Revisiting precipitation variability, trends and drivers in the Canary Islands

摘要

The Canary Islands are characterized by their low availability of water resources and different studies have suggested a decrease of precipitation in the second half of the 20th century. Here, we have used the most complete precipitation data set available in the islands to create a dense high quality and homogeneous database, which was used to determine the spatio-temporal precipitation patterns in the archipelago and the influence of oceanic and atmospheric teleconnections. We have produced a robust regionalization of the Canary Islands precipitation, with three patterns that characterizing the south of the most montainous islands and El Hierro and La Gomera, the north of the most montainous islands and the easternmost arid islands (Lanzarote and Fuerteventura), respectively. All of them show high interannual variability, with no significant trends, except in a few cases. We highlight the strong influence of weather types and teleconections, modulated by the orography, with the highest influence recorded in the first pattern. It must be stressed that the oceanic teleconnections (in special with the tropical North Atlantic surface temperature) are more important than the North Atlantic Oscillation to explain interannual variability of precipitation.