Observations and model predictions of substorm auroral asymmetries in the conjugate hemispheres

Abstract

Based on imaging data from the Polar VIS Earth the camera and the IMAGE-FUV instruments we have documented how the IMF orientation and the dipole tilt angle act as the main and the secondary controlling factors of the relative displacement of the aurora in the conjugate hemispheres. Comparing our results with the asymmetries predicted by recent empirical magnetospheric models, we show that the assumed partial penetration of the IMF into the magnetosphere is clearly supported by observations, but the modeled conjugate shifts were found to be an order of magnitude smaller than the observed ones. Copyright 2005 by the American Geophysical Union.