Weibullova distribucija bure i juga na sjevernom Jadranu

Wind data measured at three off-shore stations in the northern part of the Adriatic Sea were considered: the Coastal oceanographic station Piran buoy (COSP), the PALOMA tower (the Gulf of Trieste) and the A. ALTA platform (Venice). Annual wind roses for all stations and additional seasonal wind roses for COSP are presented. The Weibull distribution function was applied to wind speed frequency distribution for winds from all directions and separately for bora and sirocco winds. Wind speed frequency distributions for bora winds measured at COSP and PALOMA are bimodal. One peak of this distribution of speeds belongs to nocturnal land breezes and another to bora winds. The peak separation method based on the difference in potential temperature of the atmospheric boundary layer (ABL) between two land stations (Udine and Zagreb) enabled the successful separation of the peaks of bora and land breeze winds. The frequency distribution of the wind speeds changed to the usual unimodal distribution when only those episodes were considered in which the potential temperature of ABL above Udine is higher than that above Zagreb.Obrađeni su podaci na tri morske postaje na sjevernom Jadranu: oceanografskoj plutači Obalne oceanografske postaje Piran (COSP), tornju Paloma u Tršćanskom zaljevu i na platformi A.ALTA ispred Venecije. Predstavljene su godišnje ruže vjetrova za sve tri postaje i dodatno sezonske ruže vjetrova za COSP. Weibullova distribucijska funkcija bila je primijenjena na razdiobu čestine brzine vjetra za vjetrove iz svih smjerova i posebno za buru i sirocco. Razdioba čestina brzine vjetra izmjerenog na COSP i PALOMA iz smjerova bure pokazala se kao bimodalna. Jedan vrh u toj distribuciji pripada dnevno-noćnoj cirkulaciji zraka, a drugi buri. Uspješna metoda separacije vrhova temelji se na razlici u potencijalnoj temperaturi zraka u atmosferskom graničnom sloju (AGS) iznad Udina i Zagreba. Razdioba čestina brzine vjetra postaje unimodalna kada se promatraju samo one epizode vjetra kad je potencijalna temperatura AGS iznad Udina viša od potencijalne temperature iznad Zagreba