Swiss Federal Office of Meteorology and Climatology

Zürich, Switzerland

Swiss Federal Office of Meteorology and Climatology

Zürich, Switzerland
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Rheinberger C.M.,French National Institute for Agricultural Research | Romang H.E.,Swiss Federal Office of Meteorology and Climatology | Brundl M.,WSL Institute for Snow and Avalanche Research SLF
Natural Hazards and Earth System Sciences | Year: 2013

Quantitative risk assessments of debris flows and other hydrogeological hazards require the analyst to predict damage potentials. A common way to do so is by use of proportional loss functions. In this paper, we analyze a uniquely rich dataset of 132 buildings that were damaged in one of five large debris flow events in Switzerland. Using the double generalized linear model, we estimate proportional loss functions that may be used for various prediction purposes including hazard mapping, landscape planning, and insurance pricing. Unlike earlier analyses, we control for confounding effects of building characteristics, site specifics, and process intensities as well as for overdispersion in the data. Our results suggest that process intensity parameters are the most meaningful predictors of proportional loss sizes. Cross-validation tests suggest that the mean absolute prediction errors of our models are in the range of 11%, underpinning the accurateness of the approach. © 2013 Author(s).

Kaurola J.,Finnish Meteorological Institute | Lindfors A.,Finnish Meteorological Institute | Lindfors A.,University of Edinburgh | Lakkala K.,Finnish Meteorological Institute | And 5 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2010

Erythemal daily UV doses have been calculated using input data from the ERA-40 reanalysis for years 1958-2002. The quality of input parameters for UV calculations has been validated with available ground based total ozone data and estimates of Cloud Modification Factor (CMF), and the results have been compared with existing UV data. Owing to limited availability of validation data especially during 1960s and 1970s the analysis focused on sites located in central and northern Europe. The current work is the first step in deriving reliable long-term UV time series from the ERA-40 reanalysis. Total ozone from the ERA-40 reanalysis is affected by significant biases, especially before satellite ozone measurements were available for assimilation. Estimations of the effect of clouds on surface UV were made using global radiation (300-3000 nm) budgets at the surface because available ERA-40 cloud data do not allow good estimates of surface daily UV doses. There are some problems with ERA-40 solar radiation budgets which cause systematic biases in calculated daily UV doses. Comparison of calculated daily erythemal UV doses against ground-based UV data indicate that ERA-40 UV doses are typically overestimated by 6-18% in central and northern Europe and underestimated by 9-17% at Davos, Switzerland. Root-mean-square errors of the calculated daily UV doses are usually in the range of 30-40%. Trends of UV doses were calculated for the concurrent period of the TOMS satellite UV data (1979-2002). The trends of zonally averaged ERA-40 and TOMS UV agree well and are mostly of the same sign and magnitude. Copyright 2010 by the American Geophysical Union.

Manjunatha A.P.,ABB | Korba P.,University of Zürich | Stauch V.,Swiss Federal Office of Meteorology and Climatology
2013 IEEE Grenoble Conference PowerTech, POWERTECH 2013 | Year: 2013

This paper describes the development and implementation of a method and a prototype solving the problem of optimal integration of the largest battery energy storage system installed so far in Switzerland into an existing power grid in presence of intermittent renewable energy sources. The developed approach is based on model-based predictive control, a well-known method in process automation. Mathematical models of all involved system components, such as local load or weather dependent power generation profiles, were developed. In addition, plant-model uncertainties are handled by an additional fast corrective feedback control loop. The result, an advanced battery controller, has been implemented in cooperation with ABB Ltd. in a real-time prototype and integrated into the existing energy management system used for the manual operation and control of the real 1MW Li-Ion battery installed by the electric power utility of the canton of Zurich (EKZ) in Switzerland. The newly developed functions include automatic peak-shaving and cost optimal battery control subject to time-varying energy prices and predefined physical and operating limits. © 2013 IEEE.

Foresti L.,Center for Australian Weather and Climate Research | Panziera L.,Swiss Federal Office of Meteorology and Climatology | Mandapaka P.V.,Nanyang Technological University | Germann U.,Swiss Federal Office of Meteorology and Climatology | Seed A.,Center for Australian Weather and Climate Research
Meteorological Applications | Year: 2015

An analogue-based approach for nowcasting the spatio-temporal evolution of orographic rainfall at the southern side of the Swiss Alps, NORA, was developed by Panziera etal. (2011). Analogues were found by retrieving a set of similar mesoscale situations and rainfall fields, and the forecast was given by the evolution of the precipitation observed after the analogues. This strategy avoids the explicit space-time rainfall simulation to obtain ensembles that characterize the forecast uncertainty. In this study the choice of the most similar rainfall fields is further explored by means of principal components analysis. The latter is used to represent the sequences of radar images in a phase space constructed with a low number of principal components. The principal components explain the main patterns which characterize the spatial distribution of rainfall, a feature that was not implemented in the original NORA. The alternative version of the nowcasting tool is described and the forecasts are verified in detail. Due to the ability to represent forecast uncertainty, the ensemble prediction system has superior value for probabilistic short-term forecasting compared to Eulerian persistence, which is more suited for deterministic forecasts. It is also demonstrated that retrieving similar sequences of images instead of single images does not improve forecast skill, which leads to the conclusion that the past trend in rainfall evolution is not a good predictor of its future evolution. © 2015 Royal Meteorological Society.

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