Paper#: 139
Poster #:
Session Name: Workshop 1C: High Latitude Processes
Room: West Ballroom
Day: Monday
Time: 4:10-4:30 p.m.
Abstract Title: Multipoint Optical Remote Sensing of the State of the Inner Magnetosphere
PresentSurname: Donovan, E.
All Authors: E. Donovan, N. Nicholson, B. Jackel, I. Voronkov, T. Sotirelis
Abstract : The ion isotropy boundary (IB) marks the equatorward termination of significant central plasma sheet ion precipitation. It is easily identified in data from in situ instruments that provide quantitative measurements of particle energy flux with pitch angle resolution. The latitude of the IB is highly correlated with the inclination of the geomagnetic field at geosynchronous orbit. Primarily on this basis, Sergeev and Gvozdevsky [1995] argued that the IB-latitude at local midnight is a robust indicator of the state of the inner magnetosphere, and developed the MT-index. The IB is closely related to the b2i boundary, which is routinely identified in DMSP ion data [Newell et al., 1998]. We have developed a proxy (called the ``optical b2i boundary'') for the b2i boundary using meridian scanning photometer (MSP) proton auroral data, and demonstrated both its correspondence to the DMSP b2i boundary and its correlation with the inclination of the geomagnetic field at geosynchronous orbit [Donovan et al., 2002]. Using several photometers, as well as geosynchronous magnetic field data, we now have the capability to continuously monitor the state of the inner magnetosphere across several hours of local time, with time resolution on the order of one minute, for periods of several hours or longer. This is a powerful tool, with clear applications to the study of substorms.