The climatic evolution of the Inaouen River Basin in Morocco: Rainfall variability and its connection to the North Atlantic Oscillation

The Inaouene basin is considered among the basins most subject to rainfall variability, marked by sometimes exceptional dry periods (as low as 252.2 mm) and rainy periods (up to 1129 mm), as recorded at the Taza station, due to the variability of atmospheric factors that control atmospheric circulation, in particular the North Atlantic Oscillation.This study therefore aims to know the impact of this oscillation on the variability of rainfall by calculating the standardized precipitation index and the correlation coefficient. The study revealed that the dominance of the positive phase of the North Atlantic Oscillation since the end of the seventies had a major role in the absence of moist air masses towards Morocco, which caused the stability of climatic conditions of drought in the study area, with the presence of some extreme rainfall events, in which the evidence of the North Atlantic Oscillation is weak.