Vertical wind profiles at a coastal site in the central Mediterranean

An experiment was carried out during July 2009 to add new data on the vertical structure of the coastal flow at the coastal discontinuity. The coastal site is located 600m from the west coast of the Italian Region Calabria in the central Mediterranean. Here, we present the study of the vertical wind profile evolution in different weather regimes. A lidar Doppler, WLS7-0012-LEOSPHERE, was used to obtain time series of vertical profiles of wind speed and direction; the height of the Planetary Boundary Layer (PBL) was retrieved from a Vaisala CL30 ceilometer. The reflectivity of a sodar DSDPA90-24-METEK complemented the information from the lidar and characterizing the vertical thermal structures of the PBL. A surface standard meteorological station provided measurement of wind speed and direction, temperature, relative humidity, and solar radiation. An ultrasonic anemometer provided turbulent fluxes for estimating atmospheric stability. During summer, the site is characterized by both main synoptic flow and sea-land breeze system oriented along west-east. Sea breeze always develops due to the solar heating modulating the synoptic wind with its daily cycle. The sodar reflectivity before sunrise and after sunset helped in classifying the weather regimes in sea-land breeze, synoptic flow and a combination of the two. During the night, weak low level jets develop and the wind profile shows a daily variation. During synoptic flow, stability is near neutral and the wind vertical profile does not show a change in shape all day long. The most interesting surface turbulent features are detected during transition periods or during night and classified using the lidar, ceilometer and sodar signals.