Thesis Defense: Deep Convection Invigoration? An analysis of convective systems in the Amazon and the roles of thermodynamics and aerosols

1. Prof. Dr. Rachel Ifanger Albrecht - IAG/USP
2. Prof. Dr. Micael Amore Cecchini - IAG/USP
3. Dr. Luiz Augusto Toledo Machado – IF/USP - on videoconference
4. Dr. Thiago Souza Biscaro – INPE - on videoconference
5. Dr. Rômulo Augusto Jucá Oliveira - Hydro Matters/França - on videoconference

Cloud-aerosol-precipitation interactions present the greatest uncertainties in global climate models, especially the microphysical effect of aerosol on cloud development. The invigoration hypothesis, which attributes the intensification of convection to the higher concentration of aerosols, remains an open research topic, with several studies confirming or denying the hypothesis using observations and/or numerical models. This work contributes to the discussion by compiling the convective systems that occurred during the GoAmazon 2014/5 experiment using radar, lightning and surface conditions estimates, including thermodynamics and aerosols. 5976 convective systems with complete life cycles within the radar coverage were identified, 47% of them lasting up to 1 h, more frequent during the wet and dry-to-wet seasons and in the late morning/early afternoon. Lightning systems were more frequent in the dry and dry-to-wet seasons. 335 (180) convective systems with convective initiation data within 25 (10) km were selected, and the classification by groups shows a greater relationship between convection parameters and thermodynamic initiation than convection and aerosols. Even by selecting the clusters of convective systems with greater aerosol representation, it was not possible to observe significant correlations between convection intensity and aerosol concentration that indicate the invigoration of deep convection.

Keywords: Cloud invigoration, GoAmazon, Radar tracking, Convective initiation