Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM

摘要: Abstract. Cluster/EDI electron drift observations above the Northern and Southern polar cap areas for more than seven a half years (2001–2008) have been used to derive statistical model of high-latitude electric potential distribution summer conditions. Based on pattern different orientations interplanetary magnetic field (IMF) in GSM y-z-plane, basic convection (BCP) were derived, that represent main characteristics dependence IMF. The BCPs comprise IMF-independent as well patterns, which describe positive negative IMFBz IMFBy variations. full set allows spatial temporal variation (ionospheric convection) any solar wind IMF condition near Earth's magnetopause within reasonable ranges. comparison with IZMEM ionospheric model, was derived from ground-based magnetometer observations, shows good agreement patterns its According models, there is two-cell antisunward northward IMFBz+≤2 nT, while increasing IMFBz+ appears region sunward daytime sector, assumes form two additional cells between them IMFBz+≈4–5 nT. This results four-cell convection. In ±IMFBy contribution during sufficiently strong conditions, transformation three-cell takes place.