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| Titel |
Contribution of equatorial planetary waves to the temperature structure near the tropical tropopause |
| VerfasserIn |
K. M. Grise, D. W. J. Thompson |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250064315
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| Zusammenfassung |
| The seasonal cycle and variability of temperatures in the tropical lower stratosphere are commonly linked to the breaking of planetary-scale Rossby waves in the extratropical stratosphere. However, several studies have demonstrated that forcing from quasi-stationary equatorial planetary waves may also play a role. In this study, the authors examine COSMIC GPS radio occultation temperature profiles and ERA-Interim reanalysis data to diagnose the influence of the equatorial planetary waves on the temperature structure of the tropical lower stratosphere. In the long-term mean, equatorial planetary waves modulate tropical lower stratospheric temperatures up to an altitude of ~21 km. In contrast, variability in the equatorial planetary waves is linked to much shallower structures. For example, an enhancement of the climatological-mean pattern of equatorial planetary waves is associated with a sharp zonal-mean cooling within a narrow ~1 km layer near the tropical tropopause. Preliminary results indicate that the equatorial planetary waves may have a similar influence on the seasonal cycle of temperatures in this narrow layer. The results are contrasted to the temperature structures associated with variations in extratropical planetary wave forcing. |
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