Influences of atmospheric variability on freshwater input in Galician Rías in winter

Abstract

The influence of the preferred modes of variation of the atmosphere in the North Hemisphere on the precipitation variability was evaluated in Galicia (NW Iberian Peninsula). The special location of Galicia requires consideration of the influence of several indices that characterize the atmosphere in order to explain the variability of precipitation and consequently the flow regime of its rivers. We calculate the correlation between the precipitation data obtained from 47 rain-gauge stations covering Galicia from 1977 to 1998 and the five principal teleconnection patterns on the Atlantic area of North Hemisphere (NAO, EA, EA/WR, SCA, and POL). The results obtained show significant correlations between winter precipitation and these patterns, and clear spatial distribution of their influence within Galicia. This result could be related directly to the freshwater discharge in the different Galician Rias each winter, which would improve the hydrodynamical description of these estuaries.