A general view of the hydrographic and dynamical patterns of the Rías Baixas adjacent sea area

The hydrography and dynamics of the Rias Baixas adjacent shelf region is reviewed in this paper with the aim to serve as a general 'state-of-the-art' reference and to help introduce several topic-related articles in this special volume. This introductory article is structured as follows: first, a brief description of the general topographic and bathymetric characteristics and the tidal regime is given; afterwards, the water masses existing in the region, as well as their circulation patterns are reviewed with much more detail. In this context, we focus on the characteristics of the water masses involved in the main oceanographic process that occurs in this area (the upwelling of Eastern North Atlantic Central Water and the Mediterranean Water). To better reflect this purpose, bibliographic data are used, but also 46 CTD new data samplings all around the year from a station off Ría of Vigo are gathered. In this section, we extensively discuss the present dilemmas about the Iberian Poleward Current system, confronting some classical and more recent views about its seasonality. After that, concise but novel and relevant information on very recent observations of short period internal waves in the near shelf area is presented, pointing out about their importance on the thermohaline structure of the water column. This introductory paper is closed with some thoughts on what we consider either interesting or necessary work that should be performed in this area during the next coming years.