A5056858365- Meteorological Phenomena and Simulations
- Climate variability and models
- Hydrology and Drought Analysis
- Precipitation Measurement and Analysis
- Wind and Air Flow Studies
- Atmospheric aerosols and clouds
- Atmospheric and Environmental Gas Dynamics
- Plant Water Relations and Carbon Dynamics
- Geophysics and Gravity Measurements
- Image and Signal Denoising Methods
- Tropical and Extratropical Cyclones Research
- Cryospheric studies and observations
- Oceanographic and Atmospheric Processes
- Soil Moisture and Remote Sensing
- Spatial and Panel Data Analysis
- Solar and Space Plasma Dynamics
- Soil Geostatistics and Mapping
- Advanced Image Fusion Techniques
- Ionosphere and magnetosphere dynamics
- GNSS positioning and interference
- Energy Load and Power Forecasting
- Probabilistic and Robust Engineering Design
- Greenhouse Technology and Climate Control
- Fluid Dynamics and Turbulent Flows
- Flood Risk Assessment and Management
University of Bonn
2016-2025
Potsdam Institute for Climate Impact Research
2024
Centre for Higher Education
2022
German Sport University Cologne
2015
Sorbonne Université
2003-2009
Institut de Recherche pour le Développement
2009
Centre National de la Recherche Scientifique
2009
National Institute of Meteorology
2006
The last decade has seen the success of stochastic parameterizations in short-term, medium-range and seasonal forecasts: operational weather centers now routinely use parameterization schemes to better represent model inadequacy improve quantification forecast uncertainty. Developed initially for numerical prediction, inclusion not only provides estimates uncertainty, but it is also extremely promising reducing longstanding climate biases relevant determining response external forcing. This...
Abstract. Probability distributions of multivariate random variables are generally more complex compared to their univariate counterparts which is due a possible nonlinear dependence between the variables. One approach this problem use copulas, have become popular over recent years, especially in fields like econometrics, finance, risk management, or insurance. Since newly emerging field includes various practices, controversial discussion, and vast literature, it difficult get an overview....
Large‐eddy simulations (LES) with the new ICOsahedral Non‐hydrostatic atmosphere model (ICON) covering Germany are evaluated for four days in spring 2013 using observational data from various sources. Reference established Consortium Small‐scale Modelling (COSMO) numerical weather prediction and further standard LES codes performed used as a reference. This comprehensive evaluation approach covers multiple parameters scales, focusing on boundary‐layer variables, clouds precipitation. The...
Atmospheric reanalyses covering the European region are mainly available as part of relatively coarse global reanalyses. The aim this article is to present development and evaluation a next generation regional reanalysis for CORDEX EUR‐11 domain with horizontal grid spacing approximately 6 km. In context, understood be an assimilation heterogeneous observations physical model such numerical weather prediction (NWP) model. system presented here based on NWP COSMO by German Meteorological...
Abstract. We review work on extreme events, their causes and consequences, by a group of European American researchers involved in three-year project these topics. The covers theoretical aspects time series analysis value theory, as well the deterministic modeling via continuous discrete dynamic models. applications include climatic, seismic socio-economic along with prediction. Two important results refer to (i) complementarity spectral terms part its power spectrum; (ii) need for coupled...
Abstract Statistical methods to bias correct global or regional climate model output are now common get data closer observations in distribution. However, most correction (BC) work for one variable and location at a time basically reproduce the temporal structure of models. The intervariable, spatial, dependencies corrected usually poor compared observations. Here, authors propose novel method multivariate BC. empirical copula–bias (EC–BC) combines one-dimensional BC with shuffling technique...
More than one hundred days were simulated over very large domains with fine (0.156 km to 2.5 km) grid spacing for realistic conditions test the hypothesis that storm (kilometer) and large-eddy (hectometer) resolving simulations would provide an improved representation of clouds precipitation in atmospheric simulations. At scales resolve convective storms (storm-resolving short), vertical velocity variance becomes resolved a better physical basis is achieved representing precipitation....
A 1000-yr integration of a coupled ocean–atmosphere model (ECHO-G) has been analyzed to describe decadal multidecadal variability in equatorial Pacific sea surface temperature (SST) and thermocline depth (Z20), their relationship modulations El Niño–Southern Oscillation (ENSO) behavior. Although the is characterized by an unrealistically regular 2-yr ENSO period, it exhibits significant amplitude on time scales. The authors' main finding that structures SST Z20 characteristic tropical (TPDV)...
Abstract A statistical downscaling approach for extremes using censored quantile regression is presented. Conditional quantiles of station data (e.g., daily precipitation sums) in Germany are estimated by means the large-scale circulation as represented NCEP reanalysis data. It shown that a mixed discrete–continuous response variable, such sum, can be statistically modeled variable. Furthermore, conditional skill score formulated to assess relative gain forecast compared with reference...
Predictions of the uncertainty associated with extreme events are a vital component any prediction system for such events. Consequently, ought to be probabilistic in nature, predictions taking form probability distributions. This paper concerns systems where data assumed follow either generalized value (GEV) distribution or Pareto distribution. In this setting, properties proper scoring rules that facilitate assessment investigated, and closed expressions continuous ranked score (CRPS)...
This study expands the pool of verification methods for probabilistic weather and climate predictions by a decomposition quantile score (QS). The QS is proper function evaluates predictive quantiles on set forecast–observation pairs. We introduce in reliability, resolution uncertainty discuss biases decomposition. Further, reliability diagram forecasts presented. Verification with its illustrated precipitation derived from mesoscale prediction ensemble COSMO-DE-EPS German Meteorological...
Distinguishing between direct and indirect connections is essential when interpreting network structures in terms of dynamical interactions stability. When constructing networks from climate data the nodes are usually defined on a spatial grid. The edges derived bivariate dependency measure, such as Pearson correlation coefficients or mutual information. Thus, indistinguishably represent dependencies. Interpreting fields realizations Gaussian Random Fields (GRFs), we have constructed...
To improve the forecasts of weather extremes, we propose a joint spatial model for observations and forecasts, based on bivariate Brown-Resnick process. As class stationary processes is fully characterized by pseudo cross-variograms, contribute to theorical understanding cross-variograms refining knowledge asymptotic behaviour all their components introducing parsimonious, but flexible parametric model. Both findings are interest in classical geostatistics own. The proposed applied real...
Abstract The primary objective of the GRACE Follow‐On satellite mission is to measure temporal changes in Earth's gravitational field. Distance variations between two GRACE‐FO satellites, recorded by a K‐Band Ranging system and new Laser Interferometer (LRI), are significantly influenced atmospheric mass redistribution. We investigate whether sub‐monthly water mass, precipitation, total storage during extreme flood event western Europe 2021 were sufficiently large influence gravity field...
Abstract. Europe frequently experiences a wide range of extreme events and natural hazards, including heatwaves, precipitation, droughts, cold spells, windstorms, storm surges. Many these do not occur as single but rather show multivariate character, known compound events. We investigate the interactions between weather events, their characteristics, changes in intensity frequency, well uncertainties past, present, future. also explore impacts on various socio-economic sectors Germany...
This study assesses the detectability of external influences in changes precipitation extremes twentieth century, which is explored through a perfect model analysis with an ensemble coupled global climate (GCM) simulations. Three indices are defined from generalized extreme value (GEV) distribution: 20-year return (P 20), median m), and cumulative probability density as probability-based index (PI). Time variations area-averages these three analyzed over different spatial domains globe to...
1 Kinetic energy spectra derived from commercial aircraft observations of horizontal wind 2 velocities exhibit a k−5/3 wavenumber dependence on the mesoscale that merges into 3 k−3 macroscale. In this study, spectral analysis is applied to evalu4 ate ensemble prediction system using convection-permitting NWP model 5 COSMO-DE (COSMO-DE-EPS). One-dimensional kinetic en6 ergy are zonal and meridional velocities, as well vertical velocities. 7 Besides general evaluation, reveal important...
Abstract Statistical postprocessing is an integral part of ensemble prediction system. This study compares methods used to derive probabilistic quantitative precipitation forecasts based on the high-resolution version German-focused Consortium for Small-Scale Modeling (COSMO-DE) time-lagged (COSMO-DE-TLE). The investigation covers period from July 2008 June 2011 a region over northern Germany with rain gauge measurements 445 stations. investigated provide pointwise estimates predictive...
The spatial variability of wind gusts is probably as large that precipitation, but the observational weather station network much less dense. lack an area-wide analysis hampers forecast verification gust warnings. This article develops and compares several approaches to derive a probabilistic for Germany. Such provides probability exceeds certain warning level. To end we have 5 years observations hourly maxima at about 140 stations German service our disposal. are based on linear statistical...
Potential vorticity (PV) and its conservation principle elegantly describe large-scale atmospheric dynamics. On the mesoscale, however, PV has received less attention. We characteristics of on convective weather scale (≈10 km) as simulated by non-hydrostatic numerical prediction model COSMO-DE. Two cases with a different synoptic background are analysed, 5 June 2011 22 2011. Composites other quantities like wind velocity around storm updrafts calculated to test consistency anomalies...
Abstract. Doppler wind lidars (DWLs) have increasingly been used over the last decade to derive mean in atmospheric boundary layer. DWLs allow determination of vector profiles with high vertical resolution and provide an alternative classic meteorological tower observations. They also receive signals from altitudes higher than a can be set up flexibly any power-supplied location. In this work, we address question whether how gusts derived DWL The characterization is one central goal Field...