Polar vortex evolution during Northern Hemispheric winter 2004/05

As a part of the project "Atmospheric Wave Influences upon the Winter Polar Vortices (0–100 km)" of the CAWSES program, data from meteor and Medium Frequency radars at 12 locations and MetO (UK Meteorological Office) global assimilated fields have been analyzed for the first campaign durin...

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Bibliographic Details
Published in:Annales geophysicae (1988) 2007-01, Vol.25 (6), p.1279-1298
Main Authors: Chshyolkova, T., Manson, A. H., Meek, C. E., Aso, T., Avery, S. K., Hall, C. M., Hocking, W., Igarashi, K., Jacobi, C., Makarov, N., Mitchell, N., Murayama, Y., Singer, W., Thorsen, D., Tsutsumi, M.
Format: Article
Language:English
Subjects:
Atmospheric circulation
Earth Sciences
Geofag: 450
Geosciences: 450
Matematikk og Naturvitenskap: 400
Mathematics and natural science: 400
Meteorologi: 453
Meteorology: 453
Middle atmosphere
Ocean, Atmosphere
Polar vortex
Sciences of the Universe
VDP
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Summary:As a part of the project "Atmospheric Wave Influences upon the Winter Polar Vortices (0–100 km)" of the CAWSES program, data from meteor and Medium Frequency radars at 12 locations and MetO (UK Meteorological Office) global assimilated fields have been analyzed for the first campaign during the Northern Hemispheric winter of 2004/05. The stratospheric state has been described using the conventional zonal mean parameters as well as Q-diagnostic, which allows consideration of the longitudinal variability. The stratosphere was cold during winter of 2004/05, and the polar vortex was relatively strong during most of the winter with relatively weak disturbances occurring at the end of December and the end of January. For this winter the strongest deformation with the splitting of the polar vortex in the lower stratosphere was observed at the end of February. Here the results show strong latitudinal and longitudinal differences that are evident in the stratospheric and mesospheric data sets at different stations. Eastward winds are weaker and oscillations with planetary wave periods have smaller amplitudes at more poleward stations. Accordingly, the occurrence, time and magnitude of the observed reversal of the zonal mesospheric winds associated with stratospheric disturbances depend on the local stratospheric conditions. In general, compared to previous years, the winter of 2004/05 could be characterized by weak planetary wave activity at stratospheric and mesospheric heights.
ISSN:1432-0576
0992-7689
1432-0576
DOI:10.5194/angeo-25-1279-2007