Barotropic oscillations of the Mediterranean and Adriatic Seas

The periods and structures of several of the lowest barotropic free modes of oscillation of the combined Mediterranean—Adriatic system are computed. The computations take account of the two-dimensional structure of the Mediterranean—Adriatic system, the actual bottom topography, and the earth's rotation. To separate the effects of each of these factors, calculations are carried out first for uniform depth, then for variable depth but no rotation, and then for variable depth and rotation. The results show that the effect of variable bottom topography is more important than rotation. The computed periods for the lowest four modes of the Mediterranean Sea are 38.5 h. 11.4 h, 8.4 h, and 7.4 h.

In addition, the periods and structures of several of the lowest modes of the Adriatic Sea are computed without rotation on a high resolution grid. The location of the mouth of the Adriatic Sea is determined by the combined Mediterranean-Adriatic calculation. By imposing the mouth in the proper location, we found that the computed periods of the lowest modes agree with observed periods. The computed periods of the three lowest modes in the Adriatic Sea are 21.9 h, 10.7 h, and 6.7 h.