Quantifying the Impact of Dynamic Storm-Time Exospheric Density on
Plasmaspheric Refilling
Abstract
As soon as the outer plasmasphere gets eroded during geomagnetic storms,
the greatly depleted plasmasphere is replenished by cold, dense plasma
from the ionosphere. A strong correlation has been revealed between
plasmaspheric refilling rates and ambient densities in the topside
ionosphere and exosphere, particularly that of atomic hydrogen (H).
Although measurements of H airglow emission at plasmaspheric altitudes
exhibit storm-time response, temporally static distributions have
typically been assumed in the H density in plasmasphere modeling. In
this presentation, we evaluate the impact of a realistic distribution of
the dynamic H density on the plasmaspheric refilling rate during the
geomagnetic storm on March 17, 2013. The temporal and spatial evolution
of the plasmaspheric density is calculated by using the
Ionosphere-Plasmasphere Electrodynamics (IPE) model, which is driven by
a global, 3-D, and time-dependent H density distribution reconstructed
from the exospheric remote sensing measurements by NASA’s TWINS and
TIMED missions. We quantify the spatial and temporal scales of the
refilling rate and its correlation with H densities.