| This study uses observations from the EOS-MLS satellite instrument to demonstrate that
variations in the temperature and altitude of the stratopause display inter-hemispheric
linkages. In particular, variations in the stratopause altitude and temperature inside the polar
vortices can often be linked to anti-correlated variations in the tropics. We focus on strong
variations in the Southern hemisphere polar vortex in 2010 which caused significant changes
in the stratopause properties all the way into the Northern hemisphere tropics. In previous
studies of inter-hemispheric coupling, the focus has generally been on variations in the
Northern hemisphere stratosphere affecting the Southern hemisphere. The observed patterns
are then further analysed in an attempt to discern whether this pattern is a reflection of the
previously observed stratosphere-mesosphere linkage or a separate phenomenon.
We then use the information derived from the MLS data, along with additional
ancillary reanalyses and COSMIC data, to gain some understanding of the conditions
required in the middle atmosphere for these patterns to occur. We also examine the
planetary and gravity wave fields in the stratosphere using both MLS and COSMIC to
attempt to understand whether atmospheric waves play a significant role in the
propagation of these signals from one hemisphere to the other. We also examine whether
the changes observed have any impact on the vertical propagation of these waves. |