The port of Málaga is routinely affected by short period sea level oscillations whose amplitudes, typically of few cm, can sporadically outweigh the tidal variations. High frequency oscillations in the innermost
basins may cause problems of stability of the moored crafts. This motivated the characterization of the
resonant behavior of the port and its response to external forcing, which has been carried out by
experimental and numerical approaches. The Helmholtz mode of the harbor has been found at 16.5-
min period, in both observed data and numerical experiments. A second mode of period around
6–7 min, beyond the temporal resolution of the tide gauge, has been detected only in the numerical
results. The typical scenario during the occurrence of harbor oscillations is a low atmospheric pressure
(75% of the cases) with noticeable content of high frequency pressure disturbances, a situation that is
quite commonly observed during the transit of atmospheric fronts across the Iberian Peninsula. Winds
appear to be of secondary influence, even when the oscillations are preferably observed under
westerlies. Although results are not conclusive, resonance mechanisms (Proudman and Greenspan
resonance) for transferring energy from the atmosphere to the ocean are proposed as the physical
process generating the harbor oscillations.
