Planetary waves in the winter mesosphere ‐ preliminary analysis of nimbus 6 PMR results

• Published in: Quarterly Journal of the Royal Meteorological Society
• Main Authors: Hirota, I., Barnett, J. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1977
• Subjects: polar night
• Online Access: http://dx.doi.org/10.1002/qj.49710343709; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.49710343709; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.49710343709

Abstract The temperature field of the northern hemisphere mesosphere during the mid‐winter of 1975/1976 is described by the use of radiance observations made by the Pressure Modulator Radiometer (PMR) on the Nimbus 6 satellite. A month's average of the radiance field indicates that planetary waves of wavenumbers one and two are of significant amplitude in the winter hemisphere up to the highest level observed by the PMR (∼85 km). These waves show a westward tilt of wave axis with height, and the maximum amplitude is observed in the middle mesosphere to the north of the polar‐night westerly jet. Time series analysis of the zonal mean radiance during the period of a minor stratospheric warming in early 1976 indicates that the stratospheric and lower mesospheric temperature increases with time in the higher latitudes to the north of 30°N, associated with the amplification of wavenumber one, while the upper mesospheric temperature decreases with time at all latitudes. A rough estimate is also given of the time change of the mid‐latitude mean zonal wind during the period of the warming.