Rawinsonde-Based Analysis of the Urban Boundary Layer in the Metropolitan Region of Sao Paulo, Brazil

Autor(es)

Sanchez, Maciel Pinero ^[1] ; de Oliveira, Amauri Pereira ^[1] ; de Varona, Ramon Perez ^[2] ; Tito, Janet Valdes ^[1] ; Codato, Georgia ^[1] ; Dutra Ribeiro, Flavia Noronha ^[3] ; Marques Filho, Edson Pereira ^[4] ; da Silveira, Lucas Cardoso ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Astron Geophys & Atmospher Sci, Dept Atmospher Sci, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Phys, Dept Expt Phys, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo - Brazil

^[4] Univ Fed Bahia, Interdisciplinary Ctr Energy & Environm, Salvador, BA - Brazil

• Tipo de documento: Artigo Científico
• Fonte: EARTH AND SPACE SCIENCE; v. 7, n. 2 FEB 2020.
• Citações Web of Science: 0

Resumo

The main features of the urban boundary layer in the metropolitan region of Sao Paulo are estimated based on rawinsondes carried out (a) every 3 hr in two 10-day field campaigns of the MCITY BRAZIL Project during the summer and winter of 2013 and (b) regularly once per day and continuously for 4 years from 2009 to 2013. On average, the boundary layer height showed a daytime maximum of 1476 +/- 149 m in summer and 1122 +/- 168 m in winter campaigns. The differences are related to seasonal variations in the (a) buoyancy flux at the surface, which was 30% larger in summer (4.7 +/- 0.6 MJ m(-2) day(-1)), and the (b) static stability of the free atmosphere, which was 15% smaller in summer (3.3 +/- 0.1 K km(-1)). The average nighttime boundary layer height, estimated from equilibrium empirical expression, indicated maximum of 126 +/- 13 m in summer and 122 +/- 10 m in winter campaigns. The presence of a low-level jet was identified in 80% of the field campaign nights, with intensity varying from 2.7 to 14 m s(-1) and height ranging from 95 to 962 m. The nighttime residual-mixing layer is well estimated using the air temperature gradient method and is a good indication of the maximum vertical evolution of the previous daytime boundary layer. The monthly average maximum boundary layer height varied from a minimum of 1,061 +/- 77 m in September to maximum of 1,632 +/- 96 m in May. (AU)

• Processo FAPESP: 11/50178-5 - Micrometeorologia urbana tropical aplicada às mudanças climáticas das regiões metropolitanas de São Paulo e Rio de Janeiro
• Beneficiário: Amauri Pereira de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular