Severe and long-lasting meteorological drought events develop from precipitation deficits of mixed continental and oceanic origin

Abstract Drought is one of the most damaging hydroclimatic hazards, impacting environmental systems and socioeconomic sectors. Therefore, understanding the physical mechanisms that cause drought events is of critical importance. Here we investigate the influence of oceanic and continental moisture deficits on global meteorological drought events in recent decades, utilizing a Lagrangian dispersion model to track the origin of precipitation deficits leading to droughts. Additionally, meteorological drought events between 1980 and 2018 were segmented based on a three-dimension algorithm considering spatial extent, duration, and magnitude of drought events. Severe meteorological drought events exhibit mixed contribution of precipitation deficits from both continental and oceanic sources. This highlights the importance of considering both types of deficits in understanding severe meteorological droughts. Comparative analysis across time periods shows a consistent pattern in the dominant mixed contribution of precipitation deficits. There is no relevant decadal change in the mixed contributions of these deficits, which implies stability in the prevalence of oceanic and continental sources driving extreme drought events. These findings offer valuable insights into the factors shaping meteorological drought evolution.