Large-scale planetary disturbances in stratospheric temperature at high-latitudes in the southern summer hemisphere M. G. Shepherd1 and T. Tsuda2 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.