scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

STP12 Abstracts
Berlin, 12 - 16 July 2010
SCOSTEP Symposium 2010
Activity of planetary waves at the stratosphere heights during 2007-2009 winters
Kanukhina Anna , Vlasov Alexey , Savenkova Elena , Pogoreltsev Alexandr
Russian State Hydrometeorological University
Planetary wave activity is studied in the boreal winter stratosphere on the basis of the UK Met
Office temperature and geopotential height data. Decomposition of standing and travelling
amplitudes according to the recalculation procedure produced the following results. During
2007-2009 winters, at the stratospheric higher-middle latitudes the amplitudes of eastward
traveling waves having period near 32 days dominate the westward ones according to analysis
of the temperature and geopotential height data. Amplitudes of the eastward travelling waves
at the 20 days period are comparable with the westward wave amplitudes or higher. Well
pronounced 5- and 7-10-day westward waves are characterized with maximal amplitudes.
While at the lower-middle latitudes the westward components of traveling planetary waves
are predominant both at the temperature and geopotential height data. The amplitudes of
stationary (standing) and traveling planetary waves are comparable in values within 30N-40N
area. It is obtained that, at 1 hPa height westward wave amplitudes are close to standing wave
amplitude values and having maxima within 7 and 22-day periods. UK Met Office data were
used to estimate intra-seasonal variability of the zonal mean planetary waves in the
stratosphere and allowed to clarify a dominance of eastward waves at higher latitudes than at
the lower ones. The described dominance of eastward waves within 60N-70N could be
explained with the coincidence to their generation area at the stratospheric heights. Another
line for a discussion is the amplification of stationary planetary waves during winters 2007-
2009 and their connection with the sudden stratospheric warming events.