A numerical investigation of the sea breeze and slope flows around Rome

A trhee-dimensional non-hydrostatic prognostic mesoscale model is used to simulate the circulation around Rome, Italy on a cloudless summer day with weak synoptic winds, with the aim of characterisingthe local circulation on such days. The simulation shows that the sea breeze and the slope flows play roles of comparable importance. At night the circulation is dominated by katabatic flow. During the late morning/early afternoon there is a sea breeze with a front curving pincer-like around Rome, and well-developed anabatic flows on all slopes. In the late afternoon, sea breeze and slope flows coalesce into a single circulation reaching hundreds of kilometers inland, with an offshore return flow aloft. Comparison with observations is favorable, particularly during the day.