Evaluating the improvements of the BOLAM model of the ISPRA Sistema Idro-Meteo-Mare on the December 2008 flood event in Rome

M Casaioli,B Lastoria,M Bussettini,S Mariani

doi:10.5194/adgeo-25-135-2010

M Casaioli, B Lastoria + Show 2 more

Open Access

https://doi.org/10.5194/adgeo-25-135-2010

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Abstract

Abstract. The Sistema Idro-Meteo-Mare is an integrated meteo-marine forecasting chain for the Mediterranean basin. The recent update of the meteorological segment, based on the hydrostatic BOlogna Limited Area Model (BOLAM), gives the opportunity for a comparative verification study on a Mediterranean cyclone. The 10–12 December 2008 flood event in Rome has been chosen as case study. This disastrous event was claimed to be an extreme one by mass-media; however, its return time is shown here to be about 5 years. The Mediterranean cyclone responsible for the flood offers a tough case study in order to verify the model's ability in reproducing the evolution of meso-synoptic features in the Mediterranean environment. A qualitative comparison, employing satellite data and derived products, is performed. Results suggest that the upgraded model provides a more realistic representation of the cyclone warm sector – where the main rainfall peak took place – whereas the error in the cyclone trajectory and shape evolution is less affected by the BOLAM improvement.

Highlights

Mediterranean weather is characterized by a complex phenomenology, involving the interaction of synoptic-scale patterns with local forcing, including orography, moist processes, and sea/land distribution
These motivations drove in the late nineties the development of an integrated meteo-marine forecasting chain (Speranza et al, 2004, 2007), named Sistema Idro-MeteoMare (Hydro-Meteo-Marine Forecasting System – hereinafter SIMM), at the former Dipartimento dei Servizi Tecnici Nazionali of Presidenza del Consiglio dei Ministri (Department of National Technical Services of the Italian Cabinet Presidency), part of the Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA – Institute for Environmental Protection and Research)
SIMM, which runs operationally since 2000, is formed by a cascade of four numerical models, telescoping from the Mediterranean basin to the Venice Lagoon, and initialized by means of analyses and forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF). Such integrated system consists of a meteorological model, the parallel version of the hydrostatic BOlogna Limited Area Model (BOLAM), running at 10 km over the whole Mediterranean basin, coupled over the Mediterranean Sea with the WAve Model (WAM), a high-resolution shallow-water model of the Adriatic and Ionian Sea, namely the Princeton Ocean Model (POM), and a finite-element shallow-water model on the Venice Lagoon (VL-FEM)

Summary

Introduction

Mediterranean weather is characterized by a complex phenomenology, involving the interaction of synoptic-scale patterns with local forcing, including orography, moist processes, and sea/land distribution. Not suitable for quantitative verification, this product provides a valid qualitative reference for diagnosis and forecast verification of space-time rainfall patterns, at least for convective precipitation (Heinemann and Kerenyi, 2003).

Results

Conclusion