Resumo

ABOITIZ, A; TEJEDOR, B; MUNOZ, JJ  e  ABARCA, JM. Relation between daily variations in sea level and meteorological forcing in Sancti Petri Channel (SW Spain). Cienc. mar [online]. 2008, vol.34, n.4, pp.491-501. ISSN 0185-3880.

Sea level series were recorded from October 2006 to January 2007 at two different sites in a shallow-water estuary of SW Spain. Results showed a very significant temporal variability in daily sea level. Moreover, 85% of the variance was explained by atmospheric pressure variability, obtaining a relation between sea level and atmospheric pressure of around -2 cm hPa^-1. A more detailed study showed the existence of two different types of oscillations in daily sea level: the first, with periods of 10 days, was related to the inverted barometer (IB) effect associated with synoptic-scale atmospheric pressure oscillations (IB factor of around 1.4 ± 0.1 cm hPa^-1), and the second, with periods of more than 10 days, was related to pressure changes in the planetary-scale atmospheric waves. Even though the high barometric behaviour of the 10-day period was partially related to the local winds, the shallowness of the study area invalidated the assumption of a static IB effect (-1 cm hPa^-1). Rather, it was the dynamic IB effect that explained the displacement of the IB factor relative to the static assumption.

Palavras-chave : inverted barometer effect; long-period sea level oscillations; shallow waters.