Model and Observation Comparison of the Universal Time and IMF By Dependence of the Ionospheric Polar Hole
Advances in Space Research
The polar ionospheric F-region often exhibits regions of marked density depletion. These depletions have been observed by a variety of polar orbiting ionospheric satellites over a full range of solar cycle, season, magnetic activity, and universal time (UT). An empirical model of these observations has recently been developed to describe the polar depletion dependence on these parameters. Specifically, the dependence has been defined as a function of F10.7 (solar), summer or winter, Kp (magnetic), and UT. Polar cap depletions have also been predicted /1, 2/ and are, hence, present in physical models of the high latitude ionosphere. Using the Utah State University Time Dependent Ionospheric Model (TDIM) the predicted polar depletion characteristics are compared with those described by the above empirical model. In addition, the TDIM is used to predict the IMF By dependence of the polar hole feature.
Sojka, J. J., R. W. Schunk, W. R. Hoegy, and J. M. Grebowsky, Model and observation comparison of the universal time and IMF By dependence of the ionospheric polar hole, Adv. Space Res., 11, 39–42, 1991.