Fontes Neto, Pedro AlvesMuella, Marcio Tadeu de Assis HonoratoResende, Laysa Cristina AraújoFagundes, Paulo Roberto2025-02-072025-02-062025-02-07https://repositorio.univap.br/handle/123456789/554.2Sporadic E-layers (Es) are thin and denser layers with high ionization observed at about 100–140 km altitude in the E region. Their formation is mainly associated with the tidal components of the diurnal and semidiurnal winds with the convergence of ions driven by the wind shear mechanism. This present work shows evidence of the relationship between the occurrence of Es layers and the solar activity at two observatories located in the Brazilian sector, the near-equatorial site of Palmas (PAL, 10.17 S; 48.33 W; dip lat. 7.31 ) and the low latitude station of Sa ̃o Jose ́ dos Campos (SJC, 23.18 S; 45.89 W; dip lat. 19.35 ). The analysis was performed from Decem- ber/2008 to November/2009 (a period of low solar activity) and from December/2013 to November/2014 (a period of high solar activity) using data collected from two digital ionosondes. Our results show an anti-correlation of the Es layer occurrence concerning the solar activity over both stations studied here. A more clearly observed anti-correlation at the SJC station can be attributed to a greater tidal amplitude at low latitudes. Other relevant aspects of the observations associated with the formation of the Es layers are highlighted and discussed.PDFen-USArtigos de PeriódicosPedro Alves Fontes NetoMarcio Tadeu de Assis Honorato Muella10.1016/j.asr.2023.09.040Sporadic (Es) layerSolar activityIonosphereFontes Neto, Pedro Alves et al. Evidence of anti-correlation between sporadic (Es) layers occurrence and solar activity observed at low latitudes over the Brazilian sector. Advances in Space Research, v. 73, n. 7, p. 3563–3577, 2024. Disponível em: https://linkinghub.elsevier.com/retrieve/pii/S0273117723007627.Universidade do Vale do ParaíbaInstituto Federal do MaranhãoState Key Laboratory of Space WeatherInstituto Nacional de Pesquisas Espaciais