This project will improve current models of the Earth's magnetic field at high latitudes and at larger distances from the Earth than current models. The new model will include a model of the location of the magnetopause that depends on solar wind pressure and the interplanetary magnetic field (IMF). The twisting of the cross-tail current sheet in response to the By-component of the IMF will be included in the model as will the deep depression of the magnetic field in the magnetospheric cusp due to the diamagnetic effect of magnetosheath plasma. The model will be distributed to the scientific community via the National Space Science Data Center (NSSDC) web site.