Zürich, Switzerland
Zürich, Switzerland

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Bader K.,SBB AG Fahrstrom | Golle I.,SBB AG | Holderegger M.,SBB AG | Zesiger R.,SBB AG | And 2 more authors.
eb - Elektrische Bahnen | Year: 2015

The Swiss Railway Company investigated the heating of their overhead contact lines. The developed physical models were verified by measurements on contact lines in operation by a newly developed measuring device [1]. This device measures the temperatures at the live contact line. The device has been in operation since 2014. It provides reliably the wanted data. The device can be operated with or without devices to monitor the meteorological conditions.


Golle I.,SBB AG | Holderegger M.,SBB AG | Steinegger U.,Meteodat GmbH
eb - Elektrische Bahnen | Year: 2015

The heating of the components of overhead contact lines depends not only on the flowing currents but also on the ambient meteorological conditions. Solar heating, velocity and direction of the wind and air temperature form essential effects. Swiss Railways SBB developed models for calculating the thermal behavior of contact lines which adequately consider these factors. The models were validated by measurements at overhead contact lines in operation. It is planned to utilize the results for parameterizing the thermal contact line protection equipment.


Grant
Agency: European Commission | Branch: H2020 | Program: IA | Phase: DRS-01-2015 | Award Amount: 14.54M | Year: 2016

The ultimate purpose of ANYWHERE is to empower exposed responder institutions and citizens to enhance their anticipation and pro-active capacity of response to face extreme and high-impact weather and climate events. This will be achieved through the operational implementation of cutting-edge innovative technology as the best way to enhance citizens protection and saving lives. ANYWHERE proposes to implement a Pan-European multi-hazard platform providing a better identification of the expected weather-induced impacts and their location in time and space before they occur. This platform will support a faster analysis and anticipation of risks prior the event occurrence, an improved coordination of emergency reactions in the field and help to raise the self-preparedness of the population at risk. This significant step-ahead in the improvement of the pro-active capacity to provide adequate emergency responses is achievable capitalizing on the advanced forecasting methodologies and impact models made available by previous RTD projects, maximizing the uptake of their innovative potential not fully exploited up to now. The consortium is build upon a strong group of Coordinators of previous key EC projects in the related fields, together with 12 operational authorities and first responders institutions and 6 leading enterprises of the sector. The platform will be adapted to provide early warning products and locally customizable decision support services proactively targeted to the needs and requirements of the regional and local authorities, as well as public and private operators of critical infrastructures and networks. It will be implemented and demonstrated in 4 selected pilot sites to validate the prototype that will be transferred to the real operation. The market uptake will be ensured by the cooperation with a SME and Industry Collaborative Network, covering a wide range of sectors and stakeholders in Europe, and ultimately worldwide.


Rohrer M.,Meteodat GmbH | Salzmann N.,University of Fribourg | Stoffel M.,University of Geneva | Stoffel M.,University of Bern | Kulkarni A.V.,Indian Institute of Science
Science of the Total Environment | Year: 2014

The Himalayas are presently holding the largest ice masses outside the polar regions and thus (temporarily) store important freshwater resources. In contrast to the contemplation of glaciers, the role of runoff from snow cover has received comparably little attention in the past, although (i) its contribution is thought to be at least equally or even more important than that of ice melt in many Himalayan catchments and (ii) climate change is expected to have widespread and significant consequences on snowmelt runoff. Here, we show that change assessment of snowmelt runoff and its timing is not as straightforward as often postulated, mainly as larger partial pressure of H2O, CO2, CH4, and other greenhouse gases might increase net long-wave input for snowmelt quite significantly in a future atmosphere. In addition, changes in the short-wave energy balance - such as the pollution of the snow cover through black carbon - or the sensible or latent heat contribution to snowmelt are likely to alter future snowmelt and runoff characteristics as well. For the assessment of snow cover extent and depletion, but also for its monitoring over the extremely large areas of the Himalayas, remote sensing has been used in the past and is likely to become even more important in the future. However, for the calibration and validation of remotely-sensed data, and even more so in light of possible changes in snow-cover energy balance, we strongly call for more in-situ measurements across the Himalayas, in particular for daily data on new snow and snow cover water equivalent, or the respective energy balance components. Moreover, data should be made accessible to the scientific community, so that the latter can more accurately estimate climate change impacts on Himalayan snow cover and possible consequences thereof on runoff. © 2013 Elsevier B.V.


Salzmann N.,University of Zürich | Salzmann N.,University of Fribourg | Huggel C.,University of Zürich | Rohrer M.,Meteodat GmbH | And 4 more authors.
Cryosphere | Year: 2013

The role of glaciers as temporal water reservoirs is particularly pronounced in the (outer) tropics because of the very distinct wet/dry seasons. Rapid glacier retreat caused by climatic changes is thus a major concern, and decision makers demand urgently for regional/local glacier evolution trends, ice mass estimates and runoff assessments. However, in remote mountain areas, spatial and temporal data coverage is typically very scarce and this is further complicated by a high spatial and temporal variability in regions with complex topography. Here, we present an approach on how to deal with these constraints. For the Cordillera Vilcanota (southern Peruvian Andes), which is the second largest glacierized cordillera in Peru (after the Cordillera Blanca) and also comprises the Quelccaya Ice Cap, we assimilate a comprehensive multi-decadal collection of available glacier and climate data from multiple sources (satellite images, meteorological station data and climate reanalysis), and analyze them for respective changes in glacier area and volume and related trends in air temperature, precipitation and in a more general manner for specific humidity. While we found only marginal glacier changes between 1962 and 1985, there has been a massive ice loss since 1985 (about 30% of area and about 45% of volume). These high numbers corroborate studies from other glacierized cordilleras in Peru. The climate data show overall a moderate increase in air temperature, mostly weak and not significant trends for precipitation sums and probably cannot in full explain the observed substantial ice loss. Therefore, the likely increase of specific humidity in the upper troposphere, where the glaciers are located, is further discussed and we conclude that it played a major role in the observed massive ice loss of the Cordillera Vilcanota over the past decades. © Author(s) 2013.


Sorg A.,University of Geneva | Sorg A.,University of Bern | Huss M.,University of Fribourg | Rohrer M.,Meteodat GmbH | And 2 more authors.
Environmental Research Letters | Year: 2014

Despite the fact that the fast-growing population of Central Asia strongly depends on glacial melt water for fresh water supply, irrigation and hydropower production, the impact of glacier shrinkage on water availability remains poorly understood. With an annual area loss of 0.36 to 0.76%, glaciers are retreating particularly fast in the northern Tien Shan, thus causing concern about future water security in the densely populated regions of Bishkek and Almaty. Here, we use exceptionally long in-situ data series to run and calibrate a distributed glacio-hydrological model, which we then force with downscaled data from phase five of the Climate Model Intercomparison Project CMIP5. We observe that even in the most glacier-friendly scenario, glaciers will lose up to two thirds (-60%) of their 1955 extent by the end of the 21st century. The range of climate scenarios translates into different changes in overall water availability, from peak water being reached in the 2020s over a gradual decrease to status quo until the end of the 21st century. The days of plenty, however, will not last much longer, as summer runoff is projected to decrease, independent of scenario uncertainty. These results highlight the need for immediate planning of mitigation measures in the agricultural and energy sectors to assure long-term water security in the densely populated forelands of the Tien Shan. © 2014 IOP Publishing Ltd.


Salzmann N.,University of Fribourg | Salzmann N.,University of Zürich | Huggel C.,University of Zürich | Rohrer M.,Meteodat GmbH | And 2 more authors.
Journal of Hydrology | Year: 2014

Glacier and snow cover changes with related impacts on melt runoff can seriously affect human societies which are depending on fresh water from cryospheric sources. Observed trends and projected future evolutions of climatic and cryospheric variables clearly show the need to adapt to these changes. Accordingly, the topics addressed herein have been put on the agendas of many larger funding agencies. This article provides a brief overview on major ongoing activities on glacier, snow and related runoff research in order to then analyze data gaps and research needs from a climate change adaptation perspective. Major data needs are identified with respect to the spatial and temporal coverage of local-scale data and related needs for (data) services that distribute and maintain these data sets. Moreover, clear research needs are also recognized at the local scale where process knowledge needs to be improved (e.g., the influence of albedo on snow and ice or debris cover on glaciers) in order to derive plausible climate change impacts assessments. The paper then discusses directions on how to move forward to better serve the practical needs for climate change adaptation planning. In the future, substantial support by large funding agencies might be key for capacity building in target regions of climate change adaptation programs, for longer-term and more sustainable commitments, and for the development of approaches, which aim at assessing the transferability of data, techniques, and tools. © 2014 Elsevier B.V.


Huggel C.,University of Zürich | Rohrer M.,Meteodat GmbH | Calanca P.,ART Agroscope Reckenholz Tänikon | Salzmann N.,University of Zürich | And 3 more authors.
Eos | Year: 2012

Recent scientific assessment studies of climate change impacts, including those from the Intergovernmental Panel on Climate Change, provide evidence of the negative effects of climate variability and change on natural and human systems. For instance, recent climate trends have caused loss in wheat and maize production, negatively affected coral reefs, and changed characteristics of some hazards in high-mountain regions. Assessment studies furthermore suggest that related risks to ecosystems, commerce, and daily life may increase over the coming decades as temperatures warm. Adaptation to climate change is required to reduce the effects of unavoidable changes, especially for the most vulnerable regions and populations. © 2012. American Geophysical Union. All Rights Reserved.


Schauwecker S.,Meteodat GmbH | Schauwecker S.,University of Zürich | Rohrer M.,Meteodat GmbH | Acuna D.,SENAMHI | And 11 more authors.
Global and Planetary Change | Year: 2014

The total glacial area of the Cordillera Blanca, Peru, has shrunk by more than 30% in the period of 1930 to the present with a marked glacier retreat also in the recent decades. The aim of this paper is to assess local air temperature and precipitation changes in the Cordillera Blanca and to discuss how these variables could have affected the observed glacier retreat between the 1980s and present. A unique data set from a large number of stations in the region of the Cordillera Blanca shows that after a strong air temperature rise of about 0.31. °C per decade between 1969 and 1998, a slowdown in the warming to about 0.13. °C per decade occurred for the 30. years from 1983 to 2012. Additionally, based on data from a long-term meteorological station, it was found that the freezing line altitude during precipitation days has probably not increased significantly in the last 30. years. We documented a cooling trend for maximum daily air temperatures and an increase in precipitation of about 60. mm/decade since the early 1980s. The strong increase in precipitation in the last 30. years probably did not balance the increase of temperature before the 1980s. It is suggested that recent changes in temperature and precipitation alone may not explain the glacial recession within the thirty years from the early 1980s to 2012. Glaciers in the Cordillera Blanca may be still reacting to the positive air temperature rise before 1980. Especially small and low-lying glaciers are characterised by a serious imbalance and may disappear in the near future. © 2014 Elsevier B.V.


PubMed | University of Bern, Meteodat GmbH, Indian Institute of Science and University of Fribourg
Type: | Journal: The Science of the total environment | Year: 2014

The Himalayas are presently holding the largest ice masses outside the polar regions and thus (temporarily) store important freshwater resources. In contrast to the contemplation of glaciers, the role of runoff from snow cover has received comparably little attention in the past, although (i) its contribution is thought to be at least equally or even more important than that of ice melt in many Himalayan catchments and (ii) climate change is expected to have widespread and significant consequences on snowmelt runoff. Here, we show that change assessment of snowmelt runoff and its timing is not as straightforward as often postulated, mainly as larger partial pressure of H2O, CO2, CH4, and other greenhouse gases might increase net long-wave input for snowmelt quite significantly in a future atmosphere. In addition, changes in the short-wave energy balance - such as the pollution of the snow cover through black carbon - or the sensible or latent heat contribution to snowmelt are likely to alter future snowmelt and runoff characteristics as well. For the assessment of snow cover extent and depletion, but also for its monitoring over the extremely large areas of the Himalayas, remote sensing has been used in the past and is likely to become even more important in the future. However, for the calibration and validation of remotely-sensed data, and even more so in light of possible changes in snow-cover energy balance, we strongly call for more in-situ measurements across the Himalayas, in particular for daily data on new snow and snow cover water equivalent, or the respective energy balance components. Moreover, data should be made accessible to the scientific community, so that the latter can more accurately estimate climate change impacts on Himalayan snow cover and possible consequences thereof on runoff.

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