A long-term comparison of wind and tide measurements in the upper mesosphere recorded with an imaging Doppler interferometer and SuperDARN radar at Halley, Antarctica R. E. Hibbins and M. J. Jarvis Physical Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
Abstract. Data from a near co-located imaging Doppler interferometer (IDI) and
SuperDARN radar recorded since 1996 have been analysed in a consistent
manner to compare the derived mean winds and tides in the upper mesosphere.
By comparing only days when both techniques were recording good quality
meridional wind data it is shown that the SuperDARN radar winds and tides
correlate best with the IDI height bin 90–95 km. On timescales of one hour
the winds derived from the IDI have a much greater associated variance and
correlate poorly with the SuperDARN winds. Regression analysis reveals that
the observed SuperDARN daily mean meridional wind strength is approximately
65% that recorded by the IDI, in good quantitative agreement with
previous studies which have shown contamination to SuperDARN derived winds
due to the significant back lobe of the radar radiation pattern.
Climatologically the two techniques observe similar monthly mean winds with
the SuperDARN meridional winds suppressed compared to the IDI which tends to
record winds more poleward than those derived by the SuperDARN radar during
the summer months, and to be slightly more equatorward during the winter.
The 12-h tidal amplitude and phase derived from both techniques are in good
agreement, whereas the 24-h tides are seen much more strongly in the
SuperDARN radar, especially in wintertime, with poor phase agreement. Long
term comparison of the two techniques reveals a tendency for the IDI
meridional winds to be more poleward during solar maximum especially during
summer time; an effect which is not reproduced in the meridional winds
derived from the SuperDARN radar. These results are discussed in the context
of previous studies to independently determine the veracity of each
technique, and to highlight the circumstances where data derived from these
two techniques can be used to draw reliable conclusions from comparative
studies based on geographically distributed pairs of instruments.
Citation: Hibbins, R. E. and Jarvis, M. J.: A long-term comparison of wind and tide measurements in the upper mesosphere recorded with an imaging Doppler interferometer and SuperDARN radar at Halley, Antarctica, Atmos. Chem. Phys., 8, 1367-1376, doi:10.5194/acp-8-1367-2008, 2008.