IONISE: An Ionospheric Observational Network for Irregularity and Scintillation in East and Southeast Asia

Abstract

An Ionospheric Observational Network for Irregularity and Scintillation in East and Southeast Asia (IONISE) is developed to identify and study the short‐term and fine‐scale ionospheric variations over China. The IONISE network mainly includes three crossed chains of Beidou geostationary satellite total electron content (TEC)/scintillation receivers along 110°E, 23°N, and 40°N respectively, multistatic portable digital ionosondes and bistatic very high‐frequency radars. Based on the IONISE observations, we report some preliminary results of ionospheric disturbances and irregularities, including (1) initially generated and zonally drifting equatorial plasma bubbles and related scintillations, (2) traveling ionospheric disturbances from middle to low latitudes, (3) drift of strong sporadic E structures over a wide area of more than 1,000 km, (4) fine‐scale ionospheric perturbation and regional TEC gradient, and (5) general features of ionospheric response to geomagnetic storms. Possible mechanisms responsible for these ionospheric phenomena are discussed. The IONISE provides new data set for investigation on ionospheric disturbances of various scales in a broad region with dense observations along specific latitude/longitude.

Morphological Characteristics of Thousand‐Kilometer‐Scale Es Structures Over China

“…TEC measurements from more than 250 GNSS receivers of the Crustal Movement Observation Network of China (CMONOC; Aa et al, 2015) (Sun et al, 2020b). The time resolution of TEC data used in the present analysis is 30 s.…”

“…It is relevant to mention that at nighttime, the F-region irregularities and disturbances may mask the E-region irregularity structures in the TEC time series. (Sun et al, 2020b). The specular meteor observations by the all-sky meteor radars at Beijing, Wuhan, and Ledong were used to derive the neutral wind velocity at altitudes 80-100 km (Wang et al, 2019;Yu et al, 2013).…”

“…Using multiinstrument observations over low‐latitude China, Sun et al. (2020a, 2020b) found that the large‐scale drifting strong E s structures responsible for low latitude E‐region VHF radar backscatter echoes and L‐band scintillations were initially generated at higher latitudes.…”

Occurrences of Regional Strong Es Irregularities and Corresponding Scintillations Characterized Using a High‐Temporal‐Resolution GNSS Network

“…Nevertheless, owing to the dense coverage of GNSS measurements, ROTI was successfully used to characterize the morphology of large‐scale strong E s structures (e.g., Hosokawa et al., 2020; Saito et al., 2020), which can elongate up to ∼3,000 km (Sun et al., 2021). However, TEC disturbances caused by strong E s occurrences are usually short‐lived with durations of several minutes (e.g., Maeda & Heki, 2014; Sun, Wu, et al., 2020). For the traditionally used ROTI which are generally calculated at a 5‐min interval and the AATR index which is hourly weighted, they may not characterize the strong E s irregularities with a high temporal resolution.…”

Visualizing sporadic E using aeronautical navigation signals at VHF frequencies

“…The method of Maeda & Heki (2014, 2015 picks up pulse-like increases in the slant TEC time-series as crosssections of strong Es front. Since such a spiky variation mostly continues only for a few min (e.g., Maeda & Heki, 2014;Sun et al, 2020), the current mapping method using ROTI might not be able to detect the sharp TEC pulses due to the relatively low temporal resolution (5 min). This may mean that the width of frontal Es structures can be overestimated in the ROTI map.…”