Investigation into the linear relationship between the AE, Dst and ap indices during different magnetic and solar activity conditions

There are numerous geomagnetic indices used in monitoring various magnetospheric and ionospheric phenomena. Some of the most widely used indices are the ap, AE and Dst. In this work, the relationship between these three geomagnetic indices is investigated at different levels of solar and magnetic activity. 3-h average data spanning 8-years were used-high (HSA), moderate (MSA) and low solar activity (LSA) periods cover the years 1999-2001, 2004-2005, and 2006, 2009-2010 respectively. All the investigated correlation pairs recorded the highest/lowest during the LSA/HSA periods. The ap/AE correlation was found to be highest ranging within 70-78 % at any solar activity. The ap versus AE and Dst multiple correlation reached 94.0, 92.1, and 89.2 % for HSA, MSA, and LSA conditions, respectively, and 72.1, 83.3, and 80.0 % for the main phase, recovery phase and quiet conditions respectively. Moreover, higher percentage correlations were observed for the ap/AE pair at any geomagnetic conditions than for the ap/Dst and AE/Dst pairs. The ring current index Dst is observed to have a greater influence on ap during geomagnetic storm periods.