Tuesday, 13 January 2009: 9:15 AM
A Statistical Comparison of Vertical TEC from Three Ionospheric Models
Room 126B (Phoenix Convention Center)
Total electron content (TEC) exhibits significant variations in both space and time depending upon latitude, longitude, solar cycle, UTC, and season; these variations can have potentially negative effects on communication and navigation users. Recently, three models have provided accurate results in reconstructing and or calculating real-time (or near real-time) vertical TEC values: the Utah State University-Global Assimilation of Ionospheric Measurements (USU-GAIM) Gauss-Markov Kalman Filter Model, the United States Total Electron Content (US-TEC) Model, and the Coupled Thermosphere Ionosphere Plasmasphere electrodynamics (CTIPe) Model. The present research offers a statistical comparison of the vertical TEC outputs from the previously mentioned models on both a global and local (over the continental US) scale during the month of July 2008. We present the average difference and root mean square difference (RMS difference) for three different model comparisons (e.g. – US-TEC vs. GAIM, US-TEC vs. CTIPe, and GAIM vs. CTIPe). We document certain model biases and the differences measured between corresponding data points among the models relative to each comparison. Two out of the three comparisons showed that the US-TEC model's bias predicted higher values of vertical TEC relative to the two other models, while the third comparison revealed a small bias in the CTIPe model to forecast greater vertical TEC values as compared to the GAIM model. By computing the RMS difference, we can better examine the source of these biases relative to the aforementioned model comparisons. This is the first step in documenting the biases, errors, and uncertainties associated with these three models.