Electron density models for assessment studies - New developments

The family of electron density models developed at Graz and Trieste, NeQuick, COST-prof and NeUoG-plas, allow now - to be updated with actual data from various sources, - to be adjusted to disturbed conditions, - to be combined with smaller scale models, - to calculate a variety of propagation effects along arbitrarily chosen raypaths. The models are profilers which use the peaks of the E, the F1 and the F2 layers as anchor points. The models use identical formulations for the height region 100 km to the F2 peak but differ in complexity for the topside of the F region. NeUoG-plas has a magnetic field oriented plasmasphere above the ionosphere. For slant ray path applications it is not sufficient to update models at one point: ionospheric conditions have to be taken into account along the entire ray path. Therefore our family of models uses data grids for anchor point conditions. For modeling of positive storm conditions an additional grid has been introduced which gives information about a topside inflation factor. The grids are equidistant in geographic coordinates (spacing: 2.5 degrees in latitude, 5 degrees in longitude). Two dimensional third order interpolation is used to find values between the gridpoints. Combination with smaller scale models is considered as a modulation of the larger scale models: M(h, Φ, λ) = L(h, Φ, λ)T(h, Φ, λ)S(h, Φ, λ) (M: resulting electron density model, L: large scale model (member of our model family), T, S: modulations, e.g., for the main trough and for TIDs. h: height, Φ: geogr. latitude, λ: geogr. longitude).