Recommended citation: Pérez-Alarcón, A, Trigo, R.M., Nieto, R., Gimeno, L. (2024). Lagrangian analysis of moisture sources for precipitation of tropical cyclones in the North Atlantic basin . V Congress in Tropical Meteorology. Convención TROPICO 2024. Havana, Cuba. 21-25 October 2024.

Abstact

Tropical cyclones (TCs) are among the most dangerous and destructive natural hazards in tropical and subtropical latitudes. Understanding the underlying mechanisms of TC genesis and intensification processes and associated extreme weather helps to improve our skills in seasonal TC forecasting. This study examines the origin of the precipitation produced by TCs along their trajectories in the North Atlantic (NATL) basin from 1980 to 2018 by applying a Lagrangian moisture sources analysis. Our results confirm the role of the ocean surface as the principal source of moisture and energy for TC activity. However, we found differences in the moisture contribution from the oceanic sources depending on the TC trajectory. While the Caribbean Sea, Gulf of Mexico and tropical NATL are the main moisture sources for straight-moving TCs, the western and subtropical eastern NATL achieve the highest contribution for recurving landfalling and recurving ocean TCs, respectively. These results show that TCs gain more moisture from local than remote sources, supported by the short mean water vapour residence time (~2.8 days). Furthermore, our findings reveal differences in the moisture source pattern before and after the extratropical transition (ET). The moisture contribution occurred predominantly from the south and southwest sectors within ∼2,000 km of the TC centre before ET and from the southwest and west sectors after ET. Overall, this study has important implications for understanding changes in TC activity under global warming.