Correlations between solar, interplanetary medium parameters and geomagnetic activity proxies in 27-day averages (a Bartels’ rotation) were analysed for the 2009-2016 time interval. In this analysis, two new proxies were considered: 1) B ZS GSM, calculated as the daily percentage of the IMF southward component along the GSM Z-axis and then averaged every 27 days; 2) four magnetospheric indices (T-indices), calculated from the local North-South (X) contributions of the magnetosphere's cross-tail (TAIL), the symmetric ring current (SRC), the partial ring current (PRC) and the Birkeland current (FAC), derived from Tsyganenko and Sitnov 2005 (TS05) semi-empirical magnetospheric model. Our results suggest that, among the parameters tested in this study, solar facular areas, interplanetary magnetic field intensity and new proxies derived from TS05 model could be taken into account in an empirical model, with a 27-day resolution, to explain geomagnetic activity felt on the Earth's surface in terms of solar surface features and the IMF condition. We further retrieve a clear annual oscillation in series of 27-day-mean values of toward/away asymmetries of geomagnetic activity indices, which can be interpreted in the light of Russell-McPherron hypothesis for the semiannual variation of geomagnetic activity.

La Universidad Nacional Autónoma de Honduras instalará el Primer Observatorio Magnético de Honduras, para capturar las fuentes naturales del vector de campo magnético local. Proponemos una metodología para analizar sus datos, comparándolos con datos de observatorios cercanos, con el Modelo de Campo Geomagnético de Referencia Internacional, con el modelo semi-empírico de magnetosfera terrestre de Tsyganenko, N. y Sitnov, M., 2005. La componente geomagnética local horizontal (H−) es calculada para las coordenadas del Observatorio Astronómico Centroamericano de Suyapa, Tegucigalpa, Honduras (TEG-HTSY ), en el intervalo temporal 2010 – 2013, utilizando los modelos. Para el mismo intervalo temporal, se extrae la componente H− local del Observatorio Chiripa, Costa Rica (CRP-H), y su variación diaria en días calmos (Sq-H), empleando los días calmos internacionales. Se calculan los coeficientes de correlación de Pearson entre TEG-HTSY y CRP−H. Las mejores correlaciones se obtienen en días con índice planetario Kp < 4, cuando Sq-H y la variación diurna son removidas de CRP-H y de TEG-HTSY , respectivamente. Un modelo (NOCSq) es elaborado a partir del Sq-H de Chiripa, empleando funciones ortogonales empíricas (EOF). Al proyectar sobre los EOF las matrices de corrientes magnetosféricas de Tegucigalpa en días calmos, estas representan porcentajes considerables de los EOF, en el intervalo 12,00 – 24,00 hora local.

Correlations between solar, interplanetary medium parameters and geomagnetic activity proxies in 27-day averages (a Bartels' rotation) were analysed for the 2009-2016 time interval. In this analysis, two new proxies were considered: 1) B ZS GSM, calculated as the daily percentage of the IMF southward component along the GSM Z-axis and then averaged every 27 days; 2) four magnetospheric indices (T-indices), calculated from the local North-South

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