Connections between the non-migrating semidiurnal tide over the South Pole and stationary planetary waves in the northern hemisphere.

摘要

The westward propagating zonal wavenumber 1 non-migrating semidiurnal tide is a dominant dynamical feature present during the Austral summer over the South Pole. It has been hypothesized that this wave is generated by a non-linear interaction between the zonal wavenumber one stationary planetary wave in the northern hemisphere stratosphere and the zonal wavenumber two migrating diurnal tide. However, direct evidence of this interaction has yet to be observed.;Using observations from the South Pole meteor radar (SPMR) system we can unambiguously determine the structure of the non-migrating semidiurnal tide in the meridional wind field. These observations are correlated with the stationary planetary wave activity in the zonal and meridional wind fields in the northern hemisphere stratosphere. Data from the NASA Modern Era Retrospective-Analysis for Research and Applications (MERRA) global assimilative model are used to determine the structure of the zonal wavenumber 1,2, and 3 stationary planetary waves for this comparison.;In addition, temperature data from the NASA TIMED SABER mission was analyzed and compared to the MERRA temperature observations as validation of the MERRA model results. Correlation analysis has indicated periods of time with significant correlation between the zonal wavenumber 1 stationary planetary wave and the SPMR data and other times with very strong anti-correlations. Similar features are observed with the zonal wavenumber 3 stationary planetary wave.