Descifrando las fuentes de humedad para la precipitación en ríos atmosféricos

Abstract

Atmospheric rivers (ARs) are bands of enhanced moisture in the atmosphere which transport large volumes of water vapor, and they are mainly located in subtropical and mid-latitude oceanic areas. When they make landfall, the huge amounts of water vapor they carry are forced upwards and, as a consequence, intense or even heavy precipitation may occur, potentially leading to floods and damage. The scientific community is particularly interested in the origin of the moisture in them, with ongoing debates about whether tropical or extratropical regions contribute more significantly. To fill this gap, we use a Lagrangian moisture tracking technique validated using the WRF model with water vapor tracers (WRF-WVTs) to compute moisture sources for precipitation in selected AR cases. Preliminary results show diverse sources, including oceanic and continental regions, with notable variability across events. Unexpectedly, tropical moisture appears less significant than previously thought, although its role remains crucial in the early stages of AR formation.