Vertical Coupling From the Lower Atmosphere to the Ionosphere: Observations Inferred From Indian MST Radar, GPS Radiosonde, Ionosonde, Magnetometer, OLR (NOAA), and SABER/TIMED Instrument Over Gadanki

Abstract

Simultaneous wind observations from Mesosphere Stratosphere Troposphere (MST) radar collectively with Global Positioning System (GPS) radiosonde over Gadanki, covering altitude range of 3.6–20 km (January–December 2009; 365 days), divulge the propagation of lower atmospheric waves up to the ionosphere. It is combined with temperature data (20–110 km) observed from Sounding of the Atmosphere using the Broadband Emission Radiometry (SABER) instrument onboard Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, ionosonde observations, and daily Outgoing Longwave Radiation (OLR) data acquired from the National Ocean and Atmospheric Administration (NOAA; centered around Gadanki [13.5°N, 79.2°E]) for the same time period. Long‐period oscillations with periodicities of ~64, ~32, and ~21 days are witnessed along with the well‐known oscillations of ~16, ~6.4, and ~5.3 days. Most of the long‐period oscillations are dominantly perceived during the summer months (April–June 2009), which can even exist up to September. These long‐period oscillations are found to propagate from lower tropospheric heights up to ionospheric heights with large vertical wavelengths (~300–400 km, in some cases) near to transition zones of atmospheric layers (e.g., tropopause, stratopause, and mesopause). Signatures of vertical coupling of atmosphere through large vertical wavelengths (indicating possible intraseasonal connections) is clearly observed in the equatorial electrojet current and the peak plasma frequencies of ionospheric layers (E and F regions). Noticeable reduction of the wave oscillations in spatial scale with upsurge in spatial damping is evidently visible, in the tropical stratosphere and mesosphere, which can be attributed to stratospheric ozone.

A Statistical Analysis of the Propagating Quasi 16‐Day Waves at High Latitudes and Their Response to Sudden Stratospheric Warmings From 2005 to 2018

“…As seen from Figure 3, the four wave modes all exhibit upward-propagating activities around 1 hPa, which indicates that although it is difficult, the quasi 16-day oscillations can still pass through this region. Ghosh et al (2019) suggested that the vertical wavelength of the quasi 16-day waves is large enough near the stratopause region, which ensures their propagation to higher altitudes even up to the ionosphere. Nevertheless, the mechanisms of the vertical propagating quasi 16-day waves from the stratosphere to the mesosphere need further investigations.…”

Anomalous Responses of the F2 Layer Over the Brazilian Equatorial Sector During a Counter Electrojet Event: A Case Study

“…The day‐to‐day variability in the ionosphere is a phenomenon that is directly connected to the internal and external processes that modify the structure of the atmosphere‐ionosphere‐magnetosphere (AIM) system, such as internal atmospheric waves (gravity, planetary, tidal, and acoustic waves) that propagate to the ionosphere from the lower height regions (see e.g., Abdu, Batista, et al., 2006; Abdu, Ramkumar et al., 2006; Ghosh et al., 2019) and the magnetospheric solar and geomagnetic external forcing from above during the occurrence of disturbance space weather events (e.g., Abdu et al., 2003, 2009; Batista et al., 1991; Brum et al., 2021; Garzón et al., 2011; Kelley, 1989; Kelley et al., 2003; Kikuchi et al., 2008; Santos et al., 2012, 2016a, 2016b; Sastri et al., 1993; Sobral et al., 1997, 2001). Independently of the origin of the perturbations that arrive in the ionosphere, the variability occurring during the evening to post‐sunset and night hours has gained special attention since the sunset electrodynamics processes play a fundamental role in the generation of important phenomena, such as the equatorial ionization anomaly and the plasma bubble irregularities (Abdu & Brum, 2009).…”

“…Using different instruments, Ghosh et al. (2019) observed a long‐period oscillation in the ionospheric parameters over Gadanki (13.5°N, 79.2°E, 6.5°N mag. lat.…”

Anomalous responses of the F 2 layer over the Brazilian equatorial sector during a counter electrojet event: a case study

“…The day-to-day variability in the ionosphere is a phenomenon that is directly connected to the internal and external processes that modify the structure of the atmosphere-ionosphere-magnetosphere (AIM) system, such as internal atmospheric waves (gravity, planetary, tidal, and acoustic waves) that propagate to the ionosphere from the lower height regions (see for example Abdu et al, 2006a,b;Ghosh et al 2019) and from the magnetospheric solar and geomagnetic external forcing from above during the occurrence of disturbance space weather events (e.g., Kelley 1989Kelley , 2003Sobral et al, 1997Sobral et al, , 2001Batista et al 1991;Abdu et al, 2003Santos et al, 2012Santos et al, , 2016aSastri et al, 1993;Kikuchi et al, 2008;Garzón et al, 2011;Brum et al, 2021). Independent of the origin of the perturbations that arrive in the ionosphere, the variability occurring during the evening to post-sunset and night hours have gained special attention since the sunset electrodynamics processes play a fundamental role in the generation of important phenomena, such as the equatorial ionization anomaly and the plasma bubble irregularities (Abdu and Brum, 2009).…”

“…Although the general behavior of the ionosphere can be determined predominantly by the solar and geomagnetic forcings, the propagation of the lower atmospheric waves up to the ionosphere can contribute significantly to this variability. Using different instruments, Ghosh et al (2019) for example, observed a long-period oscillation in the ionospheric parameters over the Gadanki (13.5 • N, 79.2 • E, 6.5 • N mag. lat.…”