French, W.J.R. and Mulligan, F.J.
Stability of temperatures from TIMED/SABER v1.07 (2002–2009)
and Aura/MLS v2.2 (2004–2009) compared with OH(6-2)
temperatures observed at Davis Station, Antarctica.
Atmospheric Chemistry and Physics, 10.
Temperature profiles from two satellite instruments
– TIMED/SABER and Aura/MLS – have been used
to calculate hydroxyl-layer equivalent temperatures for comparison
with values measured from OH(6-2) emission lines
observed by a ground-based spectrometer located at Davis
Station, Antarctica (68 S, 78 E). The profile selection criteria
– miss-distance <500 km from the ground station and
solar zenith angles >97 – yielded a total of 2359 SABER
profiles over 8 years (2002–2009) and 7407 MLS profiles
over 5.5 years (2004–2009). The availability of simultaneous
OH volume emission rate (VER) profiles from the SABER
(OH-B channel) enabled an assessment of the impact of several
different weighting functions in the calculation of OHequivalent
temperatures. The maximum difference between
all derived hydroxyl layer equivalent temperatures was less
than 3 K. Restricting the miss-distance and miss-time criteria
showed little effect on the bias, suggesting that the OH layer
is relatively uniform over the spatial and temporal scales considered.
However, a significant trend was found in the bias
between SABER and Davis OH of 0.7 K/year over the 8-
year period with SABER becoming warmer compared with
the Davis OH temperatures. In contrast, Aura/MLS exhibited
a cold bias of 9.9±0.4K compared with Davis OH,
but importantly, the bias remained constant over the 2004–
2009 year period examined. The difference in bias behaviour
of the two satellites has significant implications for multiannual
and long-term studies using their data.
||© Author(s) 2010. Creative Commons Attribution 3.0 License. Acknowledgements: The authors gratefully acknowledge the assistance
of the Optical Physicists at Davis in collecting the hydroxyl
airglow data. This work is supported by the Australian Antarctic
science advisory committee. We thank the TIMED/SABER and
Aura/MLS science teams for providing data used in this study. We
also kindly thank two anonymous referees for insightful comment
and helpful suggestions on this manuscript.
||Stability; temperatures; TIMED/SABER; Aura/MLS; OH(6-2)
temperatures; Davis Station; Antarctica;
||Science & Engineering > Experimental Physics
Dr. Frank Mulligan
||08 Sep 2011 08:15
|Journal or Publication Title:
||Atmospheric Chemistry and Physics
||Copernicus Publications for European Geosciences Union (EGU)
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