Multi-spectral optical imaging of the spatiotemporal dynamics of ionospheric intermittent turbulence

Abstract

Equatorial plasma depletions have significant impact on radio wave propagation in the upper atmosphere, causing rapid fluctuations in the power of radio signals used in telecommunication and GPS navigation, thus playing a crucial role in space weather impacts. Complex structuring and self-organization of equatorial plasma depletions involving bifurcation, connection, disconnection and reconnection are the signatures of nonlinear evolution of interchange instability and secondary instabilities, responsible for the generation of coherent structures and turbulence in the ionosphere. The aims of this paper are three-fold: (1) to report the first optical imaging of reconnection of equatorial plasma depletions in the South Atlantic Magnetic Anomaly, (2) to investigate the optical imaging of equatorial ionospheric intermittent turbulence, and (3) to compare nonlinear characteristics of optical imaging of equatorial plasma depletions for two different altitudes at same times. We show that the degree of spatiotemporal complexity of ionospheric intermittent turbulence can be quantified by nonlinear studies of optical images, confirming the duality of amplitude-phase synchronization in multiscale interactions. By decomposing the analyses into North-South and East-West directions we show that the degree of non-Gaussianity, intermittency and multifractality is stronger in the North-South direction, confirming the anisotropic nature of the interchange instability. In particular, by using simultaneous observation of multi-spectral all-sky emissions from two different heights we show that the degree of non-Gaussianity and intermittency in the bottomside F-region ionosphere is stronger than the peak F-region ionosphere. Our results are confirmed by two sets of observations on the nights of 28 September 2002 and 9 November 2002.

Disconnection and Reconnection in Plasma Bubbles Observed by OI 630 nm Airglow Images From Cariri Observatory

“…Chian et al (2018) extended the observational study of Sahai et al (2006) and reported airglow images of neighboring plasma bubbles disconnecting and reconnecting. In the airglow images reported by Chian et al (2018), they observed that the first disconnection occurs on the east side and after some time, the detached part is captured by an adjacent plasma bubble on the west side in the image.…”

“…It is worth mentioning that the airglow images reported by Chian et al. (2018) were obtained on 28 September 2002 in another location in Brazil.…”

Airglow Imaging Observations of Plasma Blobs: Merging and Bifurcation during Solar Minimum over Tropical Region

“…Refs. [12,17] also reported disconnection and reconnection of plasma bubbles. The reconnection features of the plasma bubbles observed are similar to the plasma bubbles' ionospheric electrostatic reconnection reported by [15].…”

Observation of an Intriguing Equatorial Plasma Bubble Event Over Indian Sector

“…Many researchers have studied the dynamics of EPBs in the context of their zonal drifts, occurrence statistics, morphological evolution etc (e.g., Chian et al., 2018; Gurav et al., 2019; Kakad et al., 2017; Sharma et al., 2017 etc.). The EPBs frequently occur in high solar activity but during low solar activity period a stronger perturbation is needed for their development (e.g., Buhari et al., 2017) which could either be of wave‐like seed of lower atmospheric origin (e.g., Taori et al., 2011) or of electrical origin such as magnetic disturbance (e.g., Sripathi et al., 2018).…”