Sudden Stratospheric
Warming:
When the gravity waves break in the mean
wind and deposit their energy into the flow they can act to slow down
or even reverse the wind depending on the way the local gravity waves
are moving when they break.
This is exactly what happens when there is a sudden
stratospheric
warming. The gravity waves break in the winds of the polar vortex
and slow down the eastward winds.
We remember that when the cold air decends it's energy is converted
into eastward winds by the corriolis effect. However, if these winds
are blocked the decending air compresses and heats very rapidly. This heating can
happen on the order of hours or days and be tens of Kelvins in
magnitude.
