Bridging land-surface fluxes and aerosol concentrations to triggering convective rainfall

Abstract

This proposed research aims to study the lifecycle of secondary aerosols in pristine and polluted conditions in the atmospheric boundary layer (ABL) of Amazonia. The investigation spans the biological and physical conditions influencing emissions and reactions of precursors (biogenic and anthropogenic volatile organic compounds, VOCs), formation, transport of aerosols out of the ABL and their role on cloud formation and precipitation triggers. A combination of measurements of turbulent energy, trace gas and aerosol fluxes, boundary-Iayer profiles with tethered balloons and model simulations will be performed for two regions in Central Amazonia: a region with (clean air) pristine forest landscape and a region largely influenced by the plume of pollution near the city of Manaus. With innovative measurements of the vertical distribution of aerosols and cloud-condensation nuclei in the ABL and a more detailed description of dynamics and thermodynamics of the tropical stable and convective boundary layers interacting with the surface, we aim to better understand how the forest land cover influences cumulus initiation, with emphasis on how boundary-layer air is injected into the cloud layers, and how these processes are altered under the influence pollutant outflow from a megacity like Manaus. (AU)