Multi-instrument analysis of L-band amplitude scintillation observed over the Eastern Arabian Peninsula

TL;DR

This study analyzes the spatial and temporal patterns of L-band amplitude scintillation caused by ionospheric irregularities over the Eastern Arabian Peninsula during 2020-2023, highlighting the influence of solar activity and seasonal variations.

Contribution

It provides a comprehensive multi-instrument analysis of ionospheric irregularities and scintillation characteristics during solar cycle 25, revealing new insights into their spatial distribution and temporal behavior.

Findings

Strong scintillation increased in 2023, correlating with solar activity.

Weak irregularities were widespread, strong ones concentrated southward.

Southward traveling ionospheric disturbances were observed during 2023 autumn equinox.

Abstract

This study investigates the spatial and temporal characteristics of L1 amplitude scintillation-causing ionospheric irregularities over the Eastern Arabian Peninsula during the ascending phase of solar cycle 25 (years 2020--2023). The temporal occurrences of weak and strong scintillation were separated by sunset, with weak scintillation observed predominantly pre-sunset during the winter solstice and strong scintillation observed mainly post-sunset during the autumnal equinox. Strong scintillation was much more pronounced in 2023 compared to the other three years, indicating a strong influence of solar activity. Spatially, weak-scintillation-causing irregularities exhibited a wide distribution in azimuth and elevation, while strong-scintillation-causing irregularities were concentrated southwards. The combined analysis of S4 and rate of total electron content index (ROTI) suggested that small-scale ionospheric irregularities were present in both pre- and post-sunset periods, while large-scale irregularities were only seen during the post-sunset period. Furthermore, the presence of southward traveling ionospheric disturbances (TIDs) during the 2023 autumnal equinox was confirmed with the total electron content anomaly ($\Delta\text{TEC}$), while the Ionospheric Bubble Index (IBI) provided by the Swarm mission was unable to confirm the presence of equatorial plasma bubbles during the same period. Observations from the FORMOSAT-7/COSMIC-2 mission indicated that strong-scintillation-causing irregularities were more prevalent under the F2-layer peak, while the weak-scintillation-causing irregularities were mostly observed at the E-layer, F2-layer, and above the F2-layer.