Radar Forward Operator for Verification of Cloud Resolving Simulations within the COSMO Model


Book Description

In this work, various simulation methods of the effective radar reflectivity factor and its attenuation by atmospheric particles from the variables of the COSMO model have been implemented within a so-called radar forward operator, and its output was compared to measurements from the German radar network. To perform a statistically reliable model verification, contoured frequency by altitude diagrams (CFADs) were used and refined.




Precipitation Science


Book Description

Precipitation Science: Measurement, Remote Sensing, Microphysics and Modeling addresses the latest key concerns for researchers in precipitation science, mainly observing, measuring, modeling and forecasting. Using case studies and global examples, the book demonstrates how researchers are addressing these issues using state-of-the-art methods and models to improve accuracy and output across the field. In the process, it covers such topics as discrepancies between models and observations, precipitation estimations, error assessment, droplet size distributions, and using data in forecasting and simulations. Other sections cover improved standard approaches, novel approaches, and coverage of a variety of topics such as climatology, data records, and more. By providing comprehensive coverage of the most up-to-date approaches to understanding, modeling, and predicting precipitation, this book offers researchers in atmospheric science, hydrology and meteorology with a comprehensive resource for improving outcomes and advancing knowledge. Provides updated and novel approaches to key issues in precipitation research Offers practical knowledge through global examples and case studies Includes full-color visuals to enhance comprehension of key concepts




Convective precipitation simulated with ICON over heterogeneous surfaces in dependence on model and land-surface resolution


Book Description

The impact of land-surface properties like vegetation, soil type, soil moisture, and the orography on the atmosphere is manifold. These features determine the evolution of the atmospheric boundary layer, convective conditions, cloud evolution and precipitation. The impact of model grid spacing and land-surface resolution on convective precipitation over heterogeneous surfaces is investigated using ICOsahedral Nonhydrostatic (ICON) simulations within the framework of the HD(CP)2 project.




Arctic mixed-phase clouds : Macro- and microphysical insights with a numerical model


Book Description

This work provides new insights into macro- and microphysical properties of Arctic mixed-phase clouds: first, by comparing semi-idealized large eddy simulations with observations; second, by dissecting the influences of different surface types and boundary layer structures on Arctic mixed- phase clouds; third, by elucidating the dissipation process; and finally by analyzing the main microphysical processes inside Arctic mixed-phase clouds.




Optimizing Dual-Doppler Lidar Measurements of Surface Layer Coherent Structures with Large-Eddy Simulations


Book Description

Coherent structures are patterns in the wind field of the atmospheric boundary layer. The deployment of two scanning Doppler lidars facilitates the measurement of the horizontal wind field, but the inherent averaging processes complicate an interpretation of the results. To assess the suitability of this technique for coherent structure detection large-eddy simulations are used as a basis for virtual measurements, and the effects of the lidar technique on the wind field structure are analyzed.




Assessing the Aerosol Impact on Southern West African Clouds and Atmospheric Dynamics


Book Description

By using COSMO-ART, highly resolved process study simulations for 2-3 July 2016 are conducted to assess the aerosol effect on the meteorological conditions of southern West Africa. The meteorological phenomenon Evening Monsoon Flow Enhancement (EMFE) is identified as highly susceptible to the aerosol direct effect, leading to a spatial shift of the EMFE front. In a second aerosol feedback chain the aerosol variation leads to a temporal shift of the stratus-to-cumulus transition.




Representation of warm conveyor belts in sub-seasonal forecast models and the link to Atlantic-European weather regimes


Book Description

This study systematically investigates the representation of warm conveyor belts (WCBs) in large reforecast data sets of different numerical weather prediction models and evaluates the role of WCBs for the onset and life cycle of Atlantic-European weather regimes. The results emphasize the importance of accurate forecast of WCBs for sub-seasonal prediction on time scales beyond two weeks and tie the low forecast skill of blocked weather regimes over Europe to misrepresented WCBs.




Boundary-Layer Processes Producing Mesoscale Water-Vapour Variability over a Mountainous Island


Book Description

Over complex terrain, spatial inhomogeneities of pre-convective atmospheric conditions occur due to convection and mesoscale transport processes. This thesis focuses on the identification of these processes over the mountainous island of Corsica and on the evaluation of their impact on the spatial variability of water vapour, convection-related parameters and the evolution of deep convection by means of observations.




Objective identification and climatology of mesoscale high-wind features within extratropical cyclones


Book Description

Strong winds accompanying extratropical cyclones are commonly associated with various mesoscale features. This work introduces RAMEFI (RAndom-forest-based Mesoscale wind Feature Identification), an objective and flexible identification approach based on key surface characteristics to distinguish these features. RAMEFI is further applied to compile a climatology over Europe, offering a comprehensive analysis of feature frequency, distribution, and characteristics.




Wind Systems and Energy Balance in the Dead Sea Valley


Book Description

A new measurement concept was developed to determine the amount, variability and governing factors of evaporation from the Dead Sea. Additionally, a suitable indirect method to calculate evaporation is presented. Results show that vapour pressure deficit and wind speed are governing evaporation and that the diurnal cycle is determined by three distinct diurnal wind systems. The occurrence frequency and intensity of the wind systems are determined by local differential cooling and heating.