Quantifying the aerosol effect on droplet size distribution at cloud top

Author(s)

Pardo, Lianet Hernandez ^[1] ; Toledo Machado, Luiz Augusto ^[1] ; Cecchini, Micael Amore ^{[1, 2]} ; Gacita, Madeleine Sanchez ^{[1, 3]}

Affiliation

^[1] Inst Nacl Pesquisas Espaciais, Ctr Previsao Tempo & Estudos Climat, Cachoeira Paulista - Brazil

^[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Ciencias Atmosfer, Sao Paulo - Brazil

^[3] Inst Nacl Pesquisas Espaciais, Ctr Ciencia Sistema Terr, Sao Jose Dos Campos - Brazil

• Document type: Journal article
• Source: Atmospheric Chemistry and Physics; v. 19, n. 11, p. 7839-7857, JUN 12 2019.
• Web of Science Citations: 0

Abstract

This work uses the number concentration-effective diameter phase-space to test cloud sensitivity to variations in the aerosol population characteristics, such as the aerosol size distribution, number concentration and hygroscopicity. It is based on the information from the top of a cloud simulated by a bin-microphysics single-column model, for initial conditions typical of the Amazon, using different assumptions regarding the entrainment and the aerosol size distribution. It is shown that the cloud-top evolution can be very sensitive to aerosol properties, but the relative importance of each parameter is variable. The sensitivity to each aerosol characteristic varies as a function of the parameter tested and is conditioned by the base values of the other parameters, showing a specific dependence for each configuration of the model. When both the entrainment and the bin treatment of the aerosol are allowed, the largest influence on the droplet size distribution sensitivity was obtained for the median radius of the aerosols and not for the total number concentration of aerosols. Our results reinforce that the cloud condensation nuclei activity can not be predicted solely on the basis of the w/N a supersaturation-based regimes. (AU)

• FAPESP's process: 17/04654-6 - Studying macro and microphysical phase spaces in thunderstorm clouds: insights for nowcasting techniques
• Grantee: Micael Amore Cecchini
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 16/24562-6 - Combining observations and numerical modeling to improve the description of thunderstorm microphysical processes
• Grantee: Lianet Hernández Pardo
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/14497-0 - Nowcasting of intense thunderstorms and understanding of the physical processes inside clouds: the SOS-CHUVA (Severe Weather Observation System)
• Grantee: Luiz Augusto Toledo Machado
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants