Speaker
Mr
Robert Ridgway
(University of Calgary)
Description
Plasma density in the outer terrestrial magnetosphere is highly
variable, both in space and time. Spacecraft observations are very
sparse, and photoelectric charging makes direct in-situ measurements
extremely challenging. In this report we present a new remote sensing
method which could be a significant source of information about
conditions in the dayside magnetosphere.
This technique uses a novel approach to travel-time magnetoseismology
based on the relationship between solar wind pressure and magnetospheric
currents. Travel-time magnetoseismology has had previous success in the
inner magnetosphere and our approach adapts it for use for the outer
magnetosphere. Observed time delays between solar wind forcing and
response at geostationary orbit are attributed to compressional mode
propagation in the equatorial plane. Alfvén speeds are modeled using a
dipole geomagnetic field and plasma density profiles from the IGRF and
Gallagher et al. Preliminary results show very good agreement between
the model and observations. Future work will include the application of
inversion techniques to recover 2D maps of equatorial plasma density in
the dayside magnetosphere.
Primary author
Mr
Robert Ridgway
(University of Calgary)
Co-author
Prof.
Brian Jackel
(University of Calgary)
