5:15 PM - 6:30 PM
[MIS08-P07] Correlations between geomagnetic Sq external and internal equivalent current systems in East-Asia and Oceania regions
Keywords:Sq external current, Sq internal current, correlation, East-Asia and Oceania regions
In present work, the absolute values of geomagnetic three components (XYZ) data from 20 observatories in East-Asia and Oceania regions were used to investigate the correlations between the external and internal Sq current systems. The seasonal current models of D (northern winter) season, E (equinox) season, and J (northern summer) season have been constructed by SHA (Spherical Harmonic Analysis) respectively. The intra-seasonal correlations of the current vortex center parameters T (local time), Φ (latitude), J (current intensity) between the Sq equivalent internal and external currents are analyzed. The results show that (1) in the E season, the correlation of T is the highest, the square of correlation coefficients is R2=0.857 in the NH (northern hemisphere). (2) And in the local summer and winter, the correlation of J is the strongest. The square of correlation coefficients are R2= 0.490 and 0.778, respectively, and also in the NH.
The mechanism for different seasonal correlations of different current vortex center parameters between the external and internal current systems is roughly considered. In fact, as two parts of the same current system, solar activity, ionospheric conductivity, neutral wind field, geomagnetic field and so on affect the internal and external current systems. At the same time, the variations of internal current are also controlled by the conductivity of underground conductive circle in the upper mantle. [Schmucker 1970; Campbell 1987, Campbell and Schiffmacher, 1988].