Response of the Ionosphere to the December 2006 Storm: CMIT Simulation

1
Response of the Ionosphere to the December 2006
Storm CMIT Simulation J. Lei1, W. Wang1, A. G.
Burns1, S. C. Solomon1, M. Wiltberger1 and H.
Spence2 1High Altitude Observatory, National
Center for Atmospheric Research 2Center for
Space Physics, Boston University
Abstract We present the ionospheric response to
the 14-15 December, 2006 geomagnetic storm using
the Coupled Magnetosphere Ionosphere Thermosphere
(CMIT) 2.0 model simulations and global
ionospheric maps of total electron content (TEC)
observations. These observations were provided by
the madrigal database at MITs Haystack
Observatory. The Thermosphere Ionosphere
Electrodynamics General Circulation Model
(TIEGCM) stand-alone model was also run to
compare with these GPS observations and CMIT
results. Here we have focused on comparisons
between these results and observations during the
initial phase of the storm, when the shock was
driving changes in geospace. Our results show
that CMIT 2.0 was able to capture the temporal
and spatial variations seen in the GPS TEC
observations. Furthermore, the agreement between
the GPS observations and the CMIT simulation was
much better than that between observations and
the stand-alone TIEGCM results.
CMIT 2.0 Coupling between
the NCAR TIEGCM and the Lyon-Fedder-Mobarry (LFM)
magnetospheric MHD model
Model/Data Comparison
GPS ?TEC
CMIT ?TEC
TIEGCM ?TEC
1600 UT
Solar/Geophysical Conditions
1800 UT
2000 UT
2200 UT
The solar wind speed (a), proton density (b),
interplanetary magnetic field By (c), Bz (d), AE
index (e), interplanetary electric field (f), Ap
and Dst index (g) during 13-15 December 2006. The
solar wind data from WIND are shifted by 30 min,
and the arrow in panel (g) indicates the time of
the sudden commencement of this storm.
Global maps of differential TEC between the
disturbance day (Dec. 14 ) and quiet day (Dec.
13) for the initial phase (1400-2300 UT on Dec.
14). Left panels TIEGCM stand-alone run middle
panels CMIT 2.0 simulation right panels GPS
observations. The unit of differential TEC is
TECu (1 TECu1016 electrons/m2 ).
Center for Integrated Space Weather Modeling
Annual Site Visit 5 June 2007