Interrelationships of Similar Magnetic Effects at Low and High Latitudes During High-Intensity Long-Duration Auroral Activity Events: Case Studies

Autor(es)

Mendes, Odim ; Adhikari, Binod ; Domingues, Margarete Oliveira ; Echer, Ezequiel ; Takeshi, Rodrigo Seo

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Physics; v. 52, n. 5, p. 20-pg., 2022-10-01.

Resumo

As known, geomagnetic storms and substorms are caused by intensified solar wind-magnetosphere energy coupling processes. Recorded on the ground at high latitudes as geomagnetic disturbances, High-Intensity Long-Duration Continuous Auroral Electroject Activities (HILDCAAs) occur related to the same magnetospheric processes. Improving the magnetic effect understanding during HILDCAAs, this work investigates the characteristics of similar geomagnetic effects at the high and low latitudes from those kinds of events. A strategy is to deal with case studies; we selected HILDCAAs involving different interplanetary scenarios. One primary situation is HILDCAA not preceded by a geomagnetic storm; another situation is HILDCAA preceded by a Corotating Interacting Region (CIR) storm. Finally, there is HILDCAA preceded by an Interplanetary Coronal Mass Ejection (ICME) storm. A geomagnetically quiet case has also been examined as part of the cases to a complete comparison. The methodology involves three numerical approaches. A signal-normalised equivalent-energy variable for the auroral index AE and low-latitude asymmetric ring current geomagnetic index asy-H aid in highlighting similarities in the signal regimes. Together a dynamical time distortion analysis identifies the lags between the magnetic effect regimes. Wavelet multiscale analyses allow spectral characterisation in those effects during the coupling processes. Undoubtedly, the general criteria currently maintain applicable to categorise the HILDCAA events. Nevertheless, using well-defined quantitative approaches, the results point out non-linear peculiarities superposed on the general expected pattern. At the same time, the results show that phenomena recognised under a unique designation present rich details, differing among them by the influence of a complicated coupling process linked to the alternate triggerings of the frontal magnetic reconnection and the viscous interaction on the magnetopause flanks. (AU)

• Processo FAPESP: 15/25624-2 - Desenvolvimento de modelagem multiescala para instabilidades locais não-lineares em Astrofísica e Geofísica Espacial
• Beneficiário: Margarete Oliveira Domingues
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 20/13015-0 - Plano Anual de Aplicação da Parcela da Reserva Técnica Para Custos de Infraestrutura Institucional para Pesquisa: Atualização e otimização das facilidades de testes de antenas, conserto de equipamentos multiusuários e aquisição de novos equipamentos
• Beneficiário: Carlos Alexandre Wuensche de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Reserva Técnica para Infraestrutura Institucional de Pesquisa
• Processo FAPESP: 18/21657-1 - Estudo da variabilidade da atividade auroral em rádio da magnetosfera de Júpiter
• Beneficiário: Ezequiel Echer
• Modalidade de apoio: Auxílio à Pesquisa - Regular