Topographic control of wind‐driven circulation in the northern Adriatic

Abstract

[1] Two synoptic wind-driven situations of the circulation in the northern Adriatic were studied using the Princeton Ocean Model over the northern Adriatic Sea (NAPOM). In both situations the basin was driven by a relatively steady wind (>8 m/s) along and across the basin over three days. In the first situation (28-30 October 2008) the SSE southern jugo or scirocco wind blew along the basin, and in the second (19-21 March 2009), the ENE bora wind blew across the basin. Cyclonic turn was present in the first situation, while the cyclonic branch of a known double-gyre circulation north of the strip of wind minima was evident in the second. We show that during the jugo the model does not confirm quantitatively the simple topographic control of a wind-driven circulation, suitable for elongated basins, while qualitatively the model meets expectations, with downwind transport in shallow areas close to shorelines and upwind transport in places with greater depths. During the bora wind, however, the wind-driven circulation in the Gulf of Trieste is well explained by this topographic control (82% of the flux through the transect).Citation: Malačič, V., B. Petelin, and M. Vodopivec (2012), Topographic control of wind-driven circulation in the northern Adriatic,

Modeling the ocean and atmosphere during an extreme bora event in northern Adriatic using one-way and two-way atmosphere–ocean coupling

“…Our numerical experiments are consistent with earlier findings (Zore-Armanda and Gačić, 1987;Paklar et al, 2001;Kuzmić et al, 2007;Pullen et al, 2007;Malačič et al, 2012) in the sense that a prolonged bora generates a double cyclonic-anticyclonic gyre system in the northern Adriatic. A double gyre is related to the wind stress curl in the northern Adriatic, arising from pronounced Trieste and Senj jets to the north and south of Istria and moderate to low wind speeds in between.…”

“…Interannual simulations of the Adriatic deep-water formation indicate that it is the atmospheric forcing on synoptic spatial and temporal scales that determines the characteristics and variability of the Adriatic dense water (Mantziafou and Lascaratos, 2008). Consequently incorporation of an ocean feedback into the atmospheric model, namely, the two-way atmosphere-ocean coupling, should lead to improvements in modeled ocean and atmosphere response during synoptic events and their consequent relaxation on longer timescales.…”

Macrodebris and microplastics from beaches in Slovenia

“…The Slovenian coast is part of the Gulf of Trieste, which is a shallow (20 m depth), semi-enclosed basin with horizontal bathymetry on its southern part (Malačič et al, 2012). Four rivers contribute to fresh water input to the Gulf, two in Italy (Isonzo and Timavo), one in the proximity of Koper (Rižana), and the other further south, in Seča (Dragonja), shown in Fig.…”

Turbulence observations in the Gulf of Trieste under moderate wind forcing and different water column stratification

“…During Sirocco winds, however, the water masses at the surface are driven to the northern shore of the Adriatic Sea between Venice and Trieste, where they bifurcate in front of the GoT. The eastern part of the flow turns right and enters the GoT along its northern coastline, while the western part turns left and contributes to the coastal current flowing towards the Venice lagoon (Malačič et al, 2012).…”

“…The GoT hydrodynamics are driven by winds (Bora and Sirocco), tides, buoy- ancy effects of the Isonzo River plume and exchanges of water masses with the Adriatic Sea. The north-easterly Bora generates a cyclonic circulation in the northern Adriatic and pushes surface waters out of the GoT, inducing a compensating inflow of open-sea waters near the bottom (Malačič et al, 2012). The inflow/outflow transport is governed by topographic control of the wind-driven circulation (Csanady, 1982).…”