A5045672612- Tropical and Extratropical Cyclones Research
- Climate variability and models
- Meteorological Phenomena and Simulations
- Ocean Waves and Remote Sensing
- Oceanographic and Atmospheric Processes
- Cryospheric studies and observations
- Cocoa and Sweet Potato Agronomy
- Wind and Air Flow Studies
- Atmospheric and Environmental Gas Dynamics
- Experimental and Theoretical Physics Studies
- advanced mathematical theories
- Ecology, Conservation, and Geographical Studies
- Flood Risk Assessment and Management
- Urban Heat Island Mitigation
- Methane Hydrates and Related Phenomena
- Interdisciplinary Research and Collaboration
- Atmospheric aerosols and clouds
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Integrated Energy Systems Optimization
- Structural Analysis and Optimization
- demographic modeling and climate adaptation
- Land Use and Ecosystem Services
- Plant responses to water stress
- Scientific Research and Discoveries
German Climate Computing Centre
2021-2024
Climate Service Center
2021-2024
Fischer (Germany)
2024
Helmholtz-Zentrum Hereon
2023
Karlsruhe Institute of Technology
2023
Universität Hamburg
2001-2021
Impact
2012-2014
Clinical Research Organization
2010-2011
Max Planck Society
2009
Max Planck Institute for Meteorology
2009
Abstract Here we present the first multi-model ensemble of regional climate simulations at kilometer-scale horizontal grid spacing over a decade long period. A total 23 run with $$\sim $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>∼</mml:mo> </mml:math> 3 km, driven by ERA-Interim reanalysis, and performed 22 European research groups are analysed. Six different models (RCMs) represented in ensemble. The compared against available high-resolution precipitation...
Abstract Taking advantage of a large ensemble Convection Permitting‐Regional Climate Models on pan‐Alpine domain and an object‐oriented dedicated analysis, this study aims to investigate future changes in high‐impact fall Mediterranean Heavy Precipitation Events at high warming levels. We identify robust multi‐model agreement for increased frequency from central Italy the northern Balkans combined with substantial extension affected areas, dominant influence driving Global projecting...
Taking advantage of a large ensemble Convection Permitting-Regional Climate Models on pan-Alpine domain and an object-oriented dedicated analysis, this study aims to investigate future changes in the high-impact fall Mediterranean Heavy Precipitation Events at high warming levels. We identify robust multi-model agreement for increased frequency from central Italy northern Balkans combined with substantial extension affected areas, dominant influence driving Global projecting frequency,...
&lt;p&gt;Here we present the first multi-model ensemble of climate simulations at kilometer-scale horizontal resolution over a decade long period. A total 22 simulations, performed by 21 European research groups are analyzed. Six different regional models (RCMs) represented in ensemble. The compared against available high-resolution precipitation observations and coarse (12 km) RCMs with parameterized convection. model respect to mean precipitation, intensity frequency, heavy on...
Since the 1980s, industrialization and urbanization of Beijing area has entered a period high-speed growth. This paper asks question: How have such great changes in urban land-use over past decades impacted precipitation? In this study, we investigate analyze effects on summer precipitation using numerical modeling approaches. Applying mesoscale atmospheric model METRAS, determine impact surface cover 13 heavy events. We implement five idealized scenarios: Reference scenario, No-urban...
Abstract A storm track is simulated in a coarse‐resolution multilevel primitive‐equation model with linear surface friction and heating terms. restoration temperature distribution consisting of dipole embedded zonally symmetric profile forces the to simulate heating. Three simulations, each different orientation, are performed test sensitivity storm‐track organization external forcing field. The climatological time‐mean circulation transient disturbances reference simulation agree well...
Control mechanisms of tropical cyclone size are investigated with the axisymmetric cloud model HURMOD. In agreement preceding HURMOD studies, results exhibit existence a fixed‐point attractor associated cyclone. From non‐dimensionalized equations, similarity law is derived, which relates six parameters to horizontal extent in steady state. Each parameter one following processes: planetary rotation, condensation time‐scale, radiative relaxation diffusion, vertical and surface transfer....
Abstract The assumption of gradient wind balance is customarily made so as to derive the theoretical upper-bound intensity a mature tropical cyclone. Emanuel's theory hurricane potential (E-PI) makes use this assumption, whereas more recent studies by Bryan and Rotunno demonstrate that effect unbalanced flow can result in maximum winds are well excess E-PI (superintensity). existence supergradient has been verified slab boundary layer model developed Smith. Here, authors apply within...
Abstract The local mass balance equations of cloudy air are formulated for a model system composed dry air, water vapor, and four categories condensate particles, as typically adopted numerical weather prediction climate models. choice the barycentric velocity reference motion provides most convenient form total continuity equation. Mass transfer across earth’s surface due to precipitation evaporation causes nonvanishing vertical ws is proportional difference between rate rain plus snow...
Tropical cyclone dynamics is investigated by means of a conceptual box model. The tropical (TC) divided into three regions, the eye, eyewall and ambient region. model forms low-order dynamical system ordinary differential equations. These are based on entropy budget equations comprising processes surface enthalpy transfer, advection, convection radiative cooling. For ocean parameter settings, possesses four non-trivial steady state solutions when sea temperature (SST) above critical value....
This study addresses the role of convective available potential energy (CAPE) in intensification simulated tropical cyclones. Additionally, it also examines 'wind-induced surface heat exchange' (WISHE) theory which CAPE is non-existent during intensification. We use a hierarchy models with different complexity. A low-order cyclone model forms simplest model. It found that damping by fast exchange as assumed WISHE inhibits substantial result can be explained dominance secondary circulation...
Abstract In order to estimate the role of latent cooling processes for tropical cyclones, we have performed sensitivity simulations with both axisymmetric cloud‐resolving model HURMOD and fully three‐dimensional COSMO German Weather Service. As an idealised initial state, a convectively unstable vortex superimposed entropy anomalies has been assumed. While growth rate maximum wind speeds become unnaturally large in without processes, presence these proves be necessary maintain convection...
The problem of zonal jet formation and cyclone–anticyclone asymmetry in decaying rotating turbulence is addressed using both laboratory experiments numerical simulations with a high-resolution shallow water model spherical geometry. Experiments are performed at different Rossby Froude numbers applying rigid wall as meridional boundary the scheme to mimic experimental apparatus. zonally banded flow pattern, i.e. meridionally confined easterly/westerly jets, has observed; results confirmed...
Abstract The WISHE (wind‐induced surface heat exchange) instability theory for tropical atmospheric disturbances suggests that maximum warming occurs at the position of wind. Applying this concept to axisymmetric cyclones leads outward migration radius wind without amplification. Therefore, fundamental feedback loop cannot explain cyclogenesis on its own. Additional restrictions surface‐flux‐induced heating are necessary. This study investigates in detail effect such within framework a...
Abstract Emanuel’s theory of hurricane potential intensity (E-PI) makes use the assumption that slantwise convective instability vanishes in a steady-state vortex tropical cyclone. In framework an extended mathematical model it is shown relaxing this and including eye results larger maximum wind speed compared to predictions made by E-PI. Previous studies Bryan Rotunno demonstrate effect unbalanced flow considerably contributes winds excess E-PI (“superintensity”). The authors argue proposed...
Abstract This paper addresses the validity of gradient wind balance approximation during intensification phase a tropical cyclone in Ooyama’s three-layer model. For this purpose, sensitivity to various model modifications is examined, given by inclusion (i) unbalanced dynamics free atmosphere, (ii) slab boundary layer, (iii) height-parameterized layer model, and (iv) rigid lid. The most rapid occurs when employs while simulation with balanced reveals slowest intensification. realistic...
Abstract Threefold densities may be introduced into atmospheric thermodynamics. For rainless clouds the general indirect or implicit conclusion is that they are denser than moist air under same circumstances, although in a classic treatise different was reached, to effect cloudy (containing water and/or ice) less dense pressure and temperature. By reconsidering carefully ways of determining densities, any doubts linger after reading scant literature dealing explicitly with density cloud dispelled.
This paper presents an atmospheric axisymmetric balanced model for a zero potential vorticity vortex that is vertically confined between two frictional boundary layers. Zero has the consequence temperature does not vary on angular momentum surfaces. leads to neutrality with respect symmetric instability. The conserves this flow property when diabatic heating and torque also do With these conditions transformation radius coordinates, reduces prognostic equations physical radii at lower upper...
The barotropic instability of finite amplitude waves is suggested as a mechanism for explaining the equilibration baroclinic wave growing in meridionally independent vertical shear flow. A quasigeostrophic two-layer channel model on an f-plane used to give evidence this hypothesis. Three solutions with different flow symmetries are adopted analysis. Numerical simulations reveal that symmetry initial small perturbation can have large impact structure evolution and energetics. first solution...
Wind energy has become one of the most important mitigation options for climate change over last decades. However, variability and availability wind are also expected to be changed due change. For this purpose, KliWiSt project been initiated determine influence on site assessments in Germany. Within scope project, many aspects impacts have studied uncertainties about topic develop recommendations actions. Although there studies literature which evaluate effects upcoming decades, low events...
Abstract In this study, climate model simulations are evaluated with regard to the wind energy resource in Germany. Since accurate determination of local requires a high resolution, we consider Convection Permitting Regional Climate Models (CP-RCMs) 3km resolution. We analysed RCP8.5 scenario carried out i) within EUCP project using RCM REMO convection permitting mode for Central European domain (CEU-3) and ii) CORDEX FPS-Convection that provides ensemble CP-RCMs Pan-Alpine region (ALP-3)....
Abstract The response of tropical cyclone activity in the predicted warmer future climate is still a topic scientific research. However, by nonlocality hypothesis, depends rather on relative than absolute sea surface temperature (SST). This hypothesis investigated through idealized experiments performed with global atmospheric model PlaSim. includes prescribed SST and adopts spectral resolution T170 for resolving cyclones. An land‐sea configuration two oceans continents has been used to...
The dynamical system behaviour of tropical cyclones and their potential intensity with a view to sea surface temperature, tropospheric temperature stratification moisture content is investigated in the axisymmetric convective model HURMOD. results exhibit existence fixed-point attractor associated strong cyclone. Moreover, initial vortex strength forms an amplitude threshold cyclogenesis. Above this threshold, size cyclone its are independent horizontal extent. Below cyclogenesis does not...