Magnetotail flows near lunar orbit and their relation to substorms

We perform a five year statistical study of fast flows in the Earth's magnetotail observed by ARTEMIS to investigate their occurrence rate, dawn-dusk asymmetry and relation with magnetospheric substorms. Almost half of the observed flows are directed earthward and their percentage decreases with increasing flow speed. While no clear dawn-dusk asymmetry is observed for earthward directed flows, about 60% of the tailward flows occur in the dusk sector. For tailward flows this asymmetry is similar for different AL thresholds. However, earthward flows become strongly asymmetric towards dusk for higher AL thresholds. A correlation of flow events with the AL index also shows a clear correlation of tailward flows with a decrease in AL, while such a correlation can not be seen for earthward flows.