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Université de Fribourg

Re-establishing glacier monitoring in Kyrgyzstan and Uzbekistan, Central Asia

Hoelzle, Martin ; Azisov, Erlan ; Barandun, Martina ; Huss, Matthias ; Farinotti, Daniel ; Gafurov, Abror ; Hagg, Wilfried ; Kenzhebaev, Ruslan ; Kronenberg, Marlene ; Machguth, Horst ; Merkushkin, Alexandr ; Moldobekov, Bolot ; Petrov, Maxim ; Saks, Tomas ; Salzmann, Nadine ; Schöne, Tilo ; Tarasov, Yuri ; Usubaliev, Ryskul ; Vorogushyn, Sergiy ; Yakovlev, Andrey ; Zemp, Michael

In: Geoscientific Instrumentation, Methods and Data Systems, 2017, vol. 6, no. 2, p. 397–418

Glacier mass loss is among the clearest indicators of atmospheric warming. The observation of these changes is one of the major objectives of the international climate monitoring strategy developed by the Global Climate Observing System (GCOS). Long-term glacier mass balance measurements are furthermore the basis for calibrating and validating models simulating future runoff of glacierised...

Université de Fribourg

Mass balance observations and reconstruction for Batysh Sook Glacier, Tien Shan, from 2004 to 2016

Kenzhebaev, Ruslan ; Barandun, , Martina ; Kronenberg, Marlene ; Chen, Yaning ; Usubaliev, , Ryskul ; Hoelzle, Martin

In: Cold Regions Science and Technology, 2017, vol. 135, p. 76–89

In this study we present an analysis of measured annual mass balances for the period 2011 to 2016 and a reconstruction of seasonal mass balances from 2004 to 2010 for Batysh Sook Glacier located in the Kyrgyz Tien Shan. Conventional methods and a model-based extrapolation of the point measurements were used to obtain glacier-wide mass balances and to analyze glaciological measurements....

Université de Fribourg

Glacier monitoring and capacity building: important ingredients for sustainable mountain development

Nussbaumer, Samuel U. ; Hoelzle, Martin ; Hüsler, Fabia ; Huggel, Christian ; Salzmann, Nadine ; Zemp, Michael

In: Mountain Research and Development, 2017, vol. 37, no. 1, p. 141–152

Glacier observation data from major mountain regions of the world are key to improving our understanding of glacier changes: they deliver fundamental baseline information for climatological, hydrological, and hazard assessments. In many mountain ecosystems, as well as in the adjacent lowlands, glaciers play a crucial role in freshwater provision and regulation. This article first presents the...

Université de Fribourg

Distributed snow and rock temperature modelling in steep rock walls using Alpine3D

Haberkorn, Anna ; Wever, Nander ; Hoelzle, Martin ; Phillips, Marcia ; Kenner, Robert ; Bavay, Mathias ; Lehning, and Michael

In: The Cryosphere, 2017, vol. 11, no. 1, p. 585–607

In this study we modelled the influence of the spatially and temporally heterogeneous snow cover on the surface energy balance and thus on rock temperatures in two rugged, steep rock walls on the Gemsstock ridge in the central Swiss Alps. The heterogeneous snow depth distribution in the rock walls was introduced to the distributed, process-based energy balance model Alpine3D with a...

Université de Fribourg

Cross-comparison of albedo products for glacier surfaces derived from airborne and satellite (sentinel-2 and landsat 8) optical data

Naegeli, Kathrin ; Damm, Alexander ; Huss, Matthias ; Wulf, Hendrik ; Schaepman, Michael ; Hoelzle, Martin

In: Remote Sensing, 2017, vol. 9, no. 2, p. 110

Surface albedo partitions the amount of energy received by glacier surfaces from shortwave fluxes and modulates the energy available for melt processes. The ice- albedo feedback, influenced by the contamination of bare-ice surfaces with light- absorbing impurities, plays a major role in the melting of mountain glaciers in a warming climate. However, little is known about the spatial and...

Université de Fribourg

Mass-balance reconstruction for Glacier No. 354, Tien Shan, from 2003 to 2014

Kronenberg, Marlene ; Barandun, Martina ; Hoelzle, Martin ; Huss, Matthias ; Farinotti, Daniel ; Azisov, Erlan ; Usubaliev, Ryskul ; Gafurov, Abror ; Petrakov, Dmitry ; Kääb, Andreas

In: Annals of Glaciology, 2016, vol. 57, no. 71, p. 92–102

This study presents a reconstruction of the seasonal mass balance of Glacier No. 354, located in the Akshiirak range, Kyrgyzstan, from 2003 to 2014. We use a distributed accumulation and temperature-index melt model driven by daily air temperature and precipitation from a nearby meteorological station. The model is calibrated with in situ measurements of the annual mass balance collected from...

Université de Fribourg

Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland

Marmy, Antoine ; Rajczak, Jan ; Delaloye, Reynald ; Hilbich, Christin ; Hoelzle, Martin ; Kotlarski, Sven ; Lambiel, Christophe ; Noetzli, Jeannette ; Phillips, Marcia ; Salzmann, Nadine ; Staub, Benno ; Hauck, Christian

In: The Cryosphere, 2016, vol. 10, no. 6, p. 2693–2719

Permafrost is a widespread phenomenon in mountainous regions of the world such as the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which allow for the projection of the future...

Université de Fribourg

Application and validation of long-range terrestrial laser scanning to monitor the mass balance of very small glaciers in the Swiss Alps

Fischer, Mauro ; Huss, Matthias ; Kummert, Mario ; Hoelzle, Martin

In: The Cryosphere, 2016, vol. 10, no. 3, p. 1279–1295

Due to the relative lack of empirical field data, the response of very small glaciers (here defined as being smaller than 0.5 km²) to current atmospheric warming is not fully understood yet. Investigating their mass balance, e.g. using the direct glaciological method, is a prerequisite to fill this knowledge gap. Terrestrial laser scanning (TLS) techniques operating in the near infrared...

Université de Fribourg

Mass balance re-analysis of Findelengletscher, Switzerland; benefits of extensive snow accumulation measurements

Sold, Leo ; Huss, Matthias ; Machguth, Horst ; Joerg, Philip C. ; Leysinger Vieli, Gwendolyn ; Linsbauer, Andreas ; Salzmann, Nadine ; Zemp, Michael ; Hoelzle, Martin

In: Front. Earth Sci. - Cryospheric Sciences, 2016, p. 18

A re-analysis is presented here of a 10 year mass balance series at Findelengletscher, a temperate mountain glacier in Switzerland. Calculating glacier-wide mass balance from the set of glaciological point balance observations using conventional approaches, such as the profile or contour method, resulted in significant deviations from the reference value given by the geodetic mass...

Université de Fribourg

Imaging spectroscopy to assess the composition of ice surface materials and their impact on glacier mass balance

Naegeli, Kathrin ; Damm, Alexander ; Huss, Matthias ; Schaepman, Michael ; Hoelzle, Martin

In: Remote Sensing of Environment, 2015, vol. 168, p. 388–402

Glacier surfaces are not only composed of ice or snow but are heterogeneous mixtures of different materials. The occurrence and dynamics of light-absorbing impurities affect ice surface characteristics and strongly influence glacier melt processes. However, our understanding of the spatial distribution of impurities and their impact on ice surface characteristics and the glacier's energy budget...