Abreu, Alessandro José deCorreia, EmiliaJesus, Rodolfo deVenkatesh, KavutarapuMacho, Eduardo PerezRoberto, MarisaFagundes, Paulo RobertoGende, Maurício Alfredo2025-02-272025-02-27https://repositorio.univap.br/handle/123456789/607The first-time statistical response of the positive and negative ionospheric storms phases using Vertical Total Electron Content (VTEC) measurements during 70 geomagnetic storms at near high- and mid-latitudes regions in the Antarctic and Argentine/Chilean sectors in the Southern hemisphere are investigated. The study covers the years between 1999 and 2018 of solar cycles 23 and 24, using the Dst ≤ −100 nT as a criterion for all 70 storms selected. Significant features of solar cycle, seasonal and local time of ionospheric storms are showed. Our results indicate that the occurrence of geomagnetic storms follows a pattern of solar activity dependence, and also indicate a predominance of positive and positive-negative phases during autumn, winter, and spring at mid-latitudes and winter at near high-latitudes. Negative and negative-positive phases occur during all seasons at near high- and mid-latitudes. In addition, positive phases occur more frequently during the daytime while the negative phases occur predominantly in nighttime. There is also a predominance of positive and positive-negative phases simultaneously at near high- and mid-latitudes in the Antarctic and Argentine/Chilean sectors. The percentages of occurrence of positive and positive-negative phases are of 50% and 19%, respectively, at mid-latitude and 60% and 22%, respectively, at near high-latitudes. Negative and negative-positive phases are below 9% at both latitudes.PDFen-USArtigos de PeriódicosElsevier10.1016/j.jastp.2023.106060Geomagnetic stormsHigh- and mid-latitudesIonosphericABREU, Alessandro José de et al. Statistical analysis on the ionospheric response over South American mid- and near high-latitudes during 70 intense geomagnetic storms occurred in the period of two decades. Journal of Atmospheric and Solar-Terrestrial Physics, v. 245, p. 1-13, 2023. Disponível em: https://linkinghub.elsevier.com/retrieve/pii/S1364682623000585.Instituto Nacional de Pesquisas EspaciaisInstituto Tecnológico de AeronáuticaPhysical Research LaboratoryUniversidade Presbiteriana MackenzieUniversidade do Vale do ParaíbaFacultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata