A method for calculating the impulse response of a layered dielectric is used to investigate the effect of near-surface density stratification on the interpretation of radar-altimetry data collected over ice sheets. Results are computed for a model consisting of a measured density profile that is artificially interrupted by an ice layer inserted at successively greater depths. The incident radar signal is modeled by a 20 ns long pulse modulated at 1 GHz. Analysis using a simple scheme for estimating the one-way travel time of the wave indicates as much as a 2 ns (equivalent to 60 cm in range) apparent time delay for a density profile that has been modified by inclusion of an ice layer relative to the ice-layer-free case. This suggests that layering may be a factor in interpreting repeated altimeter measurements of the ice sheets in terms of net growth or decay.

To identify the regional characteristics of mountain snowpacks related to avalanches in the central mountains of Japan, snow-pit observations were carried out over a period of between two and five winters at six study sites in three major mountain ranges: the north, central and south alps. The relationship between snowpack characteristics and meteorological properties was then examined to suggest indicators that could determine the snowpack characteristics in the region using meteorological data. On the basis of the dominant type of persistent weakness found within snowpacks, the study sites were divided into three regions: (1) the mountains on the Sea of Japan side - the persistent weakness was caused mainly by the presence of melt-freeze crust (MFcr) layers; (2) the inland mountains - the persistent weakness was caused mainly by the presence of weak layers consisting of near-surface faceted crystals (FCsf); and (3) the mountains on the Pacific Ocean side - the persistent weakness was caused mainly by the formation of thick weak layers consisting of depth hoar (DH) near the ground. The results also suggest that certain meteorological elements are useful indicators of the tendency of a persistent weakness to form within the snowpack: (1) DH layers: TG (°C m−1) = |average air temperature |/average snow depth (notable weakness in DH layers is found in areas where the TG exceeds 10°C m−1, but in such areas rainfall prevents the development of DH layers); (2) FCsf layers: FCsf index (CC m) = average diurnal range of air temperature × snow depth (notable weakness in FCsf layers is found in areas where the FCsf index is ∼10°C m); (3) MFcr layers: MFcr index (day m) = number of days that exceed 0°C × snow depth (notable weakness in MFcr layers is found in areas where the MFcr index exceeds 40 day m).

The shift of the equilibrium line in response to climatic disturbances is calculated for the International Glaciological Greenland Expedition (EGIG) profile of the Greenland Ice Cap. Data of heat balance studies carried out during EGIG 1959 and EGIG 1967 are used according to Kuhn’s algorithm. The following parameters are applied; the heat transfer coefficient of the sensible heat flux; the effective emissivity of the atmosphere for long wave downward radiation; a factor relating net radiation to cloudiness; the duration of the ablation season; the altitudinal temperature gradient; the altitudinal accumulation gradient.

The altitudinal shift of the equilibrium line results for the EGIG profile + 77m/°C and -4 m per 1/10 cloudiness with 35d of ablation. Changes in heat balance by formation of superimposed ice are taken into account.

The salinity and isotope (18O, 3H) content of multi-year landfast sea-ice (MLSI) cores from northern Ellesmere Island, Canada, are examined. Salinity ranges from 0.01‰ to 4.54‰, and δ18O ranges from −23.8‰ to +0.7‰. Salinity and δ18O are linearly related, and tritium values generally exceed natural background levels. The results are evidence of ice growth associated with fresh-water / sea-water stratification below the ice. Salinity variations are cyclic and indicate a mean annual bottom accretion rate of 0.33–0.5 m a−1. Rather than signifying downward percolation of melt water from the surface, the ice δ values are a proxy measure of variations in salinity and 18O content of the water below the ice. Annual salinity layers are preserved in the absence of significant brine movement and ice deformation. The fast-ice environment appears to favour the maintenance of water stratification and growth of annual layers. It is suggested that ice growth in this environment is somewhat independent of thermodynamic sea-ice growth models; instead, ice growth by a double-diffusion process might account for the growth of MLSI beyond thicknesses normally encountered in undeformed multi-year pack-ice floes.

The inventory of Glacier National Park, B.C., has provided an opportunity to test a number of new procedures which might be applied to future Canadian glacier inventories. The objectives of this particular study were to complete a tripartite inventory based on available map and photo sources and develop an automated system of data acquisition and processing. The conjunction of the two has permitted an analysis of the evolution of the glaciers in this area during the last 100 years. The techniques used and a summary of the results are reported.

Source areas of snow-melt run-off vary spatially and temporally, with corresponding changes in chemistry of the snow-pack, and influence both timing and quality of snow-pack run-off. In the the alpine basin of Emerald Lake, located in the southern Sierra Nevada, California, U.S.A., we have found that nitrate ion and sulphate ion concentrations in streams were correlated with the amount of snow melt in each sub-basin. Inflows to Emerald Lake had elevated concentrations of , and , which corresponded temporally with the initiation of snow melt in each sub-basin. Concentrations of both anions then decreased as snow melt progressed. The onset of snow melt shifted temporally from sub-basins with a south-westerly aspect to basins with a progressively more northerly aspect. The and pulses also moved, with time, from the sub-basins with south-westerly aspects to those with more northerly aspects. The time span over which the basin experienced these anionic pulses was longer than that for any single sub-basin. Maximum concentrations of and in the lake outflow, which also occurred at the onset of snow melt, were elevated by 100 and 40%, respectively, above their January concentrations in line with increases in inflow, but were sustained for a longer period than that of any inflow increase.

Antarctic researches of the last decades have provided new facts which have made scientists change their ideas. The researches have shown a great difference between the history of the Antarctic and the northern hemisphere glaciation. The former is very old and stable, while the latter was ephemeral. An analogous one to the Antarctic ice sheet in the northern hemisphere is the Greenland inland ice. Both ice sheets are of continental-insular type; the Pleistocene ice sheets were of continental type proper. Icethickness measurements showed the topography of the bed under Antarctic ice and revealed a special type of ice sheet lying partly on the sea-floor: the West Antarctic continental-marine ice sheet. Such ice sheets could exist in the northern hemisphere too. They were especially unstable and their formation and destruction could serve as a triggering mechanism in alternating glacials and interglacials. The main concept is: all the great climatic variations during the Pleistocene were glacioclimatic ones where the feedback mechanism was the most important factor. But there are many details which are uncertain. The Antarctic and Greenland ice sheets are the key regions to research so that problems of glacioclimatology could be solved.

The purpose of this study is to identify characterize and quantify local, regional and remote effects of snow cover on western U. S. climate and water resources. An ensemble of predictability and sensitivity studies was made with the U.S. National Center for Atmospheric Research (NCAR) Community Climate Model, version 3 (CCM3) to investigate the relative roles of snow-cover anomalies and initial atmospheric states in the subsequent accumulation and ablation seasons. The suite of model experiments focuses on the direct effect of snow on regional climate anomalies and ultimately will be used to examine the lagged effect of anomalous snow cover on the climate. The set of ensemble simulations presented here looks at the climate-system response to anomalously high and low snow cover at the start of the ablation season over the western U.S.A. These current results suggest that the initial state of snow cover is more important than the initial state of the atmosphere or of sea-surface temperatures because of direct thermal effects on the surface and subsequent indirect, dynamical effects on the atmospheric circulation.

Monitoring the tension in cables is significant in some ice drill and deepwater applications. Take our RECoverable Autonomous Sonde (RECAS) for example. It is able to melt a hole to the bottom of ice sheet and is able to move upwards. A winch is installed inside RECAS to release and recover the cable, whose tension needs to be monitored in real time in order to control the behavior of the winch. The high pressure of deep water and limited installation space pose great challenges in sensor development. In this paper, two editions of newly designed deepwater tension sensors are proposed. The first edition is based on a fresh hydraulic load module that operates in high pressure environment and the second edition tension, which aims to improve the accuracy, applies a newly designed watertight load module. Detailed force transmission and characteristic analysis of the sensors are carried out. The sensors have got through a series of experiments, including calibration experiments, pressure experiments and field experiments. The resultant accuracy of the second edition sensor, which has a better performance, is over 2% under the measuring range of 1000 kg and the dimension of the final sensor is as compact as 150 mm × 137 mm × 86 mm.

Relationships between stable isotopes (δD–δ18O), ice facies and glacier structures have hitherto gone untested in the mid-latitude maritime glaciers of the Southern Hemisphere. Here, we present δD–δ18O values as part of a broader study of the structural glaciology of Fox Glacier, New Zealand. We analyzed 94 samples of δD–δ18O from a range of ice facies to investigate whether isotopes have potential for structural glaciological studies of a rapidly deforming glacier. The δD–δ18O measurements were aided by structural mapping and imagery from terminus time-lapse cameras. The current retreat phase was preceded by an advance of 1 km between 1984 and 2009, with the isotopic sampling and analysis undertaken at the end of that advance (2010/11). Stable isotopes from debris-bearing shear planes near the terminus, interpreted as thrust faults, are isotopically enriched compared with the surrounding ice. When plotted on co-isotopic diagrams (δD–δ18O), ice sampled from the shear planes appears to show a subtle, but distinctive isotopic signal compared with the surrounding clean ice on the lower glacier. Hence, stable isotopes (δD–δ18O) have potential within the structural glaciology field, but larger sample numbers than reported here may be required to establish isotopic contrasts between a broad range of ice facies and glacier structures.

Cosmogenic nuclide measurements in glacial deposits extend our knowledge of glacier chronologies beyond the observational record. The short half-life of in situ cosmogenic 14C makes it particularly useful for studying glacier chronologies, as resulting exposure ages are less sensitive to nuclide inheritance when compared with more commonly measured, long-lived nuclides. An increasing number of laboratories using an automated process to extract carbon from quartz has led to in situ 14C measurements in Antarctic samples at an accelerating rate over the past decade, shedding light on deglaciation in Antarctica. In situ 14C has had the greatest impact in the Weddell Sea Embayment, where inferences on the thickness of ice and timing of deglaciation were limited by inheritance in other cosmogenic nuclide systems. Future subglacial measurements of the nuclide hold much potential as they can provide direct evidence of proposed Holocene thinning and subsequent re-thickening of parts of the Antarctic ice sheets.

Significant salinity anomalies have been observed in the Arctic Ocean surface layer during the last decade. Our study is based on an extensive gridded dataset of winter salinity in the upper 50 m layer of the Arctic Ocean for the periods 1950–1993 and 2007–2012, obtained from ~20 000 profiles. We investigate the interannual variability of the salinity fields, identify predominant patterns of anomalous behavior and leading modes of variability, and develop a statistical model for the prediction of surface-layer salinity. The statistical model is based on linear regression equations linking the principal components of surface-layer salinity obtained through empirical orthogonal function decomposition with environmental factors, such as atmospheric circulation, river runoff, ice processes and water exchange with neighboring oceans. Using this model, we obtain prognostic fields of the surface-layer salinity for the winter period 2013–2014. The prognostic fields generated by the model show tendencies of surface-layer salinification, which were also observed in previous years. Although the used data are proprietary and have gaps, they provide the most spatiotemporally detailed observational resource for studying multidecadal variations in basin-wide Arctic salinity. Thus, there is community value in the identification, dissemination and modeling of the principal modes of variability in this salinity record.

Results of measurements performed on and around an Antarctic blue-ice field are presented in this paper. The measurements were carried out in a valley of Heimefrontfjella, Dronning Maud Land, during a 2 month field season in the austral summer of 1992–93. A simple model is used to evaluate the surface-energy balance from measured meteorological quantities. The large differences in the surface-energy-balance values between snow and blue ice are mainly caused by differences inalbedo, surface roughness, thermal conductivity and short-wave radiation extinction coefficient. Taking into account uncertainties in the calculations, it appears that the calculated sublimation rates over ice and snow do not differ much.

Furthermore, typical circulation patterns are described. The large continental-scale katabatic flow is forced by radiative cooling of the surface (night-time) and the mesoscale horizontal temperature gradient (daytime). The latter penetrates to the surface due to enhanced mixing in an unstable stratified boundary layer. At night, shallow katabatic layers form along local fall lines. On some occasions the large-scale katabatic winds decrease through the presence of a high-pressure system in the weddell Sea and a local circulation can develop inside the valley.

Ionic analyses of snow samples collected from snow pits and cores, and samples of meltwater collected from the only river draining the Norwegian glacier Austre Okstindbreen during the 1995 summer, showed that the input/output relations of sodium and chloride were nearly identical. Sampling at the pits revealed that some 72% of the Na+ and Cl– ions which accumulated in winter drained from the snowpack in early June with the first 12% of the meltwater. Concentrations and loads of the two ions in the first meltwater draining from the glacier in late May were relatively high. There then followed a slight decrease in both the concentrations and the loads of the two ions in samples of the river water, and more-or-less steady levels were present for a long period. In late July, concentrations decreased. Loads decreased in early August, indicating that most of the winter-accumulated ions had drained from the catchment. Input and output calculations for Na+ and C1– indicate a total drainage time for the first meltwater from the uppermost part of the accumulation area of 6–7 weeks, equivalent to an average drainage velocity of 100 md–1.

The Glacial Geomorphological Map (1:200 000) of Mt, Tomur Region, Tianshan, covers 78°33′ – 81°10′E and 41° 08′ – 42° 44′N, with high mountains, deep valleys and many snow peaks, the highest being Mt. Tomur (7435.3 a.s.l.). There are many glaciers in this region with a total area of 4553.69 km2. The melt water from glaciers irrigates the large oasis of Aksu, in the piedmont region in southern Xingjiang and waters the valley plain of Teks River in the Yili area. From piedmont plain to highest mountain summit, the vertical zonality of geomorphology is quite clear, rich in various geomorphological types, representing alpine geomorphology of the arid desert in Central Asia.

The author joined the glacial/geomorphological expedition to the Mt. Tomur Region in 1963, 1973 and 1974, and, in the process of mapping, cooperated closely with mapping engineers. This involved extensive use of aerial photographs, satellite images, large-scale topographic maps, geological maps, geomorphological maps and other data, and comprehensive analyses, comparisons, and judgements of data.

Special emphasis was placed on existing glaciers and the geomorphology of Quaternary glaciers, according to form, composition and relative chronological periods. The geomorphology was divided into five great systems, i.e. glacial, fluvio-glacial, fluvial, arid and artificial. Twenty-four geomorphic types were defined as the basic elements of the geomorphological map and shown in different colours and by various marks, while old and Neozoic faults were shown by black line marks. There are representative heights on all geomorphological zones. Colour brush-shading added much to the stereo effect.

Below the main map, the longitudinal and cross sections of Quaternary geology and geomorphology of the Tialan valley, the stratigraphical columnar profile of West Zamtia and the fluvial/lacustrine deposit profile of the Loska basin were attached, showing the stratigraphical relation between the glacial and non-glacial deposit and the basis for the divisions of the glacial and inter-glacial periods.

To study crystal shapes, and formation and growth mechanisms of snow crystals formed below -20 °C, a new type of diffusion chamber was constructed. Using this chamber, different kinds of “peculiar shaped” crystals previously observed in nature have been produced, together with normal types of snow crystals. Gohei twins, one of the most typical polycrystalline shapes in nature, have been produced artificially. The vapor pressure was at or near water saturation at the time of nucleation. Analysis of photomicrographs and replicas of Gohei twins that were replicated in the polar regions show that the number frequency of the tip angle has a maximum frequency at about 77° and a minor one at about 54°.

On the basis of these results, a formation mechanism for some Gohei twins is proposed in this paper.

Data from twice-daily radiosonde flights are used to estimate spatial and temporal variations of air temperature, atmospheric transmissivity, wind speed and humidity at Blue Glacier, western Washington. U. S.A. Results indicate that the free-air conditions (interpolated in altitude and in time from radiosondes) provide a much better estimate of conditions on the glacier than do measurements from low-altitude stations. Data from the radiosondes are used to model the hourly exchange of mass and energy at the surface of Blue Glacier. In the absence of explicit information about clouds, temperature and humidity profiles from the radiosonde are used to estimate the atmospheric transmissivity needed for the calculation of short-wave radiation. Topographical influences (altitude, shading, slope angle and orientation) and surface albedo are parameterized explicitly to model the absorbed solar flux at specific sites on the glacier, Other energy fluxes (long-wave radiation, sensible-heat and latent-heat exchange) are estimated using established physical models. Hourly estimates of ablation are integrated to obtain the seasonal ablation. Modeled ablation and stake measurements made over 30 a at two sites on Blue Glacier agree within 16%, which is within the error associated with stake measurements of ablation.

In this paper we present a new methodology for the study of drifting-snow phenomena at an Alpine site This method emphasizes the accurate determination of local wind directions and the distribution of snow denudation and accumulation zones through the observation, measurement and mapping of aeolian “snowforms” and drifts. The aim is to find out whether the local wind directions on extensive surfaces in mountain areas (of about a few km2) are independent of the main wind intensity and direction, and whether valid erosion and accumulation zones are spatially stable and can be established for dominant winds. The methodology proposed to study the spatial distribution of snow by the wind has been used in the redesign of an old ski slope at La Molina, a resort in the eastern Spanish Pyrenees. Results have been very useful for deciding the design of the slopes. Therefore, we believe that the prediction of spatial snow distribution by wind in mountain areas, without the need for expensive instruments, has a valuable part to play in the management of mountain and ski resorts and roads, and in avalanche forecasting.

Monitoring ice motion provides insight into the relative contributions of atmospheric and oceanic forcing to polynya dynamics In this study ice kinematics in the North Water (NOW) region, northern Baffin Bay Canadian Arctic are determined using time-sequential RADARSAT-1 ScanSARWide imagery (from the period January-December 1998), processed by the automated ice-tracking algorithm (Tracker) currently used at the Canadian Ice Service (CIS). A case-study is then carried out on the Smith Sound region from January till the end of june 1998 to monitor polynya formation, maintenance and disintegration. This has two objectives: (1) to evaluate satellite ice-motion products as a means of better understanding the relative contributions of latent- and sensible-heat mechanisms responsible for the formation and behaviour of the NOW polynya, and (2) to study the influence of winds on regional sea-ice motion. Derived ice-motion maps were validated using in situ ice beacons deployed onto floes in the NOW region during the 1998 ship-based science experiment. Tracker-derived displacement and directional regressions were 0.93 and 0.79, respectively, with a total standard error of 3.6 km in magnitude and 38.8° in direction. Analysis of monthly mean ice-motion maps shows that a significant export of ice occurs from the polynya. A comparison of weekly-averaged ice motion with the mean wind-field data suggests that ice export in Smith Sound is influenced by synoptic-scale atmospheric pressure systems.