Dyrland, M.E. and Mulligan, F.J. and Hall, C.M. and Sigernes, F. and Tsutsumi, M. and Deehr, C.S.
Response of OH airglow temperatures to neutral air dynamics
at 78oN, 16oE during the anomalous 2003-2004 winter.
Journal of Geophysical Research, 115 (D7).
Hydroxyl (OH) brightness temperatures from the mesopause region derived from
temperature profiles from the Sounding of the Atmosphere using Broadband Emission
Radiometry (SABER) instrument on the Thermosphere, Ionosphere, Mesosphere
Energetics and Dynamics (TIMED) satellite are compared with OH(6-2) rotational
temperatures measured by spectrometer from Longyearbyen, Norway (780N, 16"E),
during the winter 2003-2004. The two series correspond well, although the satellite
measurements are higher by an average of 5.6 K * 4.4 K. Reasons for this apparent bias are
discussed. The two series give a near-continuous temperature record from this winter,
making it possible to study the response of the temperatures to neutral air dynamics
observed from meteor radar measurements of meridional and zonal wind. Vertical profiles
of 1.6 pm OH volume emission rates from SABER reveal that the unusually high
temperatures observed during January and February 2004 (240-250 K) correspond to a
very low and bright OH layer. Significant linear correlations are found between meridional
wind, OH temperature, and peak altitude. These data support the theory that the high
temperatures result from an anomalously strong upper stratospheric vortex that confined
air to the polar regions, coupled with meridional transport, which led to a strong
downwelling of atomic oxygen-rich air, thereby lowering the altitude of the OH layer. The
SABER data reveal that the re-formation of the OH layer at approximately 78 km altitude
accounted for an increase in temperature of approximately 15 K, while the remaining
temperature increase (20-35 K) is attributed to adiabatic heating and chemical heating
from the exothermic reactions involved in producing the vibrationally excited OH.
||An edited version of this paper was published by AGU. Copyright (2010) American Geophysical Union. Acknowledgments: We are very grateful to the entire NASA TlMED/SABER team for making the SABER data freely avaiIable. We also thank the three anonymous reviewers for their constructive comments and suggestions, which helped improve the paper.
||Atmospheric Processes; Middle atmosphere dynamics (0341, 0342); Atmospheric Composition and Structure; Airglow and aurora; Atmospheric Processes; Climate change and variability (1616, 1635, 3309, 4215, 4513); Planetary Sciences; Solid Surface Planets; Polar regions;
||Faculty of Science and Engineering > Experimental Physics
Dr. Frank Mulligan
||08 Sep 2011 08:16
|Journal or Publication Title:
||Journal of Geophysical Research
||American Geophysical Union (AGU)
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