VARIATIONS IN SEASONAL RAINFALL IN SOUTHERN EUROPE DURING THE PRESENTCENTURY - RELATIONSHIPS WITH THE NORTH-ATLANTIC OSCILLATION AND THE EL-NINO SOUTHERN OSCILLATION

Analysis of data from seventeen rainfall stations in the Iberian Penin sula, Balearic Islands and Northern Africa has revealed significant El Nino-Southern Oscillation (ENSO) signals in Europe. Both North Atlant ic Oscillation (NAO) and Southern Oscillation (SO) exert an influence on Iberian climate, but at different temporal and spatial scales. Thou gh most of the peninsula is under NAO influence in winter, some statio ns in the eastern region show no connection with this phenomenon. The same is found for ENSO, with a positively correlated region appearing in the eastern part of Spain, while the rest of the peninsula remains insensitive. The correlation between ENSO and Iberian rainfall has inc reased towards the end of the present century, with strong positive si gnals spanning over half of the area studied. The percentage of spring time variability due to ENSO has similarly increased, reaching up to 5 0% in certain areas. We also show how there are outstanding climatic s ensors of these phenomena such as Lake Gallocanta, which manifests a p ositive response to ENSO while appears insensitive to NAO. Common long -term patterns are observed between SOI and an inferred lake level ser ies, suggesting a constant influence of the low-frequency component of ENSO throughout the period considered. Lake drying phases every 14 ye ars reflect the impact of this signal, approximately every four ENSO e vents.