Fig. 8
From: Solar and lunar daily geomagnetic variations and their equivalent current systems observed by Swarm
Swarm equivalent Sq current systems obtained from quiet-time magnetic observations by Swarm A and B during a the northern hemisphere summer (April–September) and b northern hemisphere winter (October–March) of 2017–2020. The results are presented for (left) 04:00–12:00 UT when the Euro-African/Central Asian sector is on the dayside, (middle) 12:00–20:00 UT when the American sector is on the dayside and (right) 20:00–04:00 UT when the Far Eastern/Pacific sector sector is on the dayside. In each of a and b, the upper panels show Swarm internal current systems, and the lower panels show Swarm external current systems. Contour steps are 5 kA