Climatic circulation in the Gulf of Trieste (northern Adriatic)

[1] The climatic circulation of the Gulf of Trieste, which is a shallow semienclosed basin in the closed northeastern end of the northern Adriatic, is studied with a numerical model. In all seasons there is a general inflow into the Gulf of Trieste at its lower, deeper part. This inflow makes a cyclonic turn centered in the southern part during average winter conditions. This turn is enhanced during spring and closes in an elongated cyclonic gyre during average summer conditions. In spring and summer, the cyclonic gyre is coupled with an anticyclonic gyre near the closed eastern part of the gulf. A “dome”-like density profile across the gulf's axis in the inner part of the gulf above the bottom appears with this circulation during spring and summer. In climatic autumn there is a smaller anticyclonic gyre on its southern side. Near the sea surface there is an outflow during winter, which is driven by the dominant “bora” wind blowing along the gulf's axis. This outflow, however, is detached from the southern coastline to the right, and crosses the gulf diagonally, merging with the belt of freshwater outflow along the northern coastline. This is shown to be a consequence of the balance between the pressure gradient force caused by elevation piled up in the direction out of the gulf, the Coriolis force, and vertical friction between layers near the sea surface. During the stratified season the surface of the gulf is occupied by an anticyclonic gyre due to the inertial plume of the Isonzo River.

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