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The article discusses a study which reported density profiles gathered at 46 survey sites, from coastal to inland plateau regions in East Antarctica. Research groups from Japan and Sweden carried out a traverse expedition in East Antarctica, between the Japanese inland base S16 and the Swedish Wasa station, from November 2007 to January 2008. Snow measurements were conducted on a side-wall of a snow pit excavated at each survey site. The snow structure was classified into fresh snow, compacted snow, faceted crystals or depth hoar, and a crust layer.

Abstract: We present the results of an Antarctic spring field study of snow drift threshold measurements made using two custom drift sensors and a commercial parts-counting device. All three sensor types worked well at detecting drifting snow events, but the sensors recorded different magnitudes (particle count per unit time) of drift. Each sensor has a unique detection threshold for particle size, and responded differently to identical wind and snow conditions, although the particle counts from the different sensors are linearly related at low wind speeds. The drift threshold is defined here as the minimum friction velocity at which drifting snow was observed during more than 10% of measurements at that wind speed. The results of this multi-sensor study demonstrate that the drift threshold is lower (friction velocity of 0.2m/s) for very small particles that are likely transported in suspension than for coarse-grained saltating particles (0.25m/s). These friction velocities correspond to 10-meter wind speeds of 5.6 and 7.2m/s respectively for the conditions during this experiment. The commercially available parts counter is recommended as a low-cost alternative to custom-built drift sensors for use in future field studies of drifting and blowing snow. [Copyright &y& Elsevier]

The article presents a study which examines the vertical profile of the snow's specific surface area (SSA) and density at Dome C and Dumont D'Urville in Antarctica. The study assesses the infrared (IR) reflectance of snow at 1310 nanometers using the dual-frequency integrating sphere for snow (DUFISS) system. It is found out that the vertical profile of SSA and density can be used in calculating the spectral albedo of the snow for several illumination conditions.

Abstract: The Sea Ice Mass Balance in the Antarctic (SIMBA) experiment was conducted from the RVIB N.B. Palmer in September and October 2007 in the Bellingshausen Sea in an area recently experiencing considerable changes in both climate and sea ice cover. Snow and ice properties were observed at 3 short-term stations and a 27-day drift station (Ice Station Belgica, ISB) during the winter–spring transition. Repeat measurements were performed on sea ice and snow cover at 5 ISB sites, each having different physical characteristics, with mean ice (snow) thicknesses varying from 0.6m (0.1m) to 2.3m (0.7m). Ice cores retrieved every five days from 2 sites and measured for physical, biological, and chemical properties. Three ice mass-balance buoys (IMBs) provided continuous records of snow and ice thickness and temperature. Meteorological conditions changed from warm fronts with high winds and precipitation followed by cold and calm periods through four cycles during ISB. The snow cover regulated temperature flux and controlled the physical regime in which sea ice morphology changed. Level thin ice areas had little snow accumulation and experienced greater thermal fluctuations resulting in brine salinity and volume changes, and winter maximum thermodynamic growth of ∼0.6m in this region. Flooding and snow–ice formation occurred during cold spells in ice and snow of intermediate thickness. In contrast, little snow–ice formed in flooded areas with thicker ice and snow cover, instead nearly isothermal, highly permeable ice persisted. In spring, short-lived cold air episodes did not effectively penetrate the sea ice nor overcome the effect of ocean heat flux, thus favoring net ice thinning from bottom melt over ice thickening from snow–ice growth, in all cases. These warm ice conditions were consistent with regional remote sensing observations of earlier ice breakup and a shorter sea ice season, more recently observed in the Bellingshausen Sea. [Copyright &y& Elsevier]

Abstract: In the marginal sea ice zone (MIZ), where relatively small ice floes are dominant, the floe size distribution is an important parameter affecting melt processes given the larger cumulative perimeter of multiple small floes compared with a single ice floe of the same area. Smaller ice floes are therefore subject to increased lateral melt. However, the available data have been very limited so far. Analysis of sea ice in the Sea of Okhotsk revealed that while floe size distribution is basically scale invariant, a regime shift occurs at a size of about 40m. In order to extend this preliminary result to the Antarctic MIZ and further examine the controlling factors, the first concurrent ice floe size and ice thickness measurements were conducted in the northwestern Weddell Sea and off Wilkes Land (around 64°S, 117°E) with a heli-borne digital video camera in the late winter of 2006 and 2007, respectively. The floe sizes ranged from 2 to 100m. Our analysis shows: 1) the scale invariance and regime shift are confirmed in both regions; 2) the floe size at which regime shift occurs slightly increases from 20 to 40m, with ice thickness, consistent with the theory of the flexural failure of sea ice; and 3) the aspect ratio is 1.6-1.9 on average, close to the previous results. Based on these results, the processes affecting the floe size distribution and the subsequent implications on melt processes are discussed. By applying a renormalization group method to interpret the scale invariance in floe size distribution, the fractal dimension is related to the fragility of sea ice. These results indicate the importance of wave-ice interaction in determining the floe size distribution. [Copyright &y& Elsevier]

The article examines the composition, structure and deformation of amber ice as well as its influence on Rhone Glacier's behaviour in the McMurdo Dry Valleys in Antarctica. The basal ice sequence of the cold-based glacier was investigated using isotopic and solute chemistry data. The study identifies three different ice facies including englacial, amber and stratified. The analysis of stratified facies shows an isotopic signature which indicates melt then refreeze processes and is most likely associated with apron entrainment. It was found out that impurities in the amber ice has prolonged contact with the bed and that depleted isotopic signature is consistent with ice formed during a cooler period.

Abstract: We investigated the single scattering optical properties of snow for different ice particle shapes and degrees of microscopic scale roughness. These optical properties were implemented and tested in a coupled atmosphere-snow radiative transfer model. The modeled surface spectral albedo and radiance distribution were compared with surface measurements. The results show that the reflected radiance and irradiance over snow are sensitive to the snow grain size and its vertical profile. When inhomogeneity of the particle size distribution in the vertical is taken into account, the measured spectral albedo can be matched, regardless of the particle shapes. But this is not true for the modeled radiance distribution, which depends a lot on the particle shape. The usual “equivalent spheres” assumption significantly overestimates forward reflected radiances, and underestimates backscattering radiances, around the principal plane. On average, the aggregate shape assumption has the best agreement with the measured radiances to a mean bias within 2%. The snow optical properties with the aggregate assumption were applied to the retrieval of snow grain size over the Antarctic plateau. The retrieved grain sizes of the top layer showed similar and large seasonal variation in all years, but only small year to year variation. Using the retrieved snow grain sizes, the modeled spectral and broadband radiances showed good agreements with MODIS and CERES measurements over the Antarctic plateau. Except for the MODIS 2.13 μm channel, the mean relative model-observation differences are within few percent. The modeled MODIS radiances using measured surface reflectance at Dome C also showed good agreement in visible channels, where radiation is not sensitive to snow grain size and the measured surface bidirectional reflectance is applicable over the Antarctic plateau. But modeled radiances using local, surface-measured reflectance in the near infrared yielded large errors because of the high sensitivity to the snow grain size, which varies spatially and temporally. The CERES broadband shortwave radiance is moderately sensitive to the snow grain size, comparable to the MODIS 0.86 μm channel. The variation of broadband snow reflectance due to the seasonal variation in snow grain size is about 5% in a year over the Antarctic plateau. CERES broadband radiances simulated with grain sizes retrieved using MODIS are about 2% larger than those observed. [Copyright &y& Elsevier]

The article focuses on the two parameters, near-surface temperature and snowfall variability, that will help in understanding the contribution of Antarctica to the global climate change and sea level rise. Antarctica is a region studied by most researchers due to its geographic remoteness, extreme climate, and lack of human inhabitants. Researchers focus on its climate records, to assess its regional changes. A research, adopting the techniques of temperature and snowfall variability, was conducted to know if the Antarctic climate change has an impact on global climates. An overview of the temperature and snowfall variability, applied on Antarctica, is offered. Meanwhile, furtherance on researches on Antarctica's climate records are still recommended to position it under global perspective.

Presents research which studied the average elevation of the Antarctic Ice Sheet from 1992 to 1996. Use of satellite radar altimeter measurements; Variability of snowfall; Mass imbalance of the interior this century compared with the mean mass accumulation rate.