Relationships between Dry and Wet Periods in Spring Precipitation over the Iberian Peninsula and Atmospheric Circulation

Abstract

It is well known that circulation models do not properly simulate climatic regional processes. We are therefore, learning about precipitation variations associated with circulation in order to select potential predictors that can be used in a downscaling strategy. The results obtained for spring precipitation will be discussed. A principal component analysis was performed to obtain the spatial and temporal modes of spring precipitation. Dry and wet periods were identified on the principal component time series, and the anomalous periods were compared with composite circulation maps, On the other hand, linear models between precipitation and North Hemisphere circulation indices were proposed. The Arctic Oscillation, East Atlantic/West Russian and Southern Oscillation indices were the most influential. The results suggested that the models are a good approximation to provide information about drought and rainy conditions. The study was carried out using data from different sources: observations and reanalysis projects.