Brief communication: Candidate sites of 1.5 Myr old ice 37 km southwest of the Dome C summit, East Antarctica The Cryosphere DOI 10.5194/tc-12-2167-2018 28 June 2018 Locating a suitable drill site is a key step in the Antarctic oldest-ice challenge. Here we have conducted a 3-D ice flow simulation in the region of Dome C using a refined bedrock description. Five selection criteria are computed that together provide an objective overview on the local ice flow conditions. We delineate kilometer-scale favorable areas that overlap with the ones recently proposed by another group. We propose a few drill sites that should be surveyed during the next field seasons. Read more
Snow depth on Arctic sea ice from historical in situ data The Cryosphere DOI 10.5194/tc-12-1867-2018 5 June 2018 In this paper we analyze snow data from Soviet airborne expeditions, Sever, which operated in late winter 1959-1986, in the Arctic and made snow measurements on the ice around plane landing sites. The snow measurements were made on the multiyear ice in the central Arctic and on the first-year ice in the Eurasian seas in the areas for which snow characteristics are poorly described in the literature. The main goal of this study is to produce an improved data set of snow depth on the sea ice. Read more
Brief communication: Unabated wastage of the Juneau and Stikine icefields (southeast Alaska) in the early 21st century The Cryosphere DOI 10.5194/tc-12-1523-2018 27 April 2018 Two recent studies suggested a slowdown in mass loss after 2000 of the Juneau and Stikine icefields, accounting for 10% of the total ice cover in Alaska. Here, the ASTER-based geodetic mass balances are revisited, carefully avoiding the use of the SRTM DEM, because of the unknown penetration depth of the SRTM C-band radar signal. We find strongly negative mass balances from 2000 to 2016 for both icefields, in agreement with airborne laser altimetry. Mass losses are thus continuing unabated. Read more
The influence of atmospheric grid resolution in a climate model-forced ice sheet simulation The Cryosphere DOI 10.5194/tc-12-1499-2018 23 April 2018 Coupled climate–ice sheet simulations have been growing in popularity in recent years. Experiments of this type are however challenging as ice sheets evolve over multi-millennial timescales, which is beyond the practical integration limit of most Earth system models. A common method to increase model throughput is to trade resolution for computational efficiency (compromise accuracy for speed). Here we analyze how the resolution of an atmospheric general circulation model (AGCM) influences the simulation quality in a stand-alone ice sheet model. Four identical AGCM simulations of the Last Glacial Maximum (LGM) were run at different horizontal resolutions: T85 (1.4∘), T42 (2.8∘), T31 (3.8∘), and T21 (5.6∘). These simulations were subsequently used as forcing of an ice sheet model. Read more
Climate change and the global pattern of moraine-dammed glacial lake outburst floods The Cryosphere DOI 10.5194/tc-12-1195-2018 9 April 2018 Most mountain glaciers have receded throughout the last century in response to global climate change. This recession produces a range of natural hazards including glacial lake outburst floods (GLOFs). We have produced the first global inventory of GLOFs associated with the failure of moraine dams and show, counterintuitively, that these have reduced in frequency over recent decades. In this paper we explore the reasons for this pattern. Read more
On the retrieval of sea ice thickness and snow depth using concurrent laser altimetry and L-band remote sensing data The Cryosphere DOI 10.5194/tc-12-993-2018 22 March 2018 This work proposes a new data synergy method for the retrieval of sea ice thickness and snow depth by using colocating L-band passive remote sensing and active laser altimetry. Physical models are adopted for the retrieval, including L-band radiation model and buoyancy relationship. Covariability of snow depth and total freeboard is further utilized to mitigate resolution differences and improve retrievability. The method can be applied to future campaigns including ICESat-2 and WCOM. Read more
The European mountain cryosphere: a review of its current state, trends, and future challenges The Cryosphere DOI 10.5194/tc-12-759-2018 1 March 2018 This paper makes a rather exhaustive overview of current knowledge of past, current, and future aspects of cryospheric issues in continental Europe and makes a number of reflections of areas of uncertainty requiring more attention in both scientific and policy terms. The review paper is completed by a bibliography containing 350 recent references that will certainly be of value to scholars engaged in the fields of glacier, snow, and permafrost research. Read more
On the similarity and apparent cycles of isotopic variations in East Antarctic snow pits The Cryosphere DOI 10.5194/tc-12-169-2018 17 January 2018 We explain why snow pits across different sites in East Antarctica show visually similar isotopic variations. We argue that the similarity and the apparent cycles of around 20 cm in the δD and δ18O variations are the result of a seasonal cycle in isotopes, noise, for example from precipitation intermittency, and diffusion. The near constancy of the diffusion length across many ice-coring sites explains why the structure and cycle length is largely independent of the accumulation conditions. Read more
In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems The Cryosphere DOI 10.5194/tc-11-2943-2017 14 December 2017 Geophysical methods have wide applications to permafrost studies. We show that borehole nuclear magnetic resonance is a valuable geophysical tool to rapidly characterize the liquid water content and unfrozen pore space in warm permafrost through simulation and field study. This technique is also sensitive to the ice nucleation process in situ. This method, which is applicable in a variety of soil types, can be used for single observations or for time-lapse monitoring of permafrost changes. Read more
A multilayer physically based snowpack model simulating direct and indirect radiative impacts of light-absorbing impurities in snow The Cryosphere DOI 10.5194/tc-11-2633-2017 20 November 2017 Light-absorbing impurities deposited on snow, such as soot or dust, strongly modify its evolution. We implemented impurity deposition and evolution in a detailed snowpack model, thereby expanding the reach of such models into addressing the subtle interplays between snow physics and impurities’ optical properties. Model results were evaluated based on innovative field observations at an Alpine site. This allows future investigations in the fields of climate, hydrology and avalanche prediction. Read more
