Estimation of turbulence production by nocturnal low-level jets in Sao Paulo (Brazil)

摘要

Two Doppler lidars were recently used to collect data from the planetary boundary layer (PBL) in Sao Paulo city (23°32'S, 46°38'W). The measurement campaign was carried out from December-2015 to February-2016, during the summer, which is the rainy season. Although Sao Paulo is the main city of a huge metropolitan region with more than 11 million of inhabitants and 7 millions of vehicles, according to the government agencies, the lack of PBL observational data is still a limitation for the atmospheric dispersion studies. Therefore, this work should contribute to the comprehension of PBL mechanisms and also for future atmospheric modeling studies. The data revealed that the nocturnal low-level jets (LLJs) frequently occurred along those 3 months, but its height is highly variable, from 100 m up to 650 m. It was also seen that the nocturnal LLJs can extend for several hours, right before the sunset until sunrise. This work aims to investigate the turbulence production by the nocturnal LLJs and its influence into the stable boundary layer (SBL).