Specific parameters determined from continental ice sheet or glacier cores can be used to reconstruct former climate. Tο use this scientific resource effectively, an information system is needed which guarantees consistent long-term data storage and provides easy access. Such a system, to archive any data of paleoclimatic relevance, together with the related metadata, raw data and evaluated paleoclimatic data, is presented. It is based on a relational database and provides standardized import and export routines, easy access with uniform retrieval functions and tools for visualizing the data. The network is designed as a client-server system, providing access through the Internet with proprietary client software including a high functionality or read-only access to published data via the World Wide Web (www.pangaea.de).

The space-shuttle-based SIR-C/X-SAR synthetic aperture radar (SAR) imaged part of Hielo Patagónico Sur (HPS; southern Patagonia ice field, South America) for five successive days during missions in April and October 1994. A significant meteorological event occurred during each mission, including a major storm in April and a sharp temperature decrease in October. Changes in backscatter are observed for both episodes in X-SAR returns from the mid-portions of one of the two large outlet glaciers in the study area. Ground-station and satellite meteorological, and hydrological data are combined with the daily X-SAR images to interpret changes in glacier surface conditions caused by meteorological events. Effects interpreted from the April storm are (1) wind- and precipitation-influenced surface roughening of a wet snowpack, and (2) the deposition of new wet snow at lower elevation and its subsequent retreat up-glacier. An abrupt decrease in regional temperature during October is thought to reduce the snow wetness and increase grain-size. The changes in the radar-defined glacier zones due to the April precipitation event are subtle, while the October temperature drop causes significant backscatter increases. Our results suggest that trends in HPS glacier surface and near-surface conditions observable from spaceborne SARs are not significantly masked by precipitation events.

In glaciology, snow–firn temperature at 10 m is considered a representation of the mean annual air temperature at the surface (MAAT) of the studied site. Although MAAT is an important parameter in ice-sheet investigations, it has not been widely measured in Antarctica. To measure the 10 m snow–firn temperature in Antarctica, a shallow hot-point drill system is designed. In this simple and lightweight system, a hot-point drill can melt boreholes with a diameter of 34 mm in the snow–firn to a depth of 30 m and a temperature sensors string can measure the borehole temperature precisely. In the 2018/19 field season, 16 boreholes along the Zhongshan–Dome A traverse were drilled, and the borehole temperature was measured. Although certain problems existed pertaining to the hot-point drill, a total depth of ~244 m was successfully drilled at an average penetration rate of ~10 m h−1. After borehole drilling, ~12–15 h were generally required for the borehole to achieve thermal equilibrium with the surroundings. Preliminary results demonstrated that the 10 m snow–firn temperature along the traverse route was affected by the increasing altitude and latitude, and it decreased gradually with an increase in the distance from Zhongshan station.

The path over a surface with complex topography that a snow avalanche will take is usually not known in advance. To predict avalanche paths over such terrain, we propose a model for the motion of the mass centre of an avalanche over an arbitrary surface. The numerical solution for this model shows that avalanche paths over complex topography are very sensitive to small differences in the avalanche velocity.

The impulse radar was found to be useful in surveying the internal structures of wet snow patches in mountain regions. Radar profiles revealed that the thickness of the perennial ice was 30 m, possibly the thickest in Japan. An unconformity widely extended nearly parallel to the surface at the depth of 2 to 9 m and divided the ice into two parts.

We have conducted tests of the Canadian Land Surface Scheme (CLASS V2.5) for Arctic tundra applications. Our tests emphasize sensitivities to initial conditions, external forcings and internal parameters, and focus on the Alaskan North Slope during the summer of 1992. Observational data from the National Science foundation (NSF), Arctic Systems Science (ARCSS), Land/Atmosphere/Ice Interactions (LAII) Flux Study is available to serve as forcing and validation for our simulations.

Comparisons of the runs show strong sensitivities to the composition and depth of the soil layers, and we find that a minimum total soil depth of 5.0 m is needed to maintain permafrost. The response of the soil to diurnal variations in forcing is strong, while sensitivities to other internal parameters, as well as to precipitation, were relatively small. Some sensitivity to air temperatures and radiative fluxes, particularly the incoming shortwave flux, was also present. Significant sensitivity to the specification of the initial water and ice contents of the soil was found, while the sensitivity to initial soil temperature was somewhat less.

The water and sediment output from Vitus Lake, in Front of Bering Glacier, was monitored starting in July 1994, Instrumentation was placed in the lake outlet to record stage, turbidity, conductivity and temperature and velocity of flow of river water. Two outburst floods punctuated the termination of the 1993–94 Bering Glacier surge in August 1994. The better-documented flood lasted about 10 d, during which the flood discharge averaged 1100 m3 s−1, in excess of normal discharge (1550 m3 s−1) during this part of the ablation season, and about 9.5 × 108 m3 of water drained from Bering Glacier. The excess water volume discharged during this flood corresponds to a 0.4 m thick layer of water extending over the 2500 km2 of Bering Glacier that was surging in early summer. The suspended-sediment flux from Vitus Lake during the summer of 1994 was two orders of magnitude less than rates of sediment production by other fast-moving glaciers in southern Alaska. This implies that most of the sediment produced is being stored in Vitus Lake, under the glacier, or in both locations.

Significant upgrades to the Rapid Air Movement (RAM) Drill were developed and tested by the US Ice Drilling Program in 2016 through 2020 for the U.S. National Science Foundation. The design of the system leverages the existing infrastructure of the RAM Drill with the goal of greatly reducing the logistical burden of deploying the drill while maintaining the ability to drill an access hole in firn and ice to 100 m in 40 min or less. In this paper, characteristics of the drill are described, along with a description of the drill performance during the testing at Raven Camp in Greenland and at WAIS Divide Camp in Antarctica.

Using observations of basal topography, ice thickness and modern accumulation rates, we use theory and a dynamic flowline model to examine the sensitivity of Antarctica's Foundation Ice Stream to changes in sea level, accumulation and buttressing at the grounding line. Our sensitivity studies demonstrate that the steep, upward-sloping basal topography inland from the grounding line serves to stabilize retreat of the ice stream, while the upward-sloping submarine topography downstream from the grounding line creates the potential for significant advance under conditions of modest sea-level lowering and/or increased accumulation rate. Extrapolating from Foundation Ice Stream, many nearby Weddell Sea sector ice streams are in a similar configuration, suggesting that the historical and projected responses of this sector's ice streams may contrast with those in the Amundsen or Ross Sea sectors. This work reaffirms that the greatest concerns for rapid West Antarctic Ice Sheet (WAIS) retreat are locations of reverse slopes, muted basal topography and limited lateral support.

New results concerning the concentration of sulphate (SO4) and nitrate (NO3) in Antarctic snow and ice are presented. At Dome C, 10-year mean values and detailed studies (more than one sample a−1) were done at different depths corresponding to ages from 0 to 23 ka BP. Global volcanic activity strongly disturbs profiles of sulphate concentration for periods of a few years. Long-term fluctuations are found to be weak for both anions. The mean values obtained for acidity agree satisfactorily with the values for sulphate and nitrate. Finally, we examine the probable origin of these gas-derived aerosols in Antarctica.

A 40 km-resolution ice—ocean model of the Bering Sea is used to investigate the effects of ocean circulation and vertical convection on the seasonal and interannual ice extent variations in the Bering Sea. The model is driven with daily time-varying atmospheric forcing from 1981–83. A series of sensitivity studies is carried out to examine the effects of the vertical diffusion and precipitation on the ice margin and the effect of stratification on the ocean circulation. For comparison, an ice-only simulation, with a motionless oceanic boundary layer of fixed depth, is also carried out. In the Aleutian Basin, the ice-ocean model exhibits a cyclonic ocean circulation which consists mainly of a baroclinic current component. On the eastern Bering Sea shelf the flow is mainly barotropic, with a northwestern shelf flow along the Alaskan coast and a return southeastern flow along the shelf break. The seasonal and interannual variability of the ice margin is significantly better simulated by the ice-ocean model than by the ice-only model, especially when an enhanced vertical diffusion is used. However, the seasonal cycle of ice extent exhibits too little ice in the southeastern Bering Sea and excessive ice in the northwest. The advance and retreat of the ice edge also tends to lag behind the observed results by a few weeks. The inclusion of precipitation improves the ice extent in the southeast. The results suggest that an enhanced vertical resolution, together with a more complete boundary layer formulation, will be required to achieve realistic seasonal simulations of the Bering Sea ice–ocean system.

Atmospheric circulation patterns associated with snowfall fluctuations in Japan are examined using a rotated empirical orthogonal function (EOF) analysis. We also compute correlation coefficients between the scores of EOF modes in the 500 hPa geopotential height field of the Northern Hemisphere (NH) and amounts of snowfall in Japan on annual, monthly and pentad time scales. It is found that recent variability of snowfall amount in Japan is closely related to the long-term variations of large-scale circulation patterns. It is suggested that the dominance of teleconnection patterns such as Pacific/North American (PNA) and Northern Asian (NA) are responsible for the increase of snowfall in the coastal regions of the Sea of Japan during the cold period for Japan (1977–86).

Large-scale motions and strain-rates over great distances on polar ice sheets are often obtained from the tracking of Transit (or doppler) satellites. The results of different processing techniques for these tracking data are compared, using some of the data collected on and near Ice Stream C. Reduction is made by using the software packages CALIPER, GEODOP V, MAGNET, and the micro-processor on the Magnavox MX 1502 satellite receiver. The orbital data broadcast by the satellites are used, as well as more precise orbits obtained afterward. In addition, calculations are made for single sites individually (point positioning) and for many sites with simultaneous tracking data (network adjustment).

The results agree within the range of known errors associated with the orbits. Earth-based positions (latitude, longitude, ellipsoidal height), based on the broadcast orbits, agree to within 41.1 m. Positions with more precise orbits are within 0.7 m of one another. Relative positions are best obtained by using network techniques, and these agree with terrestrial survey results within 0.2 m in horizontal separation for sites 19 km apart, and are within 4.8 m in elevation difference. The calculated azimuth differs by 1.5 m/19 km or 10−4 rad.

An array of radio echoes has been collected on Storglaciären in Sweden and used in an aperture-synthesis experiment. The digitized echoes were combined in a computer with suitable time shifts to focus on regions beneath the ice surface. The positions of six individual englacial cavities have been found, and the echoes from them isolated for interpretation. By performing the aperture synthesis with data sets from three different antenna configurations, information on the cavity shapes and orientations has been derived. At least five of the cavities are believed to be water-filled, and may be parts of an englacial drainage system. The technique could be applied to the problem of finding the principal water channel(s) in or under a glacier. Successful location would be of considerable importance in the planning of subglacial water intakes for hydro-electric power production.

Relations between the structure and falling motion of early snowflakes, ie those composed of a few crystals, were investigated to clarify their growth process.

The following results were obtained: (1) Two crystals of the same shape in a snowflake are similar in size, but those of different shape are considerably different in size. (2) In snowflakes having two crystals of the same shape, one crystal is attached near the center of the other; where the two are of different shapes, a smaller crystal is attached near the tip of the other. (3) The nondimensional amplitude of the spiral falling motion of snowflakes composed of two crystals of different shape, is slightly larger than for those with crystals of the same shape. This suggests that snowflakes composed of different shapes are more likely to aggregate to other snowflakes or crystals. (4) In snowflakes consisting ?G three crystals, the centers are usually arranged in a straight line. (5) The nondimensional amplitude of the spiral motion of snowflakes consisting of three crystals increases with departures from the straight-line arrangement of their centers.

The Lombard Alps in the central sector of the Italian Alps are one of the most intensively glacierized regions on the southern side of the chain (about 113 km2 of ice cover). All of the glaciers have been retreating since the beginning of the 20th century, but the trend is not uniform. Since the 1950s there has been a drop in the percentage of retreating snouts and an increase in stationary and advancing snouts. After 1985 the glaciers in the Lombard Alps began a new recession phase that is still going on. This pattern is consistent with temperature variations in Lombardy in the 20th century. According to data from Sondrio station, four alternating warming and cooling phases ran be distinguished in 20th-century warming. The Lombard glaciers well recorded the last three phases, showing evident signs of the 1955–88 cold phase, with a response time of about 20 years, and may be considered good indicators of 20th-century temperature trends.

The stable oxygen isotopic composition (δ18O), texture and stratigraphy of landfast ice in Santala Bay, Gulf of Finland, were studied annually from 1999 to 2009. Apart from one year when there was no ice, maximum ice thickness ranged from 0.22 to 0.60 m. Maximum ice thickness was determined primarily by average air temperature, and a simple accumulated freezing-degree-day–ice-thickness model explained 86% of ice-thickness variance. the total ice thickness each winter was dominated by columnar ice and intermediate granular/columnar ice formed at the base of the ice cover. Meteoric ice (snow ice and superimposed ice) accumulated at the top of the ice cover each winter and constituted 4–39% of the total ice thickness (ice mass). Snow ice formed in seven of the ten winters; superimposed ice formed in only three winters. the snow fraction in the meteoric ice contributed 1–30% annually of the total ice mass, with an average of 8.8%.

A 40 km line across George VI Ice Shelf was sounded in January 1981 by both radio echo and seismic reflection methods. Because the velocities of radio and seismic waves vary with ice density in different ways, an accurate comparison of travel times from the two methods allowed the average density of the ice shelf to be calculated.

A distinguishable echo from the base of the ice shelf was recorded at 22 out of 23 seismic stations. Continuous radio echo profiling was achieved in ice varying in thickness from about 200 to 350 m. The calculated mean densities fell into two groups, In an area where summer meltwater frequently floods the surface the average densities were around 0.915 Mg m−3, while in the drier areas the average densities were around 0.884 Mg m−3. Apart from this division, there was no apparent systematic variation of average density with position. The sounding was carried out approximately along a flowline on the ice shelf.

The variation of ice density with depth and position is difficult to allow for when modelling the deformation of ice shelves. Measured values of surface strain-rate, for example, may in some circumstances need to be corrected for effects due to the compressibility of snow.

The aim of this research is to investigate elevation changes in the Antarctic ice sheet by comparing two digital elevation models (DEMs) derived from satellite altimetry data covering the period 1994–2004. Data collected by ERS-1/2 satellite radar altimetry and by NASA GLAS/ICESat laser altimetry were used. After preprocessing and resampling at the same spatial resolution, both DEMs were compared in a pointwise fashion and elevation differences computed, which consisted of three main components: (1) actual elevation change, (2) errors in the original data sources and (3) interpolation errors that arose during generation of the DEMs. The objectives of the research were to analyze errors, attempt to mitigate systematic effects when possible, and draw some conclusions about the limitations of using DEM products for computing ice-sheet elevation change at local and continental scales. A linear correlation between errors in elevation differences and surface slope was found in the slope range [0°, 0.4°]. This trend was interpreted as residual slope-induced systematic error and compensated for. Finally, an elevation difference map of the Antarctic ice sheet was generated. Analysis of the derived elevation changes at the drainage basin was also made. Results are compared with the results of previous studies.