Ultra Low Frequency Waves and their Association with Magnetic Substorms and Expansion Phase Onset

• Author / Creator

  Murphy, Kyle R.

• This thesis concerns the study of Ultra Low Frequency (ULF) waves during magnetospheric substorms. A wavelet algorithm which characterises magnetic ULF waves during substorm onset is presented. The algorithm is validated by comparing the spatial and temporal location of ULF wave onset to space-based observations of the aurora. It is demonstrated that the onset of ULF wave power expands coherently away from an ionospheric epicentre during the substorm expansion phase.
  Further, a case study of the time-domain causality of magnetotail plasma flows and ULF wave Pi2 pulsations is presented. Although highly correlated, it is demonstrated that the plasma flows cannot directly drive the ground magnetic waveforms but may be indirectly linked via a common source.
  Finally, results from a statistical study of ULF wave power during onset are presented. It is concluded that there is no statistical difference between historical sub-classifications of ULF waves observed during substorms.

• Subjects / Keywords

  • Substorm Timing
  • Ultra Low Frequency Waves
  • Substorms
  • Expansion Phase onset

• Graduation date

  Fall 2009

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R31W4N

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.