Refine my results

Language

Université de Fribourg

The firn meltwater retention model intercomparison project (retmip) : evaluation of nine firn models at four weather station sites on the greenland ice sheet

Vandecrux, Baptiste ; Mottram, Ruth ; Langen, Peter L. ; Fausto, Robert S. ; Olesen, Martin ; Stevens, C. Max ; Verjans, Vincent ; Leeson, Amber ; Ligtenberg, Stefan ; Munneke, Peter Kuipers ; Marchenko, Sergey ; Pelt, Ward van ; Meyer, Colin R. ; Simonsen, Sebastian B. ; Heilig, Achim ; Samimi, Samira ; Marshall, Shawn ; Machguth, Horst ; MacFerrin, Michael ; Niwano, Masashi ; Miller, Olivia ; Voss, Clifford I. ; Box, Jason E.

In: The Cryosphere, 2020, vol. 14, no. 11, p. 3785-3810

Perennial snow, or firn, covers 80 % of the Greenland ice sheet and has the capacity to retain surface meltwater, influencing the ice sheet mass balance and contribution to sea-level rise. Multilayer firn models are traditionally used to simulate firn processes and estimate meltwater retention. We present, intercompare and evaluate outputs from nine firn models at four sites that represent...

Université de Fribourg

A general theory of rock glacier creep based on in-situ and remote sensing observations

Cicoira, Alessandro ; Marcer, Marco ; Gärtner‐Roer, Isabelle ; Bodin, Xavier ; Arenson, Lukas U. ; Vieli, Andreas

In: Permafrost and Periglacial Processes, 2020, vol. 32, no. 1, p. 139-153

The ongoing acceleration in rock glacier velocities concurrent with increasing air temperatures, and the widespread onset of rock glacier destabilization have reinforced the interest in rock glacier dynamics and in its coupling to the climate system. Despite the increasing number of studies investigating this phenomenon, our knowledge of both the fundamental mechanisms controlling rock...

Université de Fribourg

The importance of input data quality and quantity in climate field reconstructions – results from the assimilation of various tree-ring collections

Franke, Jörg ; Valler, Veronika ; Brönnimann, Stefan ; Neukom, Raphael ; Jaume-Santero, Fernando

In: Climate of the Past, 2020, vol. 16, no. 3, p. 1061–1074

Differences between paleoclimatic reconstructions are caused by two factors: the method and the input data. While many studies compare methods, we will focus in this study on the consequences of the input data choice in a state-of-the-art Kalman- filter paleoclimate data assimilation approach. We evaluate reconstruction quality in the 20th century based on three collections of tree-ring...

Université de Fribourg

Reversed surface-mass-balance gradients on himalayan debris-covered glaciers inferred from remote sensing

Bisset, Rosie R. ; Dehecq, Amaury ; Goldberg, Daniel N. ; Huss, Matthias ; Bingham, Robert G. ; Gourmelen, Noel

In: Remote Sensing, 2020, vol. 12, no. 10, p. 1563

Meltwater from the glaciers in High Mountain Asia plays a critical role in water availability and food security in central and southern Asia. However, observations of glacier ablation and accumulation rates are limited in spatial and temporal scale due to the challenges that are associated with fieldwork at the remote, high-altitude settings of these glaciers. Here, using a...

Université de Fribourg

Estimating glacier-bed overdeepenings as possible sites of future lakes in the de-glaciating Mont Blanc massif (Western European Alps)

Magnin, F. ; Haeberli, W. ; Linsbauer, Andreas ; Deline, P. ; Ravanel, L.

In: Geomorphology, 2020, vol. 350, p. 106913

De-glaciating high mountain areas result in new landscapes of bedrock and debris where permafrost can degrade, persist or even newly form in cases, and of new lakes in glacier bed overdeepenings (GBOs) becoming ice-free. These landscapes with new lakes in close neighborhood to over-steepened and perennially frozen slopes are prone to chain reaction processes (e.g. rock-ice avalanches into...

Université de Fribourg

Algal growth and weathering crust state drive variability in western Greenland Ice Sheet ice albedo

Tedstone, Andrew J. ; Cook, Joseph M. ; Williamson, Christopher J. ; Hofer, Stefan ; McCutcheon, Jenine ; Irvine-Fynn, Tristram ; Gribbin, Thomas ; Tranter, Martyn

In: The Cryosphere, 2020, vol. 14, no. 2, p. 521–538

One of the primary controls upon the melting of the Greenland Ice Sheet (GrIS) is albedo, a measure of how much solar radiation that hits a surface is reflected without being absorbed. Lower-albedo snow and ice surfaces therefore warm more quickly. There is a major difference in the albedo of snow-covered versus bare-ice surfaces, but observations also show that there is substantial spatio-...

Université de Fribourg

Direct observations of a three million cubic meter rock-slope collapse with almost immediate initiation of ensuing debris flows

Walter, Fabian ; Amann, Florian ; Kos, Andrew ; Kenner, Robert ; Phillips, Marcia ; Preux, Antoine de ; Huss, Matthias ; Tognacca, Christian ; Clinton, John ; Diehl, Tobias ; Bonanomi, Yves

In: Geomorphology, 2020, vol. 351, p. 106933

Catastrophic collapse of large rock slopes ranks as one of the most hazardous natural phenomena in mountain landscapes. The cascade of events, from rock- slope failure, to rock avalanche and the near-immediate release of debris flows has not previously been described from direct observations. We report on the 2017, 3.0 × 106 m3 failure on Pizzo Cengalo in Switzerland, which led to human...

Université de Fribourg

Assessing the potential of soil moisture measurements for regional landslide early warning

Wicki, Adrian ; Lehmann, Peter ; Hauck, Christian ; Seneviratne, Sonia I. ; Waldner, Peter ; Stähli, Manfred

In: Landslides, 2020, p. -

In mountainous terrain, rainfall-induced landslides pose a serious risk to people and infrastructure. Regional landslide early warning systems (LEWS) have proven to be a cost-efficient tool to inform the public about the imminent landslide danger. While most operational LEWS are based on rainfall exceedance thresholds only, recent studies have demonstrated an improvement of the forecast...

Université de Fribourg

Future shifts in extreme flow regimes in Alpine regions

Brunner, Manuela I. ; Farinotti, Daniel ; Zekollari, Harry ; Huss, Matthias ; Zappa, Massimiliano

In: Hydrology and Earth System Sciences, 2019, vol. 23, no. 11, p. 4471–4489

Extreme low and high flows can have negative economic, social, and ecological effects and are expected to become more severe in many regions due to climate change. Besides low and high flows, the whole flow regime, i.e., annual hydrograph comprised of monthly mean flows, is subject to changes. Knowledge on future changes in flow regimes is important since regimes contain information on both ...