[1] This paper addresses the effects of scintillation on high-latitude paths of propagation. To specify the high-latitude ionosphere environment as a time-dependent threedimensional distribution of the electron density, the first-principles ionospheric model UAF EPPIM (University of Alaska Fairbanks Eulerian Parallel Polar Ionosphere Model) is utilized. For the specification of time-varying small-scale irregularities, superimposed onto the background EPPIM, the full three-dimensional inverse power law spectrum is chosen. It is augmented with the introduction of the irregularities' aspect ratio for two mutually perpendicular directions: transverse (to the geomagnetic field) direction and for the longitudinal direction to the transverse one. This full description of the propagation environment, comprised of the ''background'' and ''irregularities'' components, is further merged with the propagation scintillation model to set up the computational suite, capable of modeling the scintillation effects. The parameters of the spectrum of the electron density fluctuations, as well as the models of meso-scale local polar structures (e.g., patches) are chosen empirically. The integrated simulator enables realistic predictions of the scintillation effects for high-latitude transionospheric propagation for a number of different propagation scenarios for GPS L-band and other UHF transionospheric signals. The specific scintillation effects, caused by ionospheric patches, are simulated.Citation: Maurits, S. A., V. E. Gherm, N. N. Zernov, and H. J. Strangeways (2008), Modeling of scintillation effects on highlatitude transionospheric paths using ionospheric model (UAF EPPIM) for background electron density specifications, Radio Sci., 43, RS4001,

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[1] The University of Alaska Fairbanks Eulerian Polar Parallel Ionospheric Model is a high-resolution model of the polar ionosphere that incorporates multiple ion species. This paper briefly describes this model and the implementation of the total variation diminishing (TVD) advection scheme. The model is based on an Eulerian framework. It is demonstrated that the minimal numerical diffusion of the TVD advection scheme is critical for maintaining ion density gradients with high-resolution Eulerian ionospheric models. The performance of this method is discussed and compared with an upwind numerical scheme. A sample model run for 24 October 2003 that simulates the formation of polar cap ionospheric structures is presented. The results using the TVD advection scheme are compared with the corner transport upwind advection scheme to demonstrate the advantage of the TVD method for simulating steep density gradients and small-scale density structures. These small-scale density features result from time-varying electric fields and are commonly observed using experimental techniques (e.g., incoherent scatter radar) in polar regions.Citation: Kulchitsky, A., S. Maurits, B. Watkins, and J. McAllister (2005), E Â B drift simulation in an Eulerian ionospheric model using the total variation diminishing numerical scheme,