A 20-day period standing oscillation in the northern winter stratosphere
Observations of the ozone profile by a ground-based microwave radiometer in Switzerland indicate a dominant 20-day oscillation in stratospheric ozone, possibly related to oscillations of the polar vortex edge during winter. For further understanding of the nature of the 20-day oscillation, the o...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-04-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/31/755/2013/angeo-31-755-2013.pdf |
| Summary: | Observations of the ozone profile by a ground-based microwave
radiometer in Switzerland indicate a dominant 20-day oscillation in
stratospheric ozone, possibly related to oscillations of the polar vortex
edge during winter. For further understanding of the nature of the 20-day
oscillation, the ozone data set of ERA Interim meteorological reanalysis is
analyzed at the latitude belt of 47.5° N and in the time from 1979 to
2010. Spectral analysis of ozone time series at 7 hPa indicates that the
20-day oscillation is maximal at two locations: 7.5° E,
47.5° N and 60° E, 47.5° N. Composites of the stream
function are derived for different phases of the 20-day oscillation of
stratospheric ozone at 7 hPa in the Northern Hemisphere. The streamline at
Ψ = −2 × 10<sup>7</sup> m<sup>2</sup> s<sup>−1</sup> is in the vicinity of the polar vortex
edge. The other streamline at Ψ = 4 × 10<sup>7</sup> m<sup>2</sup> s<sup>1</sup> surrounds the
Aleutian anticyclone and goes to the subtropics. The composites show 20-day
period standing oscillations at the polar vortex edge and in the subtropics
above Northern Africa, India, and China. The 20-day period standing
oscillation above Aral Sea and India is correlated to the strength of the
Aleutian anticyclone. |
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| ISSN: | 0992-7689 1432-0576 |