Analysis of a Mediterranean Tropical-Like Cyclone. Sensitivity to WRF Parameterizations and Horizontal Resolution

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.

Review article: Risk management framework of environmental hazards and extremes in Mediterranean ecosystems

“…More specifically, Matzarakis and Nastos (2011) made an effort to identify heat waves in Athens, Greece, by using the physiologically equivalent temperature (PET), a human thermal index based on the energy balance of the human body. They used consecutive days (three and more) and the duration of each heat wave for PET ≥ 35 • C (the threshold of extreme heat stress; Matzarakis et al, 1999) and T amin ≥ 23 • C (the threshold that represents PET values of thermal neutrality; Nastos and Matzarakis, 2008) in order to quantify the duration of heat waves and their impacts (Fig. 3).…”

“…Tornadoes occur in many parts of the world (Fujita, 1973). Several publications during the last several decades have presented historical records concerning tornadic activity (e.g., Meaden, 1976;Tooming and Peterson, 1995;Peterson, 1998;Reynolds, 1999;Tyrrell, 2003;Macrinoniene, 2003;Dotzek, 2003;Nastos and Matsangouras, 2010;Gayà et al, 2000;Brázdil et al, 2012;Rauhala et al, 2012;Haghroosta et al, 2014). As far as tornadic activity over Greece is concerned, a comprehensive spatial distribution of a total of 612 events (171 tornadoes, 374 waterspouts and 67 funnel clouds) recorded in 405 d was presented (Matsangouras et al, 2014a, b: Nastos and as there were several days with multiplied events within the period 1709-2012 (Fig.…”

“…In a recent study (Mylonas et al, 2019), the higher spatial horizontal resolution of a TLC event, south of Sicily on 7-8 November 2014, through a physics parameterization sensitivity analysis, allows for improved simulations in most setups that were tested in terms of trajectory and TLC structure.…”

Analysis of an Extratropical Cyclone in the Southwest Atlantic: WRF Model Boundary Conditions Sensitivity

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Study on Wind Simulations Using Deep Learning Techniques during Typhoons: A Case Study of Northern Taiwan

“…The WRF model offers two dynamic solvers for computing the atmospheric governing equations: Advanced Research WRF (ARW) solver and Nonhydrostatic Mesoscale Model. Numerous studies on the WRF numerical model with tropical cyclones have been conducted recently [11][12][13][14][15][16]. For instance, Tao et al [17] indicated that WRF is able to capture the amount and location of the observed surface rainfall and that the typhoon-induced circulation, orographic lifting and a moisture-abundant southwest flow are the main mechanisms that together produced the tremendous rainfall.…”