Work

Numerical Investigations of Low‐Latitude Ground Magnetic Fields Due To Cavity Mode Oscillations

Year: 2026

Type: article

Abstract: 33 Pi2 oscillations have been known to be associated with cavity mode oscillations (CMOs) in 34 the inner magnetosphere at low latitudes. CMOs can also be excited by interplanetary shocks 35 on the dayside. We present results from a global linear MHD wave model in spherical 36 coordinates that allows us to analyse these waves at equatorial latitudes. We see that the 37 model reproduces some of the principal CMO harmonics. The standing wave cavity modes 38 are set up due to a dense plasmasphere. The CMOs associated with interplanetary shocks are 39 compared with ground observations from the EMMA array at mid-latitudes. In accordance 40 with observations of Pi2 pulsations, we also see a small phase difference between 41 compressional mode Alfvén waves at midnight at low altitudes and on the noon ground, both 42 at equatorial latitudes. This supports the finding that upon being excited in the nightside inner 43 magnetosphere, these waves travel quickly around to the dayside. We compare our results to

Source: Journal of Geophysical Research Space Physics

DOI: 10.1029/2025ja034346

Authors: K. Majmudar, R. L. Lysak, K. Takahashi, Khilav Majmudar

Institutions: University of Minnesota, Johns Hopkins University Applied Physics Laboratory

Language: English

Topic: Ionosphere and magnetosphere dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,070

Funders: National Science Foundation, National Aeronautics and Space Administration, University of Minnesota