Análise de áreas de coerência entre estações conjugadas afetadas pela Anomalia Magnética do Atlântico Sul
DOI:
https://doi.org/10.22456/1807-9806.140792Palavras-chave:
Anomalia Magnética do Atlântico Sul, estações conjugadas, coeficientes de correlação, áreas de coerência, coerência wavelet, geofísica espacialResumo
A Anomalia Magnética do Atlântico Sul (AMAS) é uma região do Oceano Atlântico Sul onde o campo magnético da Terra é significativamente mais fraco do que em outras partes do mundo. Esta anomalia tem despertado o interesse de cientistas e pesquisadores que estudam o campo magnético da Terra. A AMAS pode afetar sistemas de navegação e operações de satélites, sendo uma importante área de estudo para a compreensão da dinâmica do campo magnético terrestre. Este artigo pesquisa as características do sinal de estações conjugadas influenciadas pela AMAS em uma tempestade geomagnética moderada através da análise de registros de estações geomagneticamente conjugadas interligando em ambos os hemisférios. Este estudo utiliza a componente magnética horizontal medidos no mesmo intervalo de tempo e em duas longitudes típicas: a região América-SAMA e a região Ásia-Pacífico. Este procedimento permite fazer uma análise comparativa entre regiões. Nosso procedimento utiliza os dados registrados simultaneamente em quatro pares de estações conjugadas para caracterizar o domínio de coerência da variabilidade magnética em torno das estações conjugadas. Aqui apresentamos e discutimos os primeiros mapas da região SAMA, que corresponde à área de coerência em baixas latitudes. Na verdade, este conceito de área de coerência refere-se às bordas (área geométrica próxima ao solo) em torno do ponto conjugado, onde os fenômenos geofísicos geralmente exibem comportamento flutuante semelhante. Para o cálculo dessas áreas foi utilizada a técnica dos coeficientes de correlação, utilizando a componente H do campo geomagnético. Nossos principais resultados indicam que as áreas da região Ásia-Pacífico são semelhantes em tamanho e formato, o que caracteriza padrões típicos. Na região América-SAMA, as áreas de coerência das estações conjugadas não são semelhantes em formato e tamanho. Estas diferenças entre as áreas de coerência podem ser devidas às características únicas da região, ou seja, apresenta uma condutividade ionosférica melhorada. Adicionalmente, estações geomagnéticas dentro de uma grande área da América do Sul, envolvendo a área de coerência de Santa Maria, apresentarão, em princípio, flutuações magnéticas com semelhança nos registros.
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