Location
Yosemite National Park
Start Date
2-12-2014 5:25 PM
End Date
2-12-2014 5:40 PM
Description
The NRL SAMI3 ionosphere/plasmasphere code[1] has shown that the plasmasphere undergoes diurnal oscillations[2]. We find that those oscillations are consistent with variations found in in situ IMAGE/RPI density measurements during a quiet-time refilling event, 2001 February 01-05 and that the nature of the oscillations is strongly affected by thermospheric winds. The SAMI3 ionosphere code includes 7 ion species (H+, He+, O+, N+, O2+, N2+, NO+), each treated as a separate fluid, with temperature equations being solved for H+, He+, O+ and e-. We include a Weimer potential at high latitudes, driven by the solar wind, and the self-consistent dynamo potential at midto- low latitudes, driven by specified winds, such as the HWM07 or HWM93 empirical models or the TIMEGCM thermosphere model. During this quiet-time event, we find that the shape of the plasmasphere at any given time varies significantly with the wind model. In all cases, however, the diurnal oscillations persist and a similar degree of model-data agreement is found. [1] Huba, J. and J. Krall, 2013, ``Modeling the plasmasphere with SAMI3'', Geophys. Res. Lett. 40, 6-10, doi:10.1029/2012GL054300 [2] Krall, J., and J. D. Huba, 2013, ``SAMI3 simulation of plasmasphere refilling'', Geophys. Res. Lett., 40, 2484-2488, doi:10.1002/GRL.50458 Research supported by NRL base funds and the NASA LWS program.
How the Ionosphere-Thermosphere System Shapes the Quiet-Time Plasmasphere
Yosemite National Park
The NRL SAMI3 ionosphere/plasmasphere code[1] has shown that the plasmasphere undergoes diurnal oscillations[2]. We find that those oscillations are consistent with variations found in in situ IMAGE/RPI density measurements during a quiet-time refilling event, 2001 February 01-05 and that the nature of the oscillations is strongly affected by thermospheric winds. The SAMI3 ionosphere code includes 7 ion species (H+, He+, O+, N+, O2+, N2+, NO+), each treated as a separate fluid, with temperature equations being solved for H+, He+, O+ and e-. We include a Weimer potential at high latitudes, driven by the solar wind, and the self-consistent dynamo potential at midto- low latitudes, driven by specified winds, such as the HWM07 or HWM93 empirical models or the TIMEGCM thermosphere model. During this quiet-time event, we find that the shape of the plasmasphere at any given time varies significantly with the wind model. In all cases, however, the diurnal oscillations persist and a similar degree of model-data agreement is found. [1] Huba, J. and J. Krall, 2013, ``Modeling the plasmasphere with SAMI3'', Geophys. Res. Lett. 40, 6-10, doi:10.1029/2012GL054300 [2] Krall, J., and J. D. Huba, 2013, ``SAMI3 simulation of plasmasphere refilling'', Geophys. Res. Lett., 40, 2484-2488, doi:10.1002/GRL.50458 Research supported by NRL base funds and the NASA LWS program.