Table 1. Summary of data selection criteria. Here, a_m and D_st are magnetic indices, IMF-By and IMF-Bz are the vector components of the interplanetary magnetic field in Geocentric Solar Magnetospheric (GSM) coordinates at the bow shock (http://omniweb.gsfc.nasa.gov/hw.html) and E_m is the merging electric field (Kan and Lee, 1979). By mid latitudes we mean track segments covering −60° to 60° geomagnetic latitude and high latitudes refers to overlapping tracks at < −50° and >50° geomagnetic latitude.

From: NOAA/NGDC candidate models for the 11th generation International Geomagnetic Reference Field and the concurrent release of the 6th generation Pomme magnetic model