Climatological analysis of the annual and interannual precipitation in the río Grande de San Ramón basin, Costa Rica

This project investigates three sectors located in the central basin of the río Grande San Ramón in Costa Rica. In spite of their proximity to each other, these stations show considerable variation, both temporal and spatial in intra- and interannual precipitation. This variation is attributed to regional atmospheric circulation patterns in the equatorial Pacific, producing strong precipitation during some years, and declines in others. There is a greater probability of lower annual precipitation during El Niño years and higher probabilities of large totals during La Niña years. The warm phase, El Niño, of the El Niño-Southern Oscillation phenomenon (ENSO) is more pronounced in Naranjo, which is located on the lower slope of the Central Volcanic Mountain range. The influence of regional/hemispherical cannot be regarded homogeneous in mountainous areas where local conditions may prevail.