Dana 30.05.2017. (utorak) u 15:15 h održat će se na Geofizičkom odsjeku PMF-a
(predavaona P1) sljedeće izlaganje:
(Department of Mathematics, University of Ioannina, Greece)
Up- and down-slope winds at Zagreb
Pozivaju se studenti, apsolventi i svi zainteresirani da prisustvuju predavanju, koje će se održati u predavaoni P1 Geofizičkog odsjeka PMF-a, Horvatovac 95, Zagreb.
This presentation investigates the frequency of up- and down-slope winds at Zagreb. A few past research studies have focused on the winds in the area of Zagreb. Accordingly, there is a gap in the scholarly literature regarding the occurrence of these thermal circulations established at slopes of Medvednica Mountain.
This report addresses the following topics: how frequent are the up-and-down slope winds in Zagreb, and which are the most frequent wind directions for Zagreb-Horvatovac measuring site. The hourly mean wind data analysed correspond to the period from 1/1/2004 to 30/10/2014. They were measured by automatic meteorological station META2000 (AMES, Brezovica, Slovenia). Wind sensors for horizontal air flow were placed at 4.3 meters above the Geophysics department building roof terrace (17.3 m above the ground).
In order to select up- and down-slope winds, several conditions were imposed. To eliminate strong (sinoptically forced) flows, only the winds with the speeds less or equal the average speed plus standard deviation were taken. During the daytime and nighttime, only hours from 11 to 17 LST and from 22 to 04 LST, respectivly, were analyzed. Additionally, up-slope winds were considered as daytime winds with directions between 123 and 191 deg, while down-slope winds corresponded to the nighttime directions between 303 and 11(317deg) deg. It is shown that 26.7 % of daytime and 37.8 % of nighttime winds corresponded to up- and down-slope winds,