Multitaper analysis of an MSTID event above Antarctica on 17 March 2013

• Published in: Polar Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Multitaper; MSTID; SuperDARN; SANAE; Antarc*; Antarctica; Polar Science
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16476; http://id.nii.ac.jp/1291/00016349/

A medium-scale travelling ionospheric disturbance (MSTID) was observed concomitantly by SANAE and Halley SuperDARN HF radars during the period 02–06 UT 17 March 2013. The event occurred during a geomagnetically quiet time where no substorm or storm activities were observed. Both radars (at similar geomagnetic latitudes of 61.80S (SANAE) and 62.10S (Halley)) are well placed for observing the sporadic E (Es) region associated with the ionospheric trough around midnight during quiet geomagnetic conditions. F region electrodynamics and electrical coupling between E and F regions are one of the important mechanisms for the generation of nighttime MSTIDs. This is thought to be the generation mechanism in this study. We analysed the radar data using multitaper method (MTM). Multiple windowing mitigates spectral leakage and bias. The orthogonality of the tapers allows for confidence levels of peaks to be determined. The results from both radars show an MSTID with a period of approximately 23 min propagating at a speed ~280 ms−1 (SANAE) and 178 ms−1 (Halley) in the Southeast direction. An upper limit of ~55 kW was estimated to be dissipated by Joule heating due to the MSTID over an area where it was detected by both radars with more than 90% confidence.