Some climate alarmists
claim that man-made
climate change
is causing Arctic air
to be displaced south.
The claim is that
man-made global
warming affects
the polar jet stream
-- meaning that
without global warming,
polar air would stay
near the north pole.
NOT TRUE !
The polar vortex
surrounds the
coldest air above
the North Pole.
The Northern
Hemisphere
polar vortex
is not unusual,
extreme, or
something new.
The tropospheric
polar vortex is between
5,000 feet (850 mb)
and 52,000 feet (100 mb).
A stratospheric
polar vortex
is located
much farther up.
The tropospheric
polar vortex
circulation
is much large
than the
stratospheric
circulation.
The tropospheric
polar vortex
is present
all year long.
The stratospheric
vortex is only present
during the late autumn,
winter, and early spring.
Greenhouse gas
warming theory,
and experience,
shows us the Arctic
is warming faster
at low and mid-levels
of the atmosphere,
compared to
anywhere else.
A warming Arctic
reduces the
temperature
difference
(gradient)
between the
Arctic and
the tropics.
The gradient
between the
tropical and
Arctic tropospheric
temperatures
HAS been reduced.
The reduced
temperature
gradient between
the Arctic and
the tropics
results in a
WEAKER
jet stream.
Note: During
summer months,
the polar jet stream
is weaker, which is
why we rarely have
cool air outbreaks
during the summer.
Very cold
air outbreaks
occur every year
in the historical
temperature sata.
Cold spells
in the U.S.
have actually
become less
common over
the last 124 years.
Raw temperature
data from the
United States
Historical
Climatology
Network
(USHCN)
was examined by
Climatologist,
Dr. John Christy.
The average number
of November through
March cold waves,
lasting at least two days,
in 27 Midwestern,
Mid-Atlantic, and
New England states,
has decreased from
around five times
per year in the 1890s
and 1900s, to around
three times per year
in the last decade.
If global warming
really caused MORE
cold waves coming
south from the Arctic ,
then why are there
FEWER cold waves
coming south
from the Arctic ?