Abstract
Due to their rarity and intensity, Mediterranean Tropical-Like Cyclones (TLCs; also known as medicanes) have been a subject of study over the last decades and lately the interest has undoubtedly grown. The current study investigates a well-documented TLC event crossed south Sicily on November 7–8, 2014 and the added value of higher spatial horizontal resolution through a physics parameterization sensitivity analysis. For this purpose, Weather Research and Forecasting model (version 3.9) is used to dynamically downscale ECMWF Re-Analysis (version 5) (ERA5) reanalysis 31 km spatial resolution to 16 km and 4 km, as parent and inner domain, respectively. In order to increase the variability and disparity of the results, spectral nudging was implemented on both domains and the outputs were compared against satellite observations and ground-based stations. Although, the study produces mixed results, there is a clear indication that the increase of resolution benefits specific aspects of the cyclone, while it deteriorates others, based on both ground and upper air analyses. The sensitivity of the parent domain displays an overall weak variability while the simulations demonstrate a positive time-lag predicting a less symmetric cyclone with weak warm core. On the contrary, inner domain analysis shows stronger variability between the model simulations reproducing more distinct clear tropical characteristics with less delayed TLC development for most of the experiments.
Highlights
The Mediterranean basin is an area prone to the generation of low-pressure systems [1].The dominant type is extra-tropical cyclones, fueled by the baroclinic instability due to horizontal temperature gradients
The sensitivity of the Weather Research and Forecasting (WRF) model experiments is presented
Parameterization and the presented separately for (a) parameterization schemes and the discussion focuses on the influence of spatial horizontal resolution on the development and evolution discussion focuses on the influence of spatial horizontal resolution on the development and evolution of the medicane
Summary
The Mediterranean basin is an area prone to the generation of low-pressure systems [1]. A cut-off low in the mid-upper levels of the atmosphere has been detected near several medicanes [4,14] This produces a pool of cold air with high potential vorticity which can enhance instability and deepen the surface pressure depression. Several authors have used limited area models to simulate historical medicanes aiming at a better understanding of the phenomenon or at investigating the capability of numerical weather prediction to capture its occurrence and development This method is considered to have a potential to generate valuable results [20]. Davolio et al 2009 [25] propose the use of a domain large enough and an initiation time early enough to capture the entire formation of the vortex They found that even when the simulation runs on global forecast output, this configuration allows for better results than the usage of more recent output.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
