One of the hypotheses for the Bayesian yacht accident is the presence of a downdraft. This is a rapidly descending air-flow, typically associated to a thunderstorm, that, reaching the ground, radiates with potentially very high speed. This can be very high indeed. We provide a rare example of a downdraft recording, happened at the location of the CNR-ISMAR oceanographic tower, located in the Adriatic Sea, 15 km offshore the Venice coast. As seen in the associated plots (the event happened on July 6, 2008), following a thunderstorm in a few minutes wind increased from 3 m/s to 30 m/s (108 km/h), with gusts that for 15 minutes were above the capability of the instrument (40 m/s, 144 km/h). In the same time waves increased from 30 cm to more than 3 m height, with a continuously changing direction.
Paper: Bastianini, Cavaleri, La Rocca, “An extreme meteorological event at the ISMAR oceanographic tower”, Nat. Hazards Earth Syst. Sci., 12, 281-285, 2012, available from mauro.bastianini@cnr.it, ph. 041-2407982; luigi.cavaleri@ismar.cnr.it, ph. 041-2407955
Further information:
Luigi Cavaleri
Cnr-Ismar
luigi.cavaleri@ismar.cnr.it
ph. 041/2407955
Mauro Bastianini, Cnr-Ismar,
mauro.bastianini@cnr.it
ph. 041/2407982
