The Comparison of Lunar Tidal Characteristics in the Low‐Latitudinal Ionosphere Between East Asian and American Sectors During Stratospheric Sudden Warming Events: 2009–2018

Abstract

Longitudinal differences of low‐latitudinal ionospheric responses during five major, four minor, and a none‐stratospheric sudden warming (SSW) winters from 2009 to 2018 between East Asian and American sectors are studied with total electron content (TEC). The time‐shifted semidiurnal (TS) pattern and the amplitude (AM2), phase angle (PAM2), and relative strength (RSM2) of the lunar semidiurnal tide (M2) harmonic in TEC are compared between the two sectors. Main results are as follows: (1) TS patterns, AM2,and RSM2 tend to be more discernable or larger in the American sector than in the East Asian sector. (2) TS patterns and PAM2 correspond well with the moon phase, and the occurrence of TS patterns coincides well with the enhancement of AM2 and RSM2. (3) Such patterns sometimes occur before the polar peak warming and experience several cycles during one event, but the most significant one tends to follow the peak warming. These characteristics are most distinct during major events with low solar activities. Our results support the mechanism that TS patterns in low‐latitudinal ionosphere parameters are due to enhanced lunitidal effects on the E region dynamo. Besides, changes in temperature and wind during SSWs can also contribute to the generation of TS signatures. Longitudinal differences in TEC suggest that the M2 influence on the low‐latitudinal ionosphere tends to be more prominent in the American sector than in the East Asian sector during SSWs. These differences probably result from a combined effect of the longitudinal variety in atmospheric (especially tidal) and electrodynamic processes.

Longitudinal and Interhemispheric Ionospheric Response to 2009 and 2013 SSW Events in the African‐European and Indian‐East Asian Sectors

“…Similar TEC behavior is also observed in the present study at low latitude stations. Recently, Liu et al (2019) studied low‐latitude ionospheric response to SSW events during 2009–2018 and found that time‐shifted semidiurnal (TS) patterns in TEC can occur before the peak warming of SSW. Fang et al (2012) using the WAM simulations initialized with assimilated measured data and the CTIPe model simulations studied the ionospheric response to the 2009 SSW event.…”

The Latitudinal Variation and Hemispheric Asymmetry of the Ionospheric Lunitidal Signatures in the American Sector During Major Sudden Stratospheric Warming Events

“…10.1029/2020JA028859 6 of 11 the E-region dynamo and the equatorial plasma fountain it creates (Fejer et al, 2010;Goncharenko, Chan, et al, 2010;Goncharenko, Coster, et al, 2010;J. Liu et al, 2019;Pedatella et al, 2012Pedatella et al, , 2014.…”

September 2019 Antarctic Sudden Stratospheric Warming: Quasi‐6‐Day Wave Burst and Ionospheric Effects

“…Forbes and Zhang (2012) argued that the large semidiurnal lunar tide observed during the January 2009 SSW can arise from resonant amplification associated with the atmospheric Pekeris mode. Enhanced lunar tidal perturbations in the equatorial ionosphere have been reported for a number of SSW events (Fejer et al, 2011;Liu et al, 2019;Siddiqui et al, 2015Siddiqui et al, , 2018Park et al, 2012).…”