Regional model simulation of the hydrometeorological effects of the Fucino Lake on the surrounding region

B Tomassetti,M Verdecchia,G Visconti,F Giorgi

doi:10.5194/angeo-21-2219-2003

Abstract

Abstract. The drainage of the Fucino Lake of central Italy was completed in 1873, and this possibly caused significant climatic changes over the Fucino basin. In this paper we discuss a set of short-term triple-nested regional model simulations of the meteorological effects of the Fucino Lake on the surrounding region. We find that the model simulates realistic lake-breeze circulations and their response to background winds. The simulations indicate that the lake affects the temperature of the surrounding basin in all seasons and precipitation in the cold season, when cyclonic perturbations move across the region. Some effects of the lake also extend over areas quite far from the Fucino basin. Our results support the hypothesis that the drainage of the lake might have significantly affected the climate of the lake basin. However, longer simulations and further development in some aspects of the model are needed, in order to provide a more statistically robust evaluation of the simulated lake-effects.Key words. Hydrology (anthropogenic effects) – Meteorology and atmospheric dynamics (climatology; mesoscale meteorology)

Highlights

The Fucino Lake, with an area of about 150 square kilometers, was the largest reservoir of fresh water in the Abruzzi region of central Italy until it was drained towards the end of the nineteenth century (1873)
The simulations indicate that the lake affects the temperature of the surrounding basin in all seasons and precipitation in the cold season, when cyclonic perturbations move across the region
Similar sets of organized mesoscale circulations induced by patches of surface thermal inhomogeneities have been simulated in a number of previous studies, and have been shown to possibly affect precipitation under convectively unstable conditions (e.g. Pielke, 1974; Yan and Anthes, 1988; Pielke and Avissar, 1990; Seth and Giorgi, 1996; Giorgi and Avissar, 1997)

Summary

Introduction

The Fucino Lake, with an area of about 150 square kilometers, was the largest reservoir of fresh water in the Abruzzi region of central Italy until it was drained towards the end of the nineteenth century (1873). Complex daily and seasonal circulation regimes induced by the interaction of synoptic systems, topographic slope circulations and lake breezes have been investigated by Bitan (1974) for the northwest section of the Dead Sea and by McGowan et al (1995) for the Lake Tekapo in the Southern Alps of New Zealand All these studies suggest that it is possible that some of the climatic changes over the Fucino basin suggested by the data, as well as the indirect evidence mentioned above could be at least partially explained by the drainage of the lake. The Fucino might provide a good example of a regional climate impact by a major anthropogenic modification of the land surface Based on these premises, a research program as been initiated at the University of L’Aquila aimed at investigating the long-term regional climatic effects of the drainage of the Fucino Lake via a series of regional climate simulations.

Model and experiment design

Dynamical effects

Thermo-dynamical effects

Effects on water vapor and precipitation

Sensitivity experiments

Summary and discussion