1. Deviren, M.N., Cor, I., Arikan, F. and Gulyaeva, T.L. (1) Hacettepe University, Turkey, arikan@hacettepe.edu.tr (2) IZMIRAN, Russia, gulyaeva@izmiran.ru GOAL : Develop a space weather risk index/indicator based on variability of ionospheric parameters computed from models. Candidates : Parameters calculated from ionospheric models. Variability of Ne, TEC, foF2, hmF2, Te, Ti, Diffusion coefficient, D and drift velocity, Composite Model of Current density, Conductivity,  Background ionospheric electric potential,  Models : IRI-Plas, NRL-MSIS, IGRF, HWM-93 1/5

2. Conservation of charge, Quasi-neutrality, Current density Conservation of Momentum Ambipolar diffusion coefficient and drift velocity Transport can include diffusion, neutral winds and vertical electromagnetic drift. Maxwell’s Equations: Consequence:, Define: Composite Current Density : 2/5

3. Gradient of Ne at 250 km, IRI-Plas 3/5 where is the ratio of gyrofrequency to collision frequency, and

4. 4/5

5. Drift Velocity,,over Turkey Conductivities, Collision frequencies, 5/5

6. The physical parameters of ionosphere, such as current density, drift velocity, diffusion coefficient, conductivity can be computed using ionospheric models. IRI-Plas can input GIM-TEC and update Ne, foF2 and hmF2. Spatio-Temporal Variability over the parameter maps can be obtained to indicate direction and magnitude of change. Electrostatic potential can be computed from: This study is supported by the joint grant of TUBITAK 112E568 and RFBR 13-02-91370-CT_a. References: Withers, P., Theoretical models of ionospheric electrodynamics and plasma transport, JGR-Space Physics, 113, A07301, 1-12, 2008. Banks, P.M., Kockarts, G., Aeronomy, Elsevier, New York, 1973. Rishbeth, H., Garriott, O.K., Introduction to Ionospheric Physics, Elsevier, New York, 1969. 6/5 Conclusion 41st COSPAR Scientific Assembly Special COSPAR C1.3 /PSW Session Regions of the Enhanced Risk for the Ionospheric Weather ‘Regions of the Enhanced Risk for the Ionospheric Weather’ 30 July – 7 August 2016, Istanbul, Turkey, MSO – Feza Arikan, DO – Tamara Gulyaeva. Your Contributions are Welcome!