snow pits on Haxilegen Glacier No.51 of Kuitun river, where its ion chemistry in snow pits is different from that on Hami Miaoergou Flat-Topped Glacier, which is most likely related to the geographical location of Hami Miaoergou Flat-Topped Glacier that is located in the leeward site of the Taklimakan desert, Shanshan desert and Gurbantunggut desert, and also probably associated with the elution process in snow pits and altitude effect of deposition flux. The ratios (Cs/Ci) of NH⁺₄, NO^-₃ and K⁺ is bigger than that of Ca²⁺,Mg²⁺ and Na⁺ of snow pits in accumulation area on Hami Miaoergou Flat-Topped Glacier, and also the ratios of Na⁺ and NH⁺₄ is bigger than that of Cl^-, SO^2-₄, Mg²⁺ and Ca²⁺ of snow pits on Haxilegen Glacier No.51 of Kuitun river, which indicate that the signals of Ca²⁺ and Mg²⁺ in snow pits both on Hami Miaoergou Flat-Topped Glacier and Haxilegen Glacier No.51 of Kuitun river may be easier to be preserved in ice cores than other ions in snow pits. This guaranteed studies of ice core and reconstrution of paleoclimate records on these two glaciers.

    In order to evaluate the accuracy of snow water equivalent (SWE) inversion algorithm for passive microwave sensor Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) in Western china, we compared SWE obtained from AMSR-E daily SWE product with the ground measurements from 15 meteorological stations in Tibetan plateau in 2003 and 35 meteorological stations in Xinjiang in January 2004. The results show AMSR-E overestimate SWE both in  these two regions, and RMSE is 21mm and 31.8 mm in Tibetan plateau and Xinjiang, respectively.
    Through incorporating snow fraction factor, a new empirical algorithm estimate snow depth and SWE have been developed in Xinjiang. This new algorithm appeared higher accuracy than AMSR-E does in Xinjiang. Due to complex topography, shallow patchy snow and frozen grounds covered at the Tibetan Plateau, this technique didn't show good results. In future we will focus on how to evaluate and eliminate the effects of these factors quantitatively on SWE retrieval.

Analysis of pH and electrical conductivity in surface snow and snowpit samples collected successively in a weekly basis from September 14, 2002 to September 28, 2004 on the east branch of Glacier No.1 at the Urumqi river head, Tianshan is presented. pH and electrical conductivity in surface snow show obvious seasonal variations, which to some extent are associated with the dominant NE and ENE valley wind. The pH in surface snow is more alkaline and electrical conductivity in surface snow reaches maximum in spring because of the Asian dust storm increases and primary aerosols contribution; pH in surface snow is less alkaline and electrical conductivity in surface snow reaches minimum in winter due to the transformation of primary aerosol to secondary aerosol. During the post-depositional processes (October 4, 2003 September 8, 2004), pH and electrical conductivity in snowpits duing different periods show visible seasonal characteristics and elution processes. The date that the peak value P1 of electrical conductivity in snowpit merges into firn ice is about 40 days prior to that of large particles (Diameter>10μm) merging into firn ice. To some extent, the peak values of pH and electrical conductivity in some snowpits occur near dust layers and their peak values also correspond to the dust layers in snowpits, which imply that dust layers probably had an influence on elution processes of soluble ions. Electrical conductivity observations indicate different elution of some of ions in snowpits, the elution of soluble ions is more likely and easier to happen than that of insoluble ions in snowpits. Furthermore, correlation analysis shows that Ca²⁺ is the key ion determining pH and electrical conductivity in surface snow.

The latest research advance in snow ecology in the world was introduced in this paper, including: six aspects: (1) Snow cover and weather system; (2) Physical features of snow and its relation with ecology; (3) Chemical processes of snow and nutrient circulation; (4) Nival microbe; (5) Snow cover and small animal; (6) Relation between snow cover and vegetation. Some contents that need further study in the future were discussed. Generally, snow ecology study in the world had some extensions as follows: (1) Effects of global changes on snow cover and its feedback mechanism was emphasized; (2) Physical characteristics and its ecological functions of snow cover got more attention; (3) The research reports on nutrient circulation processes in snow ecosystem increased; (4) Study of ultra-structure, physiology, eco-physiology, ecology, life history, biochemistry of snow microbe was developed rapidly; (5) Study of small mammalians was attached importance to physiological and ecological and morphological adaptability; (6) Study interests in physiological and ecological adaptability of plant to extreme environment and its relation with snow environment gradients increased; (7) Process study, quantitative study and numerical simulative study were attached more importance in all research field of snow ecology. Study emphases in the near future include mainly: (1) Feedback processes and its mechanism between snow cover and climate system; (2) Physical multiphase of snow cover and its ecological function; (3) earth circulation processes of snow chemical species, especially C, N circulation; (4) Genetic basic and genic transfer on cold adaptability of snow microbe; (5) Dynamics and nutriology and population dynamics on nival animal; (6) feedback processes and its mechanism in multi-scales among snow, vegetation and climate.

Height determination for Mt.Everest has been carried out 5 times,1966,1975,1992,1998,and 1999 respectively.since 1960 s.The analysis and recomputation of measurement results obtained in the height determination mentioned above are made in recent years.The continuously decreasing trends for the height of snow top at the summit of Mt.Everest are found,and the possible relationship with global warming is discussed.The height for Mt.Everest in global height datum is also presented.