Surface energy balance in a suburban area of the megacity of São Paulo - Seasonal variation and closure

• Published in: Urban climate 2024-07, Vol.56, p.102008, Article 102008
• Main Authors: Ferreira, Mauricio Jonas, de Oliveira, Amauri Pereira, da Silveira, Lucas Cardoso, Codato, Georgia, Fornaro, Adalgiza, Borbon, Agnès
• Format: Article
• Language: English
• Subjects: Energy balance closure (EBC); Energy flux; Subtropical region; Surface energy balance (SEB); Urban climate
• ISSN: 2212-0955; 2212-0955
• DOI: 10.1016/j.uclim.2024.102008

The study addressed the seasonal variation and closure of the Surface Energy Balance (SEB) in a suburban area of the Megacity of São Paulo. This area consists of a combination of buildings and vegetation classified into local climate zone typologies 5 (38.5%), 6 (26.7%), and 8 (11.2%), along with areas exclusively with vegetation representing 12.1%. The investigation is based on high-quality measurements taken during February (rainy summer) and August (dry winter) between 2013 and 2015. The greatest seasonal variation was observed in latent heat flux, reaching 64.7% for daily values and 63.9% for daytime values. The smallest was observed by sensible heat flux, reaching 20.3% and 24.1%, respectively. This suggests that seasonal variation in temperature and humidity plays a crucial role in energy distribution, generating uncertainties in the closure of the energy balance. The largest difference between energy input and output was seen in August, reaching 25% for daily values and 45% for daytime values. The gap saw in closure is consistently larger in winter. The results contributed to improving understanding of energy exchanges in the surface-canopy-atmosphere system, being essential in the development of more correct meteorological and hydrological models. •High-quality data were used to investigate the surface energy balance (SEB) closure in the megacity of São Paulo.•These data were employed to characterize the seasonal variation of the main SEB components.•Latent heat flux (QLE) exhibits greater seasonal vaiation compared to sensible heat flux (QH), net radiation (Q*), and soil heat flux (ΔQS).•The SEB closure gap reaches 25% for daily values and 45% for daytime values.•The closure difference in winter is larger than in summer.