Ulrich Strasser

University of Innsbruck | UIBK

This study aims at estimating the dry snow water equivalent (SWE) by using X-band synthetic aperture radar (SAR) data from the COSMO-SkyMed (CSK) satellite constellation. The time series of CSK acquisitions have been collected during the dry snow period in the Alto Adige test site, in the Italian Alps, during the winter seasons from 2013 to 2015 an...

The evaluation of snowpack models capable of accounting for snow management in ski resorts is a major step towards acceptance of such models in supporting the daily decision-making process of snow production managers. In the framework of the EU Horizon 2020 (H2020) project PROSNOW, a service to enable real-time optimization of grooming and snow-mak...

For a given research question, there are usually a large variety of possible analysis strategies acceptable according to the scientific standards of the field, and there are concerns that this multiplicity of analysis strategies plays an important role in the non-replicability of research findings. Here, we define a general framework on common sour...

According to the living data process in ESSD, this publication presents extensions of a comprehensive hydrometeorological and glaciological data set for several research sites in the Rofental (1891–3772 m a.s.l., Ötztal Alps, Austria). Whereas the original dataset has been published in a first original version in 2018 (https://doi.org/10.5194/essd-...

Spatio‐temporal variations of precipitation are presumed to influence the displacement rate of slow moving deep‐seated landslides by controlling groundwater recharge, pore‐water pressure and shear strength. Phases of landslide acceleration responding to long lasting rainfall and snowmelt events occur under site‐ and event‐specific time delays. Asse...

The European Alps stretch over a range of climate zones which affect the spatial distribution of snow. Previous analyses of station observations of snow were confined to regional analyses. Here, we present an Alpine-wide analysis of snow depth from six Alpine countries – Austria, France, Germany, Italy, Slovenia, and Switzerland – including altoget...

The evaluation of snowpack models capable of accounting for snow management in ski resorts is a major step towards acceptance of such models in supporting the daily decision-making process of snow production managers. In the frame of the EU H2020 project PROSNOW, a service to enable real-time optimisation of grooming and snow-making in ski resorts...

In snow-dominated river basins, floods often occur during early summer, when snowmelt-induced runoff superimposes with rainfall-induced runoff. An earlier onset of seasonal snowmelt as a consequence of a warming climate is often expected to shift snowmelt contribution to river runoff and potential flooding to an earlier date. Against this backgroun...

Snow models that solve coupled energy and mass balances require model parameters to be set, just like their conceptual counterparts. Despite the physical basis of these models, appropriate choices of the parameter values entail a rather high degree of uncertainty as some of them are not directly measurable, observations are lacking, or values are n...

The European Alps stretch over a range of climate zones, which affect the spatial distribution of snow. Previous analyses of station observations of snow were confined to regional analyses. Here, we present an Alpine wide analysis of snow depth from six Alpine countries: Austria, France, Germany, Italy, Slovenia, and Switzerland; including altogeth...

Twenty-seven models participated in the Earth System Model - Snow Model Intercomparison Project (ESM-SnowMIP), the most data-rich MIP dedicated to snow modelling. Our findings do not support the hypothesis advanced by previous snow MIPs: evaluating models against more variables, and providing evaluation datasets extended temporally and spatially do...

In dieser Studie konnte der Mehrwert zweier Tracer mit unterschiedlichem Informationsgehalt in synoptischer Analyse mit meteorologischen und hydrometrischen Daten (Lufttemperatur, Niederschlag, Durchfluss) für die Hydrologie vergletscherter Einzugsgebiete skizziert werden. Innerhalb dieser Studie wurde die zentrale Bedeutung der Schnee- und Gletsch...

Snow management, i. e., snowmaking and grooming, is an integral part of modern ski resort management. While the current snow cover distribution on the slopes is often well known thanks to the usage of advanced monitoring techniques, information about its future evolution is usually lacking. Management-enabled numerical snowpack models driven by met...

For a given research question, there are usually a large variety of possible analysis strategies acceptable according to the scientific standards of the field, and there are concerns that this multiplicity of analysis strategies plays an important role in the non-replicability of research findings. Here, we define a general framework on common sour...

Indicators are widely used in climate variability and climate change assessments to simplify the tracking of complex processes and phenomena in the state of the environment. Apart from the climatic criteria, the snow indicators in ski tourism have been increasingly extended with elements that relate to the technical, operational, and commercial asp...

This article presents an approach to improve the estimation of the glacier mass balance (GMB) of six selected alpine glaciers in the European Alps. This is achieved by combining three complementary data sources: hydroclimatological model, remote sensing (RS) data, and ground measurements. The hydroclimatological model provides spatially distributed...

Mountain regions with complex orography are a particular challenge for regional climate simulations. High spatial resolution is required to account for the high spatial variability in meteorological conditions. This study presents a very high-resolution regional climate simulation (5 km) using the Weather Research and Forecasting Model (WRF) for th...

Water is of uttermost importance for human well-being and a central resource in sustainable development. Many simulation models for sustainable water management, however, lack explanatory and predictive power because the two-way dynamic feedbacks between human and water systems are neglected. With Agent-based Modelling of Resources (Aqua.MORE; here...

We determined the streamflow transit time and the subsurface water storage volume in the glacierized high-elevation catchment of the Rofenache (Oetztal Alps, Austria) with the lumped parameter transit time model TRANSEP. Therefore we enhanced the surface energy-balance model ESCIMO to simulate the ice melt, snowmelt and rain input to the catchment...

The accurate monitoring and understanding of glacier dynamics are of high relevance for climate science and water-resources management. The glacier parameters are typically estimated by data assimilation methods which inject field measurements into the numerical simulations with the aim of improving the physical model estimates. However, these meth...

This paper presents a new concept to derive the snow water equivalent (SWE) based on the joint use of snow model (AMUNDSEN) simulation, ground data, and auxiliary products derived from remote sensing. The main objective is to characterize the spatial-temporal distribution of the model-derived SWE deviation with respect to the real SWE values derive...

This paper presents a novel data fusion technique for improving the snow cover monitoring for a mesoscale Alpine region, in particular in those areas where two information sources disagree. The presented methodological innovation consists in the integration of remote-sensing data products and the numerical simulation results by means of a machine l...

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, p...

In this study, we assess the impact of forcing data errors, model structure, and parameter choices on 1-D snow simulations simultaneously within a global variance-based sensitivity analysis framework. This approach allows inclusion of interaction effects, drawing a more representative picture of the resulting sensitivities. We utilize all combinati...

Mountain regions are climate sensitive zones and a particular challenge for regional climate and hydrology simulations. The complex orography with extreme elevation gradients, as well as varied land cover and ecosystems at small spatial scales lead to a high variability of climatic conditions and hydrological processes. We present a case study for...

This paper describes ESM-SnowMIP, an international coordinated modelling effort to evaluate current snow schemes, including snow schemes that are included in Earth system models, in a wide variety of settings against local and global observations. The project aims to identify crucial processes and characteristics that need to be improved in snow mo...

In this paper, the hydrological impacts of future socio-economic and climatic development are assessed for a regional-scale Alpine catchment (Brixental, Tyrol, Austria). Therefore, coupled storylines of future land use and climate scenarios were developed in a transdisciplinary stakeholder process by means of questionnaire analyses and interviews w...

While science widely acknowledges the necessity of climate change adaptation (CCA), concrete strategies for CCA by major land-use actor groups at a local level are largely missing. Immediate economic challenges often prevent the establishment of long-term collective strategies. However, collective decisions on a communal level regarding land use ar...

A distributed snow model is applied to simulate the spatiotemporal evolution of the Austrian snow cover at 1 km × 1 km spatial and daily temporal resolution for the period 1948-2009. After a comprehensive model validation, changes in snow cover conditions are analyzed for all of Austria as well as for different Austrian subregions and elevation bel...

We present a new model extension for the Water balance Simulation model, WaSiM, which features (i) snow interception and (ii) modified meteorological conditions under coniferous forest canopies, complementing recently developed model extensions for particular mountain hydrological processes. Two study areas in Austria and Germany are considered in...

This paper describes ESM-SnowMIP, an international coordinated modelling effort to evaluate current snow schemes against local and global observations in a wide variety of settings, including snow schemes that are included in Earth System Models. The project aims at identifying crucial processes and snow characteristics that need to be improved in...

For the elaboration of adaption strategies to long-term developments, socio-economic changes need to be included. Participatory scenario methods are a creative and flexible approach to consider uncertainties and serve as a transdisciplinary tool for mutual learning. Therefore, socio-economic scenarios provide comprehensive descriptions of future tr...

In diesem Beitrag werden aktuelle tracerhydrologische Forschungsarbeiten an der Rofenache dargelegt, deren hochalpines Einzugsgebiet in den hinteren Ötztaler Alpen liegt. Es wurden Wasserproben von Abfluss, flachgründigen Quellen, Regen, Schnee und Gletscher genommen und auf ihre Sauerstoff-18-Signatur und elektrische Leitfähigkeit analysiert. Die...

Alpine ecosystems provide a wide range of ecosystem services, with the provisioning service 'freshwater' being one of them. The Alps are 'water towers', contributing disproportionate amounts of runoff in comparison to lowland areas, hence being crucial for water accumulation and water supply not only for the headwater regions, but for large parts o...

Many energy-balance snow models have been developed over the last three decades with varying degrees of complexity. Typically, process-based models are not calibrated, relying on their parameters being physically meaningful and determinable in the field. In reality, however, many parameters of snow models are abstract, not easy to measure, or the r...

The new agent-based model Aqua.MORE is designed to simulate water fluxes at the human-environment interface in a coupled water supply/demand system at the catchment scale. It was developed in a joint cooperation of hydro-climatologists and ecologists. The agent based modelling (ABM) approach represents the relevant real-world entities as individual...

Der vorliegende Beitrag fasst die Ergebnisse eines transdisziplinären Forschungsprojekts zusammen, welches die komplexen Wechselwirkungen von Klima, Gesellschaft und Landnutzung integrativ unter-sucht und quantifiziert. Das Untersuchungsgebiet ist das 322 km² große Brixental in Tirol (Österreich). Im Rahmen des Projekts wurden hydrologische Simulat...

A physically based hydroclimatological model (AMUNDSEN) is used to assess future climate change impacts on the cryosphere and hydrology of the Ötztal Alps (Austria) until 2100. The model is run in 100 m spatial and 3 h temporal resolution using in total 31 downscaled, bias-corrected, and temporally disaggregated EURO-CORDEX climate projections for...

The mountain cryosphere of mainland Europe is recognized to have important impacts on a range of environmental processes. In this paper, we provide an overview on the current knowledge on snow, glacier, and permafrost processes, as well as their past, current, and future evolution. We additionally provide an assessment of current cryosphere researc...

This article presents analyses of retrospective seasonal forecasts of snow accumulation. Re-forecasts with 4 months' lead time from two coupled atmosphere–ocean general circulation models (NCEP CFSv2 and MetOffice GloSea5) drive the Alpine Water balance and Runoff Estimation model (AWARE) in order to predict mid-winter snow accumulation in the Inn...

A comprehensive hydrometeorological and glaciological data set is presented, originating from a multitude of glaciological, meteorological, hydrological and laser scanning recordings at research sites in the Rofental (1891–3772 m a.s.l., Ötztal Alps, Austria). The data sets span a period of 150 years and hence represent a unique time series of rich...

Geochemical and isotopic tracers were often used in mixing models to estimate glacier melt contributions to streamflow, whereas the spatio‐temporal variability in the glacier melt tracer signature and its influence on tracer‐based hydrograph separation results received less attention. We present novel tracer data from a high‐elevation catchment (17...

A comprehensive hydrometeorological and glaciological data set is presented, originating from a multitude of recordings at several intensively operated research sites in the Rofental (1891–3772 m a.s.l., Ötztal Alps, Austria). The data sets are spanning a period of 150 years and hence represent a unique, worldwide unprecedented pool of high mountai...

A physically based hydroclimatological model (AMUNDSEN) is used to assess future climate change impacts on the cryosphere and hydrology of the Ötztal Alps (Austria) until 2100. The model is run in 100 m spatial and 3 h temporal resolution using in total 31 downscaled, bias-corrected, and temporally disaggregated EURO-CORDEX climate projections for...

This article presents analyses of retrospective seasonal forecasts of snow accumulation. Re-forecasts with 4 months lead time from two coupled atmosphere-ocean general circulation models (NCEP CFSv2 and MetOffice GloSea5) drive the Alpine Water balance and Runoff Estimation model (AWARE) in order to predict mid-winter snow accumulation in the Inn h...

Mountainous river basins with snow- and glacier-melt dominated runoff regimes are commonly referred to as ‘water towers’. This term strikingly acknowledges the fact that the seasonal release of melt water is also relevant for downstream communities outside mountainous regions. Due to increasing temperatures in the last decades, the seasonal snow co...

Die Gletscher und die saisonale Schneedecke der Alpen sind wichtige Süßwasserreservoirs Europas und speichern enorme Wassermengen in Form von Eis und Schnee. Vor allem in den hochgelegenen Kopfeinzugsgebieten hängt die Wasserbilanz somit stark von den Schwankungen der saisonalen Schneedecke und der Gletscherschmelze ab. Als Folge der Klimaveränderu...

Seasonal predictions aim at forecasting meteorological quantities for the upcoming months and are analysed as monthly data in many cases due to the uncertainties involved. The skill of seasonal predictions is, however, not distributed homogeneously in space and time. While good model skill measures can be achieved for El Niño and the tropics, the s...

Fluctuations of glacier and snow runoff play a key role in water management of alpine catchments. Consequently, the catchment water balance is strongly influenced by the variability of the seasonal snow cover and the glacier melt. The huge water storages enable a shift of the hydrological response of glaciers across time scales, leading to response...

Assessing the amount of water resources stored in mountain catchments as snow and ice as well as the timing of meltwater production and the resulting streamflow runoff is of high interest for glaciohydrological investigations and hydropower production. Quantifications of the uncertainties included in predictions of future runoff regimes are important...

The water balance in forested mountainous catchments is strongly influenced by the interaction of snow and vegetation. Especially coniferous forest canopies have a large storage capacity for snow, exceeding the one for rain by one order of magnitude. The snow intercepted by the trees is exposed to increased turbulence. Hence, the sublimation of int...

Over the last two decades many empirical and physically based models have been developed to predict the seasonal evolution of the snow cover on the ground. Multimodel frameworks support investigations of the performance of snow models with varying complexity, as well as the uncertainty and availability of forcing data propagating through those mode...

Zusammenfassung Saisonale Vorhersagen von meteorologischen Variablen liefern eine Tendenz für die kommende Saison und werden wegen der damit verbundenen Unsicherheiten meistens in Form von Monatswerten analy-siert. In diesem Beitrag wird eine systematische Untersuchung von Hindcasts (retrospektive Prognosen) von zwei verschiedenen gekoppelten Atmos...

Im Rahmen des interdisziplinären Forschungsprojekts STELLA (STorylines of socio-Economic and climatic drivers for Land use and their hydrologicaL impacts in Alpine catchments) wird ein interdisziplinärer Ansatz verfolgt, um die komplexen Wechselwirkungen von Klima, Gesellschaft und Landnutzungsänderung integrativ zu untersuchen und zu quantifiziere...

The mountain cryosphere is recognized to have important impacts on a range of environmental processes. This paper reviews current knowledge on snow, glacier, and permafrost processes, as well as their past, current and future evolution in mountain regions in mainland Europe. We provide a comprehensive assessment of the current state of cryosphere r...

Seasonal snow cover is an important temporary water storage in high-elevation regions. Especially in remote areas, the available data are often insufficient to accurately quantify snowmelt contributions to streamflow. The limited knowledge about the spatiotemporal variability of the snowmelt isotopic composition, as well as pronounced spatial varia...