Evaluation of plasma convection models and their effect on the high-latitude ionosphere

Empirical models for the high-latitude plasma convection are now being used for space weather applications, and therefore, it is important to determine the extent to which they can reproduce instantaneous convection patterns. To address this issue, we adopted the Weimer convection model as the standard. Then, cross-track ion drift velocities measured by the Defense Meteorological Satellite Program's (DMSP) F13 satellite were compared to the corresponding velocities obtained from the Weimer model. Nearly a full year of DMSP F13 data was used in the study. The results indicate that the Weimer model was able to capture real (instantaneous) convection features in only about 6% of the satellite crossings.; Currently, the most widely used technique for obtaining real-time convection patterns is the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) technique. However, it is not certain whether or not data assimilation techniques improve on statistical models. To address this issue, we repeated the same comparison discussed above, but this time using AMIE deduced convection patterns instead of Weimer patterns. The comparisons indicate that the AMIE patterns adequately represented the DMSP observations about 32% of the time, which is a significant improvement over statistical convection patterns (6% of the time).; Furthermore, data assimilation models for the high-latitude convection have not been tested systematically as inputs to physics-based ionosphere forecast models. To address this issue, we used AMIE deduced convection patterns as inputs to a physics-based ionosphere forecast model. Then, we compared the plasma densities obtained from the model with corresponding in situ DMSP measured values. The comparisons were conducted for a one-year data set of DMSP F13 in situ measured plasma densities at 840 Km (satellite altitude). Our systematic Model/Data plasma density comparisons indicate that when a zero magnetospheric downward heat flux is assumed at the upper boundary of the model, on the average, the model underestimates the measured plasma densities by a factor of 2. Good Model/Data plasma density comparisons are achieved when a constant heat flow of about -1.0 x 1010 ev cm -2 s-1 is assumed at the upper boundary of the model.