Do We Obtain Different Estimates of Precipitation Recycling Using Convection-Permitting (CP) Vs. Non-CP Models?

Convection-permitting models (CPM) simulations at the continental scale have recently emerged, opening new avenues in the study of continental precipitation. In particular, the South America Affinity Group (SAAG) developed a 22-year CPM simulation for the entire South American continent at 4-km resolution that shows a realistic representation of precipitation intensity features when compared with rain gauge data. We hypothesize that the estimation of moisture source regions and their contribution can significantly change when an explicit representation of mesoscale convection is integrated in simulations. To test this hypothesis, the SAAG’s CPM simulation and a non-CPM simulation are compared in terms of ratios of moisture contribution from source regions and vertical fluxes between layers obtained using the 2L-DRM moisture tracking model. For that purpose, a study area in southeastern South America and five extreme precipitation events were selected. The study area is characterized by the presence of strong convective storms. Preliminary results from the CPM simulations shows that up to 60 % of total precipitation in these events originates from evaporation in the La Plata basin and that the recycling ratio is close to 0.4. We will compare these estimates with non-CPM simulations. The final results from the CPM and non-CPM cases aim to provide a better understanding of the interplay between mesoscale convection and the transport of moisture for precipitation.