Rawinsonde‐Based Analysis of the Urban Boundary Layer in the Metropolitan Region of São Paulo, Brazil


Primeiro Autor: 
Maciel Piñero Sánchez
Ano de Publicação: 
Nome da Revista/Jornal: 
Earth and Space Science
Tipo de publicação: 
Artigo publicado em Revista
Publicação Internacional
TítuloRawinsonde‐Based Analysis of the Urban Boundary Layer in the Metropolitan Region of São Paulo, Brazil
Tipo da publicaçãoJournal Article
Ano de Publicação2020
AutoresPiñero Sánchez M, Oliveira AP, Varona RP, Tito JV, Codato G, Ribeiro FND, Marques Filho EP, da Silveira LC
JournalEarth and Space Science
Paginação1 a 40
Data de Publicação01/2020

he main features of the urban boundary layer in the metropolitan region of São 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.

Short TitleEarth and Space Science