High latitude ionospheric irregularity model

Modifications were made to the global scintillation model that was developed by Fremouw (Stanford Research Institute), to better represent recent high latitude scintillation data. These modifications were made primarily in the high latitude term of the model and include a provision for variation in the position of the scintillation boundary with respect to magnetic activity. The resulting model is compared with published curves of scintillation activity with respect to latitude and is found to produce a considerably better agreement with those curves than the original model. A modification of the model is made to represent the finding that the northern and southern polar regions of the scintillation activity are not symmetrical with respect to each other.