Penetration of magnetosonic waves into the plasmasphere observed by the Van Allen Probes

Author
Keywords
Abstract
During the small storm on 14\textendash15 April 2014, Van Allen Probe A measured a continuously distinct proton ring distribution and enhanced magnetosonic (MS) waves along its orbit outside the plasmapause. Inside the plasmasphere, strong MS waves were still present but the distinct proton ring distribution was falling steeply with distance. We adopt a sum of subtracted bi-Maxwellian components to model the observed proton ring distribution and simulate the wave trajectory and growth. MS waves at first propagate toward lower L shells outside the plasmasphere, with rapidly increasing path gains related to the continuous proton ring distribution. The waves then gradually cross the plasmapause into the deep plasmasphere, with almost unchanged path gains due to the falling proton ring distribution and higher ambient density. These results present the first report on how MS waves penetrate into the plasmasphere with the aid of the continuous proton ring distributions during weak geomagnetic activities.
Year of Publication
2015
Journal
Geophysical Research Letters
Date Published
09/2015
URL
http://onlinelibrary.wiley.com/wol1/doi/10.1002/2015GL065745/full
DOI
10.1002/2015GL065745