English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Pi 2 pulsations at low latitudes are examined with magnetic fields data at the 210° magnetic meridian (MM) stations in 1991. Due to high degree of coherence over most latitudes, 68 low-latitude Pi 2 events at the 210° MM stations are identified with reference to same waveforms on the magnetogram at Lunping (189.5° MM, L = 1.06). With spectral power analysis, the ratio of the first four harmonic frequencies of low-latitude Pi 2 pulsations is about 1: (1.7 ± 0.1): (2.3 ± 0.1): (2.9 ± 0.1). By using abox model for the inner magnetosphere, the cold linearized MHD wave equations are studied with realistic Alfven speed profile for nonuniform ambient magnetic fields. With appropriate parameters to depict the magnetospheric environments during the aforementioned period, numerical results are acquired with the fourth order Runge-Kutta method. It is found that the ratio of the first four harmonic frequencies of plasmaspheric cavity resonances is about 1: 1.7: 2.4: 3.1 that is consistent with data analysis. This suggests that low-latitude Pi 2 pulsations at the 210° MM stations may be plasmaspheric cavity resonances driven by fast compressional waves owing to the impulsive source at the magnetotail.

Spectral power of low-latitude Pi 2 pulsations at the 210° magnetic meridian stations and plasmaspheric cavity resonances