Description: Das Projekt "Upscale Error Growth - A4: Evolution and predictability of storm structure during extratropical transition of tropical cyclones" wird vom Umweltbundesamt gefördert und von Johannes Gutenberg-Universität Mainz, Institut für Physik der Atmosphäre durchgeführt. Predictability of midlatitude weather systems is frequently compromised by tropical cyclones that undergo extratropical transition (ET) in the far upstream region. This loss in predictability has its origin in uncertainties in the evolution of the ET system itself. These uncertainties ultimately project onto midlatitude Rossby-wave trains and may affect a near-hemispheric region. This project will investigate a specific part of this upscale growth, namely how uncertainties in the deep convection of the ET system amplify and project onto structural changesMoist convection is an atmospheric process whose initiation depends both on the synoptic-scale weather situation and local forcing. In weather situations characterized by weak synoptic-scale forcing, local characteristics (e.g. land surface variability) are more likely to be significant in the initiation of convective precipitation. Current state of the art numerical weather prediction (NWP) models still have a limited representation of terrestrial hydrological processes, particularly with respect to soil moisture and lateral terrestrial water flows. In the same time these NWP models are known for their limited forecast quality during weak synoptic-scale forcing conditions, which could be related to a larger contribution of unresolved land-atmosphere coupling processes in such weather situations. In this project we will investigate which improvements in convective precipitation predictability can be achieved by a more sophisticated treatment of terrestrial hydrological processes in NWP models. To reach this objective we will simulate a panel of joint case-studies in Germany and West Africa using the Weather Research and Forecasting (WRF) model, a hydrologically enhanced version of WRF, namely WRF-Hydro, and the Consortium of Small-scale Modeling (COSMO) model. We will then develop methods to quantify the physical processes at stake in soil moisture - precipitation feedback mechanisms, especially for the cases where more complex descriptions of surface and subsurface lateral water flows improve precipitation predictability. Finally, ensemble COSMO simulations will be designed, performed and evaluated. The ensemble will include initial condition uncertainties pertaining to ventilation, as well as uncertainties associated with unresolved processes within the boundary layer and the interaction with the ocean surface. The evolution of ensemble spread will be used to diagnose the growth of uncertainty in more detail. Made possible by collaborations within W2W, we will make first steps into an important, but largely unexplored problem: the relation between the key kinematic information contained in the Lagrangian coherent structures and the dynamics of the underlying time-dependent flow. Future work will continue this exploration and will extend the analysis of the upscale growth in the ensemble framework. (abridged text)
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Mainz ? Hurrikan ? Klimatologie ? Meteorologie ? Pflanzensamen ? Aufbereitungstechnik ? Regenwasser ? Prognose ? Wetterdaten ? Sturm ? Atmosphärische Wissenschaften ? Evolution ? Fallstudie ? Wasserströmung ? Lüftung ? Meeresoberfläche ? Prognosemodell ? Simulation ? Stand der Technik ? Tropengebiet ? Wettervorhersage ? Bodenfeuchte ? Verwitterung ? Modellierung ? Untergrund ? Afrika ? REACH ? Atmosphärischer Prozess ? Feuchtigkeit ? Forschung ? Physikalischer Vorgang ? Erdoberfläche ? Niederschlag ? Wasseroberfläche ? Wasserstand ? Wetter ? Grenzschicht ? Hydrologie ? Konvektion ? Zeitverlauf ? Unterirdisches Wasser ? Fluss [Bewegung] ?
Region: Rheinland-Pfalz
Bounding box: 7.5° .. 7.5° x 49.66667° .. 49.66667°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2015-07-01 - 2019-06-30
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