@article{oai:nagoya.repo.nii.ac.jp:00028481,
 author = {Thomas, Neethal and Shiokawa, Kazuo and Vichare, Geeta},
 issue = {3},
 journal = {Journal of Geophysical Research: Space Physics},
 month = {Mar},
 note = {To understand the spatial features of low‐latitude Pi2 (6.6–25 mHz) pulsations, a comprehensive study is carried out for the first time using magnetic field measurements from a global network of low‐latitude ground stations (Mlat: ± 2°− 51°) and the Swarm multisatellites located simultaneously at day and night local times. We have investigated 1‐year data from 2014 and found 15 Pi2 events with coherent oscillations at satellite and ground. The Pi2 oscillations in the compressional, toroidal, and poloidal components at satellite and H, D, and Z components at ground are investigated by estimating its coherence, amplitude, and cross phase with respect to midnight ground H variations. The analogous pairs of magnetic field components (satellite compressional with ground H and satellite toroidal with ground D) above and below the ionosphere are found to have identical phase during night and opposite phase during day, indicating the magnetospheric and ionospheric sources for nighttime and daytime Pi2s, respectively. During nighttime, Pi2 oscillations identified in the poloidal component are found to oscillate in phase (out of phase) in the Southern (Northern) Hemisphere. At ground, the phase and amplitude of H showed significant change near the dawn terminator, whereas H oscillates mostly in phase with respect to midnight ground H at other local times. The oscillations in D component have phase reversal near midnight, dawn, dusk, and noon meridians with opposite hemispheres having opposite phase. These Pi2 characteristics observed globally at ground and at the topside ionosphere suggest that the sources for nighttime and daytime low‐latitude Pi2s are oscillating field‐aligned currents and ionospheric currents, respectively.},
 pages = {1966--1991},
 title = {Comprehensive Study of Low‐Latitude Pi2 Pulsations Using Observations From Multisatellite Swarm Mission and Global Network of Ground Observatories},
 volume = {124},
 year = {2019}
}