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Abstract This paper investigates the midlatitude ionospheric disturbances over the American/Atlantic longitude sector during an intense geomagnetic storm on 23 April 2023. The study utilized a combination of ground‐based observations (Global Navigation Satellite System total electron content and ionosonde) along with measurements from multiple satellite missions (GOLD, Swarm, Defense Meteorological Satellite Program, and TIMED/GUVI) to analyze storm‐time electrodynamics and neutral dynamics. We found that the storm main phase was characterized by distinct midlatitude ionospheric density gradient structures as follows: (a) In the European‐Atlantic longitude sector, a significant midlatitude bubble‐like ionospheric super‐depletion structure (BLISS) was observed after sunset. This BLISS appeared as a low‐density channel extending poleward/westward and reached ∼40° geomagnetic latitude, corresponding to an APEX height of ∼5,000 km. (b) Coincident with the BLISS, a dynamic storm‐enhanced density plume rapidly formed and decayed at local afternoon in the North American sector, with the plume intensity being doubled and halved in just a few hours. (c) The simultaneous occurrence of these strong yet opposite midlatitude gradient structures could be mainly attributed to common key drivers of prompt penetration electric fields and subauroral polarization stream electric fields. This shed light on the important role of storm‐time electrodynamic processes in shaping global ionospheric disturbances.
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New Index to Characterize Ionospheric Irregularity Distribution
Abstract Characterization of the global ionospheric irregularities as a function of local time, longitude, altitude, and magnetic activities is still a challenge for radio frequency operations, especially at the low‐latitude region. One of the main reasons is lack of observations due to the unevenly distributed instruments. To overcome this constraint, we developed a new spatial density gradient index (DGRI) at two different scale sizes: small scale and medium/large scale. The DGRI is derived from in situ density measurements onboard recently launched constellation of low‐Earth‐orbiting satellites (COSMIC‐2 and ICON) at the rate of 1 Hz. Hence, the DGRI appeared to be suitable parameter that can be used as a proxy to describe the essential features of ionospheric disturbances that may critically affect our radio wave application as well as to identify the “all clear” zone as a function of longitude, latitude, and local time—at a refreshment rate of 30 min or less.
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- Award ID(s):
- 1848730
- PAR ID:
- 10465486
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Space Weather
- Volume:
- 21
- Issue:
- 9
- ISSN:
- 1542-7390
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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