Análise da variabilidade do campo elétrico atmosférico durante tempo bom e distúrbios geofísicos

• Autor(a) principal: Tacza Anaya, José Carlos
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do Mackenzie
• Texto Completo: http://dspace.mackenzie.br/handle/10899/25800
• topic: campo elétrico atmosférico; curva de carnegie; tempestades elétricas; circuito elétrico atmosférico global; aerossóis; explosão solar; evento de prótons solar; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOFISICA::GEOFISICA APLICADA

The monitoring of the atmospheric electric field is important to study the dynamics of the global atmospheric electric circuit and the possible coupling of the space weather with the tropospheric climate. In this thesis, we investigate the daily variation of the atmospheric electric field at different locations in South America, using a new network of electric field sensors installed in Argentina, Brazil and Peru, which was established during the course of the project. The main objective was to obtain the daily curve of the atmospheric electric field in fair weather conditions, for each station of the network, which was called standard curve, through monthly, seasonal and annual averages. The annual standard curves were compared with the universal time curve, known as the Carnegie curve, which is related to the currents flowing in the global atmospheric electric circuit. For all stations, the daily variation of the atmospheric electric field was found to have the contribution of local effects (e.g. natural radioactivity of the soil and pollution) and global effects (good correlation with the Carnegie curve). Additionally, for the station located in Argentina, we compared the monthly variation of the atmospheric electric field with the monthly global variation of the number of lightning. The results show a good similarity in the monthly variation after removing local effects (aerosols). In addition, deviations of the standard curve of the electric field were analyzed during solar flares, solar proton events and Forbush decreases, using the superposed epoch analysis. The results show no effects on the electric field variation after solar flares, but excess of ~ 10V/m are observed after intense solar proton events. The latter result indicates ionization effects above disturbed regions perturbing the global electric circuit. On the other hand, no significant effects were observed after Forbush decreases (> 4%). However, during two very intense events, > 10% and > 8%, an increase in the atmospheric electric field is observed, which indicates ionization effects in fair weather regions.