Changes in the timing and duration of the near-surface soil freeze/thaw status from 1956 to 2006 across China
The Cryosphere, 9, 1321-1331, doi:10.5194/tc-9-1321-2015, 2015
A ground temperature map of the North Atlantic permafrost region based on remote sensing and reanalysis data
Summary: We use remotely sensed land surface temperature and land cover in conjunction with air temperature and snowfall from a reanalysis product as input for a simple permafrost model. The scheme is applied to the permafrost regions bordering the North Atlantic. A comparison with ground temperatures in boreholes suggests a modeling accuracy of 2 to 2.5 °C.
The Cryosphere, 9, 1303-1319, doi:10.5194/tc-9-1303-2015, 2015
Parameterization of single-scattering properties of snow
Summary: While snow grains are distinctly non-spherical, spheres are often assumed in radiative transfer calculations. Here, angular scattering measurements for blowing snow are used to select an optically equivalent snow grain shape model. Parameterizations are then developed for the asymmetry parameter, single-scattering co-albedo and phase function of snow. The parameterizations will help to improve the treatment of snow in radiative transfer applications, including remote sensing and climate models.
The Cryosphere, 9, 1277-1301, doi:10.5194/tc-9-1277-2015, 2015
Automatic monitoring of the effective thermal conductivity of snow in a low-Arctic shrub tundra
Summary: The thermal conductivity of Arctic snow strongly impacts ground temperature, nutrient recycling and vegetation growth. We have monitored the thermal conductivity of snow in low-Arctic shrub tundra for two consecutive winters using heated needle probes. We observe very different thermal conductivity evolutions in both winters studied, with more extensive melting in the second winter. Results illustrate the effect of vegetation on snow properties and the need to include it in snow physics models.
The Cryosphere, 9, 1265-1276, doi:10.5194/tc-9-1265-2015, 2015
Theoretical analysis of errors when estimating snow distribution through point measurements
Summary: In this article, we present a methodology for the objective evaluation of the error in capturing mean snow depths from point measurements. We demonstrate, using LIDAR snow depths, how the model can be used for assisting the design of survey strategies such that the error is minimized or an estimation threshold is achieved. Furthermore, the model can be extended to other spatially distributed snow variables (e.g., SWE) whose statistical properties are comparable to those of snow depth.
The Cryosphere, 9, 1249-1264, doi:10.5194/tc-9-1249-2015, 2015
Weak precipitation, warm winters and springs impact glaciers of south slopes of Mt. Everest (central Himalaya) in the last 2 decades (1994–2013)
Summary: Climate-trends data in Himalaya are completely absent at high elevation. We explore the south slopes of Mt Everest though time series reconstructed from 7 stations (2660-5600m) during 1994-2013. The main increase in temp is concentrated outside of the monsoon, minimum temp increased far more than maximum, while we note a precipitation weakening. We contribute to change the perspective on which climatic drivers (temperature vs. precipitation) led mainly the glacier responses in the last 20 yr.
The Cryosphere, 9, 1229-1247, doi:10.5194/tc-9-1229-2015, 2015
Brief Communication: Newly developing rift in Larsen C Ice Shelf presents significant risk to stability
Summary: Within the last year, a large rift in the southern part of the Larsen C Ice Shelf, Antarctic Peninsula, propagated towards the inner part of the ice shelf. In this study we present the development of the rift as derived from remote sensing data and assess the impact of possible calving scenarios on the future stability of the Larsen C Ice Shelf, using a numerical model. We find that the calving front is likely to become unstable after the anticipated calving events.
The Cryosphere, 9, 1223-1227, doi:10.5194/tc-9-1223-2015, 2015
Dramatic loss of glacier accumulation area on the Tibetan Plateau revealed by ice core tritium and mercury records
The Cryosphere, 9, 1213-1222, doi:10.5194/tc-9-1213-2015, 2015
Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming
Summary: This paper presents an assessment of changes in the near-surface structure of the accumulation zone of the Greenland Ice Sheet caused by an increase of melt at higher elevations in the last decade, especially during the unusually warm years of 2010 and 2012. The increase in melt and firn densification complicate the interpretation of changes in the ice volume, and the observed increase in firn ice content may reduce the important meltwater buffering capacity of the Greenland Ice Sheet.
The Cryosphere, 9, 1203-1211, doi:10.5194/tc-9-1203-2015, 2015
User requirements for the snow and land ice services – CryoLand
Summary: The paper provides detailed information on the outcome of a user survey carried out in the EU FP7 project CryoLand. The project focuses on monitoring of seasonal snow, glaciers and lake/river ice. The user survey showed that a European operational snow and land ice service is required and that there exists products that can meet the specific needs. The majority of the users were mainly interested in the snow services, but also the lake/river ice products and the glacier products were desired.
The Cryosphere, 9, 1191-1202, doi:10.5194/tc-9-1191-2015, 2015
Winter speed-up of quiescent surge-type glaciers in Yukon, Canada
Summary: Whereas glacier surge is known to often initiate in winter, we show significant winter speed-up signals in the upstream region even at quiescent surge-type glaciers in Yukon, Canada. Moreover, the winter speed-up region expanded from upstream to downstream. Given the absence of surface meltwater input in winter, we speculate the presence of englacial water storage that does not directly connect to the surface, yet can promote basal sliding through increased water pressure.
The Cryosphere, 9, 1183-1190, doi:10.5194/tc-9-1183-2015, 2015
Evolution of ice-shelf channels in Antarctic ice shelves
Summary: Floating ice shelves extend the continental ice of Antarctica seawards and mediate ice-ocean interactions. Many ice shelves are incised with channels where basal melting is enhanced. With data and modeling it is shown how the channel geometry depends on basal melting and along-flow advection (also for channels which are not freely floating), and how channel formation imprints the general flow pattern. This opens up the opportunity to map the channel formation from surface velocities only.
The Cryosphere, 9, 1169-1181, doi:10.5194/tc-9-1169-2015, 2015
Snowfall in the Himalayas: an uncertain future from a little-known past
Summary: Snow and ice provide large amounts of meltwater to the Indus, Ganges and Brahmaputra rivers. In this study we show that climate change will reduce the amount of snow falling in the Himalayas, Hindu Kush and Karakoram substantially. The limited number of observations in remote upper-level terrain makes it difficult to get a complete overview of the situation today, but our results indicate that by 2071–2100 snowfall may be reduced by 30–70% with the strongest anthropogenic forcing scenario.
The Cryosphere, 9, 1147-1167, doi:10.5194/tc-9-1147-2015, 2015
Air temperature variability over three glaciers in the Ortles–Cevedale (Italian Alps): effects of glacier fragmentation, comparison of calculation methods, and impacts on mass balance modeling
Summary: Using a dataset from 12 weather stations collected in 2010 and 2011, we analyzed the air temperature variability and wind regime over three different glaciers in the Ortles-Cevedale. The magnitude of the cooling effect and the occurrence of katabatic boundary layer processes showed remarkable differences among the three ice bodies, suggesting the likely existence of important reinforcing mechanisms during glacier decay and fragmentation, with significant impacts for glacier mass balance modeling.
The Cryosphere, 9, 1129-1146, doi:10.5194/tc-9-1129-2015, 2015
Modelling glacier change in the Everest region, Nepal Himalaya
Summary: A glacier mass balance and redistribution model that integrates field observations and downscaled climate fields is developed to examine glacier sensitivity to future climate in the Everest region of Nepal. The modelled sensitivity of glaciers to future climate change is high, and glacier mass loss is sustained through the 21st century for both middle- and high-emission scenarios. Projected temperature increases will expose large glacier areas to melt and reduce snow accumulations.
The Cryosphere, 9, 1105-1128, doi:10.5194/tc-9-1105-2015, 2015
Constraints on the δ2H diffusion rate in firn from field measurements at Summit, Greenland
Summary: We performed 2H isotope diffusion measurements in the upper 3 metres of firn at Summit, Greenland, by following over a 4-year period isotope-enriched snow that we deposited. We found that the diffusion process was much less rapid than in the most commonly used model. We discuss several aspects of the diffusion process that are still poorly constrained and might lead to this discrepancy. Quantitative knowledge of diffusion is necessary for use of the diffusion process itself as a climate proxy.
The Cryosphere, 9, 1089-1103, doi:10.5194/tc-9-1089-2015, 2015
Unlocking annual firn layer water equivalents from ground-penetrating radar data on an Alpine glacier
Summary: This study presents a method for estimating annual accumulation rates on a temperate Alpine glacier based on the interpretation of internal reflection horizons in helicopter-borne ground-penetrating radar (GPR) data. In combination with a simple model for firn densification and refreezing of meltwater, GPR can be used not only to complement existing mass balance monitoring programmes but also to retrospectively extend newly initiated time series.
The Cryosphere, 9, 1075-1087, doi:10.5194/tc-9-1075-2015, 2015
Thin-ice dynamics and ice production in the Storfjorden polynya for winter seasons 2002/2003–2013/2014 using MODIS thermal infrared imagery
Summary: The Storfjorden polynya (Svalbard) forms regularly under the influence of strong north-easterly winds. In this study, spatial and temporal characteristics for the period 2002/03-2013/14 were inferred from daily calculated thin-ice thickness distributions, based on MODIS ice surface temperatures and ERA-interim reanalysis. With an estimated average ice production of 28.3km³/winter, this polynya system is of particular interest regarding its potential contribution to deep water formation.
The Cryosphere, 9, 1063-1073, doi:10.5194/tc-9-1063-2015, 2015
Ice-dynamic projections of the Greenland ice sheet in response to atmospheric and oceanic warming
The Cryosphere, 9, 1039-1062, doi:10.5194/tc-9-1039-2015, 2015
The influence of surface characteristics, topography and continentality on mountain permafrost in British Columbia
Summary: In this paper we describe surface and thermal offsets derived from distributed measurements at seven field sites in British Columbia. Key findings are i) a small variation of the surface offsets between surface types; ii) small thermal offsets at all sites; iii) a clear influence of the micro-topography due to snow cover effects; iv) a north--south difference of the surface offset of 4°C in vertical bedrock and of 1.5–-3°C on open gentle slopes; v) only small macroclimatic differences.
The Cryosphere, 9, 1025-1038, doi:10.5194/tc-9-1025-2015, 2015