Arctic and Antarctic polar mesosphere summer echoes observed with oblique incidence HF radars: analysis using simultaneous MF and VHF radar data

Polar mesosphere summer echoes (PMSEs) have been well studied using vertical incidence VHF radars at northern high-latitudes. In this paper, two PMSE events detected with the oblique incidence SuperDARN HF radars at Hankasalmi, Finland (62.3° N) and Syowa Station, Antarctica (69.0° S), are analyzed,...

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Bibliographic Details
Published in:Annales Geophysicae
Main Authors: Ogawa, T., Nozawa, S., Tsutsumi, M., Arnold, N. F., Nishitani, N., Sato, N., Yukimatu, A. S.
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2004
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Online Access:https://doi.org/10.5194/angeo-22-4049-2004
https://noa.gwlb.de/receive/cop_mods_00034493
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00034447/angeo-22-4049-2004.pdf
https://angeo.copernicus.org/articles/22/4049/2004/angeo-22-4049-2004.pdf
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Summary:Polar mesosphere summer echoes (PMSEs) have been well studied using vertical incidence VHF radars at northern high-latitudes. In this paper, two PMSE events detected with the oblique incidence SuperDARN HF radars at Hankasalmi, Finland (62.3° N) and Syowa Station, Antarctica (69.0° S), are analyzed, together with simultaneous VHF and medium-frequency (MF) radar data. Altitude resolutions of the HF radars in the mesosphere and the lower thermosphere are too poor to know exact PMSE altitudes. However, a comparison of Doppler velocity from the HF radar and neutral wind velocity from the MF radar shows that PMSEs at the HF band appeared at altitudes within 80-90km, which are consistent with those from previous vertical incidence HF-VHF radar results. The HF-VHF PMSE occurrences exhibit a semidiurnal behavior, as observed by other researchers. It is found that in one event, PMSEs occurred when westward semidiurnal winds with large amplitude at 85-88km altitudes attained a maximum. When the HF-VHF PMSEs were observed at distances beyond 180km from MF radar sites, the MF radars detected no appreciable signatures of echo enhancement. Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides)