Bonus HAPpy Hour Seminar: Impacts of Northerly Low-level Jets on Mesoscale Convective Systems East of the Andes

Join us for a special bonus HAPpy Hour outside of our regularly-scheduled programming!

Abstract: The low-level jet (LLJ), located on the eastern Andes, is responsible for the significant transport of moisture and control of the spatiotemporal distribution of precipitation in South America. The LLJ is present year-round, but it has a distinct role in the formation of mesoscale convective systems (MCS). This study investigates the impacts of LLJs on MCSs, including their intensity, duration, diurnal cycles, and precipitation. The analysis used the European Centre for Medium Range Weather Forecasts Reanalysis (ERA5) for the LLJ identification. MCS tracking is based on the Tracking and Object-based Analysis of Clouds (tobac) algorithm, which uses the Integrated Multi-satellite Retrievals for GPM (IMERG), infrared brightness temperature, and km-scale Weather Research and Forecasting (WRF) data to identify and track MCS precipitation. Discrepancies exist between IMERG and WRF simulated precipitation and diurnal cycle. Strong LLJs are linked to extended MCS duration, larger size, and greater maximum precipitation at the jet exit region in the Amazon and La Plata basins.