Occurrence of Ionospheric irregularities over Brazil and Africa during the 2019 Antarctic minor sudden stratospheric warming

Autor(es)

Agyei-Yeboah, Ebenezer ; Fagundes, Paulo Roberto ; Tardelli, Alexandre ; Pillat, Valdir Gil ; Vieira, Francisco ; Arcanjo, Mateus de Oliveira

• Tipo de documento: Artigo Científico
• Fonte: Advances in Space Research; v. 71, n. 1, p. 23-pg., 2022-12-17.

Resumo

The influence of sudden stratospheric warming (SSW) on the ionosphere and ionospheric irregularities has been studied extensively over the years. However, majority of these investigations have been conducted using warming events originating from the northern hemi-sphere. Only a few studies have been done on ionospheric variations due to the Antarctic SSW events and to the best of our knowledge, there have not been any studies on southern hemisphere SSW and the occurrence of ionospheric irregularities. In this study, the occur-rence of ionospheric irregularities during the 2019 minor Southern hemisphere (SH)/Antarctic SSW is investigated. The event occurs in a relatively calm solar and geomagnetic activity period which makes it possible to identify the effects of SSW on the occurrence of irreg-ularities. Three ionosondes located in different latitudinal regions in Brazil as well as a network of ground-based GPS receiver stations located in both Brazil and Africa were used for this undertaking. Complimentary data from the same ionosonde stations using the same months from 2017 and 2018 were also used. On average more Spread-F was observed in 2019 than in 2017 or 2018 at all stations. ROT observations showed more occurrence in the Brazil sectors followed by West Africa and thenEast Africa. It was observed that the occur-rence frequency decreased between 8% and 46 % from the pre-SSW phase to ascending/peak phases and from 2018 to 2019 for the peak phase.(c) 2022 COSPAR. Published by Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 19/09361-2 - Estudo da variabilidade ionosférica na região equatorial, baixas e médias latitudes em função da longitude, utilizando dados experimentais nos setores brasileiro e africano
• Beneficiário: Paulo Roberto Fagundes
• Modalidade de apoio: Auxílio à Pesquisa - Regular