Seminar in Atmospheric Sciences

September 18, 3:30pm - 5:00pm
Mānoa Campus, MSB 100 (Marine Sciences Building) Add to Calendar

Environmental controls on isolated convection in the Amazon: an observational and numerical modeling study Dr. Leandro Alex Moreira Viscardi Postdoctoral Researcher Atmospheric Sciences UH Manoa. ABSTRACT The Amazon rainforest is a vital component of the global climate system, influencing the hydrological cycle and tropical circulation. However, understanding and modeling the evolution of convection in this region remains a scientific challenge. In this study, we combined recent observations and high-resolution simulations to evaluate the relative importance of different environmental controls on locally-driven convection in the Amazon. Observationally, we assessed the environmental conditions associated with shallow, congestus, and isolated deep convection days during the wet season (December to April), employing data from the GoAmazon (2014-2015) experiment. Composites of deep days show moister than average conditions below 3 km early in the morning. Water vapor convergence increases significantly in the afternoon when the shallow-to-deep convective transition occurs around 16-17 LST. Moreover, afternoon precipitation increases with large-scale vertical velocity, humidity at different levels and periods of the day, and low-level wind shear. Numerical simulations indicated that daytime convection shows a noticeable sensitivity to pre-convective low-level humidity and a weaker response to free troposphere humidity. Vertical wind shear primarily influences ice content, but its role is smaller than that of humidity in the shallow-to-deep convective transition.


Event Sponsor
Atmospheric Sciences, Mānoa Campus

More Information
Christina Karamperidou, 808-956-2565, ckaramp@HAWAII.EDU, http://www.soest.hawaii.edu/atmo, Viscardi seminar (PDF)

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