Observational Investiontion of the Low-Level Jets in the Metropolitan Region of Sao Paulo, Brazil

Autor(es)

Sanchez, Maciel Pinero ; de Oliveira, Amauri Pereira ; Varona, Ramon Perez ; Tito, Janet Valdes ; Codato, Georgia ; Ynoue, Rita Yuri ; Dutra Ribeiro, Flavia Noronha ; Marques Filho, Edson Pereira ; da Silveira, Lucas Cardoso

• Tipo de documento: Artigo Científico
• Fonte: EARTH AND SPACE SCIENCE; v. 9, n. 9, p. 24-pg., 2022-09-01.

Resumo

The main features of low-level jet (LLJ) in the metropolitan region of sao Paulo (MRSP), Brazil, are assessed using rawinsondes carried out: (a) every 3-hr during 10-consecutive days in summer and winter field campaigns of the MCITY BRAZIL Project in 2013, (b) at 0900 and 2100 local time, from September 2009 to August 2013. These observations indicate that the LLJ is a typical feature of the MRSP, observed in 85% of the 20 days of the field-campaigns and 77.6% of the 1,446 days of regular rawinsonde period. The fine temporal and spatial resolution soundings indicate that most of the LLJs occur during nighttime and early in the morning, with mean intensity of 8.5 +/- 0.3 m s(-1), height of 539 +/- 26 m, and mostly (52.5%) from east and north. The coarse resolution soundings indicate the LLJ display a seasonal variation with maximum intensity in October (8.6 +/- 0.3 m s(-1)) and a minimum in February (7.1 +/- 0.2 m s(-1)), a maximum height in March (703 +/- 151 m) and a minimum in June (577 +/- 151 m). During MCITY campaigns about 76.4% of LLJ events show inertial oscillation and 35.3% of them are combined with sea breeze. Only 17.6% of LLJ events are associated with cold fronts and post-frontal high pressure system. The urban heat island intensity, surface inversion layer strength, particulate matter 2.5 and carbon monoxide concentrations are negatively correlated with the LLJ intensity, suggesting the jet-induced turbulent mixing may contribute to reduce them. (AU)

• Processo FAPESP: 20/07141-2 - Emissões biogênicas, química e impactos na Região Metropolitana de São Paulo: BIOMASP+
• Beneficiário: Adalgiza Fornaro
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• 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