Large-scale planetary disturbances in stratospheric temperature at high-latitudes in the southern summer hemisphere
1Centre for Research in Earth and Space Science, York University, Toronto, Canada
2Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, Japan
Abstract. The global structure and propagation of large-scale (periods >5 days) waves in the Southern Hemisphere summer (December 2006–February 2007) at 60° S–75° S latitude are examined using temperature data from GPS radio occultation measurements by COSMIC/FORMOSAT 3 satellite constellation at 20 km and 30 km altitude. Spectral analysis has revealed eastward propagating planetary scale perturbations with wavenumbers 1 and 2 and periods of 10, 16 and 23 days, and stationary waves with wavenumbers 1 and 2. The results obtained show a very dynamically active Antarctic summer stratosphere. The novel aspect of the work is in the use of the GPS COSMIC data providing multiple local times each day, thus allowing large-scale wave analysis at high Southern latitudes and revealing planetary wave activity not normally observed in summer, but more consistent with late winter and spring conditions in the stratosphere.
Citation: Shepherd, M. G. and Tsuda, T.: Large-scale planetary disturbances in stratospheric temperature at high-latitudes in the southern summer hemisphere, Atmos. Chem. Phys., 8, 7557-7570, doi:10.5194/acp-8-7557-2008, 2008.