Browsing by Author "Huba, J."

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    CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge for systematic assessment of ionosphere/thermosphere models: NmF2, hmF2, and vertical drift using ground‐based observations
    (American Geophysical Union, 2011-12-31) Shim, J. S.; Kuznetsova, M.; Rastätter, L.; Hesse, M.; Bilitza, D.; Butala, M.; Codrescu, M.; Emery, B.; Foster, B.; Fuller-Rowell, T.; Huba, J.; Mannucci, A. J.; Pi, X.; Ridley, A.; Scherliess, L.; Schunk, R. W.; Stephens, P.; Thompson, D. C.; Zhu, L.; Anderson, D.; Chau Chong Shing, Jorge Luis; Sojka, J. J.; Rideout, B.
    Objective quantification of model performance based on metrics helps us evaluate the current state of space physics modeling capability, address differences among various modeling approaches, and track model improvements over time. The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) Electrodynamics Thermosphere Ionosphere (ETI) Challenge was initiated in 2009 to assess accuracy of various ionosphere/thermosphere models in reproducing ionosphere and thermosphere parameters. A total of nine events and five physical parameters were selected to compare between model outputs and observations. The nine events included two strong and one moderate geomagnetic storm events from GEM Challenge events and three moderate storms and three quiet periods from the first half of the International Polar Year (IPY) campaign, which lasted for 2 years, from March 2007 to March 2009. The five physical parameters selected were NmF2 and hmF2 from ISRs and LEO satellites such as CHAMP and COSMIC, vertical drifts at Jicamarca, and electron and neutral densities along the track of the CHAMP satellite. For this study, four different metrics and up to 10 models were used. In this paper, we focus on preliminary results of the study using ground‐based measurements, which include NmF2 and hmF2 from Incoherent Scatter Radars (ISRs), and vertical drifts at Jicamarca. The results show that the model performance strongly depends on the type of metrics used, and thus no model is ranked top for all used metrics. The analysis further indicates that performance of the model also varies with latitude and geomagnetic activity level.
    Palabras clave:IonosphereModel validationThermosphere
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    Systematic evaluation of ionosphere/thermosphere (UT) models: CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge (2009–2010)
    (American Geophysical Union, 2014-03) Shim, J. S.; Kuznetsova, M.; Rastätter, L.; Bilitza, D.; Butala, M.; Codrescu, M.; Emery, B. A.; Foster, B.; Fuller‐Rowell, T. J.; Huba, J.; Mannucci, A. J.; Pi, X.; Ridley, A.; Scherliess, L.; Schunk, R. W; Sojka, J. J.; Stephens, P.; Thompson, D. C.; Weimer, D.; Zhu, L.; Anderson, D.; Chau Chong Shing, Jorge Luis; Sutton, E.
    In order to model and predict the weather of the near‐Earth space environment, it is necessary to understand the important coupling mechanisms from the surface of the Sun to the Earth's ionosphere, including its coupling with the atmosphere below. This chapter reports the simulations of the mid‐latitude to low‐latitude ionosphere. Multiday simulations during the Whole Heliosphere Interval (WHI) 2008 are performed using two versions of SAMI3 model: (1) SAMI3 with externally specified E X B drifts and (2) SAMI3 with a potential solver to self‐consistently specify electric fields. The results are compared with GPS‐derived global total electron content (TEC) maps. The chapter details the E X B drifts calculated by the self‐consistent SAMI3 and compares these results with an empirical model. It provides initial results for a multi‐year run of the descending phase of Solar Cycle 23 to illustrate the broader range of Integrated Sun‐Earth System (ISES) activity underway
    Palabras clave:IonosphereElectric fieldsSpatial environment