What is Polar Vortex?
In the winter, after November, the cold starts to increase in the upper latitudes
because the angle between the sun and the earth has changed.
The north hemisphere pole cools.
There is a vortex that holds the polar cold.
The vortex surrounds the cold and keeps it there.
What is polar vortex to this vortex.
Another definition of Polar vortex
In the polar regions, cold air collapses,
the heated air rises and the pressure field is formed.This pressure field is called polar vortex.
now
There are stratospheric and tropospheric polar vortex.
I am studying polar vortex in the stratosphere(30-50km).
Here, polar vortex winds run west and east.
If it is blowing counterclockwise, the west
is blowing clockwise, and if it is clockwise,
it works in the east direction.
We were just talking about the vortex.
You can compare it with the winds.
Polar vortex winds are studied in the stratosphere
and affect countries in the southern latitudes.
How does it affect?
With the anticyclone set in the northern hemisphere
pole, vortex cold spreads towards the lower latitudes.
Polar vortex winds are strong in the west
direction.
Polar vortex is strong and surrounds the cold better.
It prevents the arctic colds from spreading(lower latitudes)
in lower latitudes.(Europe, Asia, Turkey,
USA)
If polar vortex winds are weak, the cold will spread to the
southern latitudes.
Because the vortex surrounding the polar cold weakens.
So how is the state of the vortex evaluated?
There is the value of polar vortex at 60 degrees latitude.
If values above 0 m / s are observed, the
polar vortex in the west direction.Polar vortex is strong
If values below 0 m / s are observed, the
polar vortex is weak.
Our reference value is 0m / s.
If the vortex is weak, a cold outbreak may
occur in the lower latitudes.
If it is strong polar vortex, the cold outbreak
rarely occurs in the lower latitudes, the
polar region cools and the amount of ice increases.
Polar vortex information can be obtained from NASA.
There is an average wind graph of 60 degrees north latitude.
There are numerical values in the vertical
part of the graph, and days in the horizontal
part.
If the graphic line is below 0 m / s, there
may be a cold outbreak in the lower latitudes.
Winds that turn east in weak polar vortex
appear with sudden stratospheric warming.
Look, this is very important.
If the polar vortex weakens, the stratosphere
becomes hot.
Where does this warming take place?
It occurs on Eurasia and Canada.
It takes place in two regions.
There are two types of stratosphere warming.
These two types of polar vortex give different responses.
The first reaction is "displacement"
The polar vortex shifts.
The winds are weakened but not below 0 m / s.They're just weak.
The second response is "split".
In the polar vortex split event, the winds
fall below 0m / s.
This is the explanation in the general literature.
In the event of splitting, which occurs as
a result of sudden stratosphere warming, the winds run east.
Winds blowing west or east are modulated by
polar vortex splitting and displacement events.
The values here are taken into consideration
between November and April.
In summer, stratospheric polar vortex is not
observed.
If you want to make a forecast in the winter
season, it will be sufficient to look at the
polar vortex graph(stratospheric and tropospheric vortex).
That's it for Polar vortex.
Sudden Stratoshperic Warming example event
Thanks for watching.
