Comparison of D-region Doppler drift winds measured by the SuperDARN Finland HF radar over an annual cycle using the Kiruna VHF meteor radar

• Published in: Annales Geophysicae
• Main Authors: Arnold, N. F., Cook, P. A., Robinson, T. R., Lester, M., Chapman, P. J., Mitchell, N.
• Format: Article in Journal/Newspaper
• Language: English
• Published: European Geosciences Union (EGU), Copernicus Publications, Springer Verlag (Germany) 2017
• Subjects: Science & Technology; Physical Sciences; Astronomy & Astrophysics; Geosciences; Multidisciplinary; Meteorology & Atmospheric Sciences; Geology; ionosphere; ionosphere-atmosphere interactions; instruments and techniques; meteorology and atmospheric dynamics; waves and tides; NETWORK OBSERVATIONS; UPPER-ATMOSPHERE; DECAY TIMES; ECHOES; Kiruna; Iceland
• Online Access: http://www.ann-geophys.net/21/2073/2003/angeo-21-2073-2003.html; http://hdl.handle.net/2381/39443; https://doi.org/10.5194/angeo-21-2073-2003

The SuperDARN chain of oblique HF radars has provided an opportunity to generate a unique climatology of horizontal winds near the mesopause at a number of high latitude locations, via the Doppler shifted echoes from sources of ionisation in the D-region. Ablating meteor trails form the bulk of these targets, but other phenomena also contribute to the observations. Due to the poor vertical resolution of the radars, care must be taken to reduce possible biases from sporadic-E layers and Polar Mesospheric Summer echoes that can affect the effective altitude of the geophysical parameters being observed. Second, there is strong theoretical and observational evidence to suggest that the radars are picking up echoes from the backward looking direction that will tend to reduce the measured wind strengths. The effect is strongly frequency dependent, resulting in a 20% reduction at 12 MHz and a 50% reduction at 10 MHz. A comparison of the climatologies observed by the Super-DARN Finland radar between September 1999 and September 2000 and that obtained from the adjacent VHF meteor radar located at Kiruna is also presented. The agreement between the two instruments was very good. Extending the analysis to the SuperDARN Iceland East radar indicated that the principles outlined above could be applied successfully to the rest of the SuperDARN network. The authors wish to thank the team at the Radio and Space Plasma Physics group who constructed, deployed and operated the CUTLASS HF radars over the past five years. We are grateful for the constructive comments of one of the referees. N. F. Arnold was supported by an advanced fellowship from the UK Particle Physics and Astronomy Research Council, P.A. Cook by PPARC grant RP16017 and CUTLASS operations were supported by PPARC grant RP16021. Peer-reviewed Publisher Version