Glacier dynamics & climate change

Glaciers are excellent indicators of climate change and quickly respond to already small changes in atmospheric forcing. In order to understand the processes driving glacier retreat in the Alps and worldwide we monitor glacier change (link to cluster 1), develop new measurement approaches and methodologies to analyze in-situ and remotely-sensed data, and use a variety of model approaches for simulating the past and future response of glaciers to changing climate conditions.

We presently focus on feedback mechanisms affecting glacier melt, methods for measuring glacier mass change at local to regional scales and a better representation of snow precipitation in high mountain areas.

 

SEON (Swiss Earth Observatory Network)

The Swiss Earth Observatory Network (SEON) is a competence centre to monitor status and functioning of Swiss ecosystems in a changing environment. An increasing demand for natural resources impacts important biotic and physical processes within the Earth system and causes complex interactions within terrestrial ecosystems. SEON pursues a holistic Earth system science approach to assess environmental change impacts on ecosystem functioning and considers complex feedback mechanisms between the Earth spheres, including the human impact.

The contribution of the University of Fribourg focuses on the use of albedo products from the air-borne multispectral imagery for glacier melt modelling and process understanding. In particular, the reasons for the presently observed darkening of alpine glacier surfaces, i.e. its components and drivers, will be investigated on several Swiss glaciers.

Webpage: www.seon.uzh.ch 

Duration: 2013-2016

Funded by: State Secretariat for Education, Research and Innovation (SBF) and ETH-Board as a Cooperation and Innovation Project (KIP) initiated by the Swiss University Conference (SUK).
Project lead/principal investigator (PI): M. Schaepmann, Remote Sensing Laboratories, University of Zurich 

Partner(s): University of Zurich, ETH Zurich, EAWAG, EMPA, Agroscope

Collaborators: Kathrin Naegeli (PhD student), Matthias Huss (PostDoc), Martin Hoelzle (Prof.)

External collaboration with:


Publications:

Naegeli, K., Damm, A., Huss, M., Schaepman, M. and Hoelzle, M. (2015). Imaging spectroscopy to assess the composition of ice surface materials and their impact on glacier mass balance. Remote Sensing of Environment, 168, 388-402. doi:10.1016/j.rse.2015.07.006

 

Research aims/sciences questions:
(1) What is the surface albedo of a glacier and how is its distribution?
(2) What kind of components (mineral, organic) are present on a glacier surface and how are they altering the glacier surface albedo?
(3) How does the surface albedo of glaciers change over different time-scales?
(4) How is the glacier surface albedo altering glacier melt processes?

Methods/methodology of the project: airborne imaging spectroscopy (Airborne Prism EXperiment – APEX), satellite remote sensing, field spectroscopy, portable, in-situ albedo measurements, automatic weather station, direct glaciological mass balance measurements

Study area: Glacier de la Plaine Morte (Valais), Findelengletscher (Valais)

 

Exemplary results:

Figure 1 Surface classification of Glacier de la Plaine Morte based on the APEX scene taken on the 31th of August 2013.

Snowline observations to remotely derive seasonal to sub-seasonal glacier mass balance in the Tien Shan and Pamir Mountains

Glacier mass balance is a valuable indicator of climate change. However, in remote areas as Central Asia novel approaches are required to infer mass balance at high temporal and spatial resolution without direct field-site access. We apply and refine a new approach to four Kyrgyz glaciers in the framework of this project. This methodology should enable an efficient remote determination of the glacier mass balance based on repeated snowline observations throughout the ablation season.

In a second step, the methodology is applied to a large number of glaciers in remote and inaccessible regions of the Tien Shan and Pamir Mountains in Central Asia, where in-situ measurements are not feasible. An automatic routine to detect the snowline position over the glacier area based on satellite imagery will allow a fast and inexpensive way to monitor glacier mass balance without the need of direct measurements.

 

Webpage: http://p3.snf.ch/project-155903#

 

Duration: 01.01.2015 - 31.12.2017

 

Funded by: Swiss National Science Foundation (SNSF), grant 200021 155903

 

Project lead/principal investigators (PIs): Prof. M. Hoelzle, Département des Géosciences Université de Fribourg; Matthias Huss, Département des Géosciences Université de Fribourg and VAW, ETH Zürich; Frank Paul, Geographisches Institut Universität Zürich; Tobias Bolch, Geographisches Institut Universität Zürich.

 

 

Partner(s): University of Zurich, CAIAG Kyrgyzstan, GFZ Potsdam

 

Collaborators: Martina Barandun (PhD student)

 

Contact at University of Fribourg: martina.barandun@unifr.ch, matthias.huss@unifr.ch, martin.hoelzle@unifr.ch

 

Publications:

Barandun, M., Huss, M., Sold, L., Farinotti, D., Azisov, E., Salzmann, N., Usubaliev, R., Merkushkin, A., & Hoelzle, M. (2015). Re-analysis of seasonal mass balance at Abramov glacier 1968–2014. Journal of Glaciology, 61(230), 1103-1117.

Kronenberg, M., Barandun, M., Hoelzle, M., Huss, M., Farinotti, D., Azisov, E., ... & Kääb, A. (2016). Mass-balance econstruction for Glacier No. 354, Tien Shan, from 2003 to 2014. Annals of Glaciology, 57, 71.

Kenzhebaev, R., Barandun, M., Kronenberg, M., Yaning, C., Usubaliev, R., Hoelzle, M., (in review). Mass balance observation and reconstruction for Batysh Sook Glacier, Tian Shan, from 2004 to 2015. Cold Region Science and Technology.

 

Research aims/sciences questions:
(1) Can glacier-wide mass balance be derived from transient snowline observations?
(2) Does the proposed methodology allow the calculation of the mass balance for individual glaciers without in-situ measurements?
(3) Can mass balance be estimated region wide, purely based on transient snowline observations?

Methods/methodology of the project: snowline and mass balance modelling, remote sensing (ground based camera and satellite), direct glaciological mass balance measurements, geodetic mass balance

Study area: Kyrgyz Tien Shan and Pamir mountains (Kyrgyzstan). Selected glaciers: Abramov Glacier (Pamir-Alay), Golubin Glacier, Batysh Sook and Glacier No.354 (Tien Shan)

Exemplary results:

Figure 1a: Ground based Mobotix camera image of Abramov Glacier from early June 2015. 

Figure 2: Ablation measurement at Golubin Glacier.

Figure 3: Image of Glacier No. 354 taken by the terrestrial camera eight times per day. 

 

References:

Huss, M., Sold, L., Hoelzle, M., Stokvis, M., Salzmann, N., Farinotti, D., Zemp, M. (2013) Toward remote monitoring of sub-seasonal glacier mas balance. Annals of Glaciology 63, 85-93


Changing glacier firn in Central Asia and its impact on Glacier mass balance

The glaciated regions of Central Asia serve as water towers on a regional scale. For this dry region, the monitoring of glacier mass balance therefore provides valuable information for the estimation of water availability. In the 1990s, related to the end of the Soviet period, monitoring programmes were interrupted. On selected glaciers, the University of Fribourg and partner institutes could successfully reinitiate a mass balance monitoring. However, comparisons between in-situ measured mass balances and mass balance estimations based on remote sensing data reveal differences between the results both methods.

Major uncertainties in both approaches relate to the little explored changes in the firn cover, i.e. the porous and up to a few dozen meter thick near-surface layer of a glacier where snow densifies into glacier ice. Therefore, changes of meltwater percolation and retention in firn, and associated changes in firn density and/or temperature could possibly explain the differences between both methods.


Webpage: http://p3.snf.ch/project-169453

 

Duration: 01.04.2017 - 31.03.2020

 

Funded by: Swiss National Science Foundation (SNSF), grant 200021_169453

 

Project lead/principal investigators (PIs): Dr. Horst Machguth Département des Géosciences Université de Fribourg; Prof. Dr. Martin Hoelzle, Département des Géosciences Université de Fribourg

 

Partner(s): PSI, University of Zurich, LEGOS Toulouse, University of Uppsala, CAIAG Kyrgyzstan, AWI Bremerhaven

 

Collaborators: Marlene Kronenberg (PhD student)

 

Contact at University of Fribourg: marlene.kronenberg@unifr.ch, horst.machguth@unifr.ch, martin.hoelzle@unifr.ch

 

Research aims/sciences questions:
(1) Establishing a century long accumulation time series of Abramov Glacier.
(2) Design a firn model, calibrated with the measurements and applied to simulate and understand the processes in firn evolution.
(3) Apply the measurements and model to reconcile geodetic and in-situ glacier mass balances.

Methods/methodology of the project: Firn core drilling and analysis, legacy data, firn and glacier mass balance model, remote sensing

 

Study area: Glaciers in the Central Asian Tien Shan and Pamir mountains. Main focus on Abramov Glacier (Pamir-Alay).

 

Exemplary results:

Figure 1: Two examples of firn stratigraphy and density measured in 1974/75 deep snow pits on Abramov glacier (source: Suslov and Krenke, 1980, stratigraphy is simplified compared to original source).

 

Figure 2: Abramov glacier (Picture taken by Horst Machguth).

References:

Suslov, V F and Krenke, A V (1980). Lednik Abramova (Alajskij chrebet). Girdometeoizdat.

 

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Unit of Geography - Chemin du Musée 4 - 1700 Fribourg - Tel +41 26 / 300 90 10 - Fax +41 26 / 300 9746
nicole.equey [at] unifr.ch - Swiss University