Southern Hemisphere Planetary-scale Waves and Blocking

Planetary and Synoptic Scale Interactions in Southeast Pacific Blocking Using Potential Vorticity Diagnostics: More Evidence for the Paucity of Wave- Wave Interactions in Southern Hemisphere Blocking

Climatological studies of blocking in the Southern Hemisphere (SH) demonstrate that blocking events are less common (e.g. Lejenas, 1984; Renwick 1998), and are weaker (e.g. Wiedenmann, et al., 2002; hereafter WLMT02) throughout the SH when compared to their NH counterparts. WLMT02 implied that the relative roles in the interaction between planetary-scale and synoptic-scale waves may partially e...

Impact of Tropical SST on Stratospheric Planetary Waves in the Southern Hemisphere

The impact of tropical sea surface temperature (SST) on stratospheric planetary waves in the Southern Hemisphere (SH) is investigated in austral spring using observed SST and reanalysis data for the past three decades. Maximum covariance analysis indicates that the tropical SST and the SH stratospheric planetary wave activity are primarily coupled through two modes. The leading two modes show t...

Impact of tropical sea surface temperatures on 1 Southern Hemisphere stratospheric planetary 2 waves

Error growth and dynamical vectors during southern hemisphere blocking

The structural organization of initially random perturbations or “errors” evolving in a barotropic tangent linear model with time-dependent basic states taken from observations, is examined for cases of block development, maturation and decay in the Southern Hemisphere atmosphere during April, November and December 1989. We determine statistical results relating the structures of evolved errors...

Periodic variability in the large-scale Southern Hemisphere atmospheric circulation.

Periodic behavior in the climate system has important implications not only for weather prediction but also for understanding and interpreting the physical processes that drive climate variability. Here we demonstrate that the large-scale Southern Hemisphere atmospheric circulation exhibits marked periodicity on time scales of approximately 20 to 30 days. The periodicity is tied to the Southern...