Abstract. During minor to moderate geomagnetic storms, caused by corotatinginteraction regions (CIRs) at the leading edge of high-speed streams (HSSs), solar windAlfvén waves modulated the magnetic reconnection at the daysidemagnetopause. The Resolute Bay Incoherent Scatter Radars (RISR-C andRISR-N), measuring plasma parameters in the cusp and polar cap, observedionospheric signatures of flux transfer events (FTEs) that resulted in theformation of polar cap patches. The patches were observed as they moved over the RISR, and the Canadian High-Arctic Ionospheric Network (CHAIN)ionosondes and GPS receivers. The coupling process modulated the ionospheric convection and the intensity of ionospheric currents, including the auroral electrojets. The horizontal equivalent ionospheric currents (EICs) are estimated from ground-based magnetometer data using an inversion technique. Pulses of ionospheric currents that are a source of Joule heating in the lower thermosphere launched atmospheric gravity waves, causing travelingionospheric disturbances (TIDs) that propagated equatorward. The TIDs wereobserved in the SuperDual Auroral Radar Network (SuperDARN) high-frequency (HF) radar groundscatter and the detrended total electron content (TEC) measured by globallydistributed Global Navigation Satellite System (GNSS) receivers.
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Using Data Assimilation to Reconstruct High‐Latitude Polar Cap Patches
Discrete high‐density plasma structures in the Earth's ionosphere that convect across the polar cap from the dayside to nightside are known as polar cap patches. This high‐latitude phenomenon can interfere and disrupt satellite and high‐frequency (HF) communications when the associated sharp electron density gradients are encountered, and therefore, accurate modeling and forecasting of such events would be greatly beneficial. In this study, we have utilized the assimilative Global Positioning System Ionospheric Inversion (GPSII) method to reconstruct the high‐latitude ionosphere utilizing data from Global Navigation Satellite System (GNSS) receivers, vertical ionosondes, the Resolute Bay Incoherent Scatter Radar (RISR‐N), in situ satellite data, and Super Dual Auroral Radar Network (SuperDARN) radars. The novel method of assimilating RISR‐N and SuperDARN ground scatter measurements helps to increase the limited number of observations at high latitudes. The reconstructed polar cap patches are shown to correspond with ground‐ and spaced‐based observations, illustrating the ability of utilizing GPSII to study the complex high‐latitude region.
more » « less- NSF-PAR ID:
- 10452705
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Radio Science
- Volume:
- 55
- Issue:
- 6
- ISSN:
- 0048-6604
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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