Title page for ETD etd-04012011-110034


Type of Document Dissertation
Author Wilder, Frederick Durand
URN etd-04012011-110034
Title The Non-Linear Electrodynamic Coupling Between the Solar Wind, Magnetosphere and Ionosphere
Degree PhD
Department Electrical and Computer Engineering
Advisory Committee
Advisor Name Title
Clauer, C. Robert Committee Chair
Baker, Joseph B. H. Committee Member
Pratt, Timothy J. Committee Member
Ruohoniemi, J. Michael Committee Member
Scales, Wayne A. Committee Member
Simonetti, John H. Committee Member
Keywords
  • Solar Wind
  • Ionosphere
  • Magnetosphere
  • Electromagnetics
  • Plasma Physics
Date of Defense 2011-03-29
Availability unrestricted
Abstract
The polar electric potential imposed on the ionosphere by coupling between the

earth’s magnetosphere and the solar wind has been shown to have a non-linear response

to the interplanetary electric field (IEF). This dissertation presents an empirical

study of this polar cap potential saturation phenomenon. First, the saturation of

the reverse convection potential under northward is demonstrated using bin-averaged

SuperDARN data. Then, the saturation reverse convection potential is shown to saturate

at a higher value at higher solar wind plasma beta. The reverse convection

flow velocity is then compared with cross-polar cap flows under southward IMF under

summer, winter and equinox conditions. It is demonstrated that the reverse

convection flow exhibits the opposite seasonal behavior to cross polar cap flow under

southward IMF. Then, an interhemispheric case study is performed to provide an

explanation for the seasonal behavior of the reverse convection potential. It is found

using DMSP particle precipitation data that the reverse convection cells in the winter

circulate at least partially on closed field lines. Finally, SuperDARN and DMSP

data are merged to provide polar cap potential measurements for a statistical study

of polar cap potential saturation under southward IMF. It is found that the extent

of polar cap potential saturation increases with increasing Alfvenic Mach number,

and has no significant relation to Alfven wing transmission coefficient or solar wind

dynamic pressure.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Wilder_FD_D_2011.pdf 171.23 Mb 13:12:43 06:47:41 05:56:43 02:58:21 00:15:13

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.