Anatomy of Convective Clouds over the Amazon (ACCA)

• Grant number: 20/13273-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2020
• End date: October 31, 2021
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Meteorology
• Principal Investigator: Paulo Eduardo Artaxo Netto
• Grantee: Micael Amore Cecchini
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/17047-0 - Aerosol and clouds life cycles in Amazonia: biogenic emissions, biomass burning and impacts on ecosystem, AP.PFPMCG.TEM

Abstract

Convective clouds play a key role in the water, carbon, and energy budgets over the Amazon. Pollution emitted by biomass burning or anthropogenic activities significantly disrupts the cloud characteristics by increasing the number of droplets while reducing their mean size. We propose a new approach to investigate whether such changes lead to cloud invigoration or inhibition, respectively increasing or decreasing their horizontal area, depth, and likelihood of transitioning from shallow to deep convection. The originality relies on integrating microphysical, dynamic, and chemical processes. The project is timely since recent studies have linked deep convective clouds to new aerosol particle formation in the upper troposphere that later nucleate clouds in the boundary layer. We will focus on processes occurring at the cloud core and at its margins. Our combined hypothesis is that smaller droplets produce both an intensification of the updrafts at the core, leading to invigoration, and an intensification of the downdrafts at the margins, promoting inhibition. We propose to objectively analyze the diurnal variability of the convective cloud anatomy over the Amazon using high-resolution (meter-scale) numerical experiments and recent remote sensing and aircraft-based measurements. The Post-Doc has actively participated in several measurement campaigns in the region, as shown in his CV. ACCA outcome will enable us to understand how cloud diurnal cycling depends on instability, wind shear and humidity to identify regimes of aerosol invigoration or inhibition of clouds and the effect on the shallow-to-deep transition. This is crucial to represent the local seasonality since aerosol concentrations span more than 2 orders of magnitude between the wet and dry seasons. This new understanding aims to reduce the uncertainty around clouds in the Amazon region. (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PARDO, LIANET HERNANDEZ; MACHADO, LUIZ A. T.; MORRISON, HUGH; CECCHINI, MICAEL A.; ANDREAE, MEINRAT O.; POEHLKER, CHRISTOPHER; POESCHL, ULRICH; ROSENFELD, DANIEL; VENDRASCO, EDER P.; VOIGT, CHRISTIANE; et al. bserved and Simulated Variability of Droplet Spectral Dispersion in Convective Clouds Over the Amazo. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, v. 126, n. 20, OCT 27 2021. (16/24562-6, 20/13273-9, 19/06988-4)

CECCHINI, MICAEL A.; HEYMSFIELD, ANDREW J.; HONEYAGER, RYAN; FIELD, PAUL; MACHADO, LUIZ A. T.; DA SILVA DIAS, MARIA A. F.. Revisiting the Hail Radar Reflectivity-Kinetic Energy Flux Relation by Combining T-Matrix and Discrete Dipole Approximation Calculations to Size Distribution Observations. JOURNAL OF THE ATMOSPHERIC SCIENCES, v. 79, n. 7, p. 14-pg., 2022-07-01. (20/13273-9, 17/17047-0, 15/14497-0, 18/09082-3, 17/04654-6)

CORREIA, ALEXANDRE L.; MENDONCA, MARINA M.; NOBREGA, THIAGO F.; PUGLIESI, ANDRE C.; CECCHINI, MICAEL A.. Multi-Year Study of GOES-13 Droplet Effective Radius Retrievals for Warm Clouds over South America and Southeast Pacifi. TMOSPHER, v. 13, n. 1, JAN 2022. (20/13273-9, 10/15959-3)

CECCHINI, MICAEL AMORE; DE BRUINE, MARCO; DE ARELLANO, JORDI VILA-GUERAU; ARTAXO, PAULO. Quantifying vertical wind shear effects in shallow cumulus clouds over Amazonia. Atmospheric Chemistry and Physics, v. 22, n. 17, p. 22-pg., 2022-09-14. (17/17047-0, 20/13273-9)