Coastal upwelling in the Baltic - a presentation of satellite and in situ measurements of sea surface temperatures indicating coastal upwelling Part l and ll

Typ: Rapport
Serie: RHO 37
Författare: Lars Gidhagen


Satellite data (AVHRR) and in situ data of sea surface temperatures have been used to describe wind-induced upwelling along the Swedish coast of the Baltic.

The satellite data, transformed to isotherm charts  points out three sections of the coast where the upwelling is especially intense. The cold upwelled water, normally found within 10 - 20 kilometres from the coast, sometimes spreads out in finger-like filaments. There are indications of propagation of upwelling fronts and centers, which may be associated with coastal-trapped waves. .

Ten years of insitu measurements of sea surface temperature have been used for a statistical compilation of upwelling events. The statistics reveal that upwelling is a common feature along certain sections of the coast, occuring for about one fourth to one third of the time. Some information of time- scales and temperature anomalies associated with the upwelling events are also given. A wind analysis shows a correlation between upwelling and winds parallell to the shoreline, in accordance with the Ekman theory of upwelling generation.