The second reason : Polar Vortex
A polar vortex is a persistent, large-scale cyclone located near either of a planet's geographical poles. On Earth, the polar vortices are located in the middle and upper troposphere and the stratosphere. They surround the polar highs and lie in the wake of the polar front. These cold-core low-pressure areas strengthen in the winter and weaken in the summer due to their reliance upon the temperature differential between the equator and the poles. They usually span less than 1,000 kilometers (620 miles) in which the air circulates in a counter-clockwise fashion (in the Northern Hemisphere). As with other cyclones, their rotation is caused by the Coriolis effect movement.
Atmospheric effects of polar vortex
For the Unisonal Vortex Mechanism perspective, the cold core phenomenon of polar vortex from mid to top section of stratosphere is as a result of sunken mesosphere has filled the void in the vortex column. And the polar climate is largely as a result of a polar vortex has vertically dispersed troposphere in the nested vortex column, with the freezing tropopause lowered to around the ground level.
UVS qualitatively predicts that polar climate is significantly caused by vertically dispersed atmospheric layers in the vortex column of a polar vortex.
For the UVS perspective, the polar vortex of stratosphere with its vortex column manifested within the boundary of the subtropical jet stream is the causality for the subtropical climate.
UVS qualitatively predicts subtropical climate is primarily caused by the polar vortex of stratosphere with its vortex column manifested within the boundary of the subtropical jet stream.
With lesser dragging effect of landmass at the South Pole, the Antarctica polar vortex would be more intensified than the Arctic polar vortex for lowering and displacing the troposphere with freezing tropopause layer in its vortex column, with its high altitude continent, and also the polar vortex is most intensified by a perigee Moon during lunar oppositions in winter night that causes its vortex column in troposphere to widely open, could rationally explain why Antarctica is the coldest place on Earth.
Atmospheric effects of polar vortex
For the Unisonal Vortex Mechanism perspective, the cold core phenomenon of polar vortex from mid to top section of stratosphere is as a result of sunken mesosphere has filled the void in the vortex column. And the polar climate is largely as a result of a polar vortex has vertically dispersed troposphere in the nested vortex column, with the freezing tropopause lowered to around the ground level.
UVS qualitatively predicts that polar climate is significantly caused by vertically dispersed atmospheric layers in the vortex column of a polar vortex.
For the UVS perspective, the polar vortex of stratosphere with its vortex column manifested within the boundary of the subtropical jet stream is the causality for the subtropical climate.
UVS qualitatively predicts subtropical climate is primarily caused by the polar vortex of stratosphere with its vortex column manifested within the boundary of the subtropical jet stream.
With lesser dragging effect of landmass at the South Pole, the Antarctica polar vortex would be more intensified than the Arctic polar vortex for lowering and displacing the troposphere with freezing tropopause layer in its vortex column, with its high altitude continent, and also the polar vortex is most intensified by a perigee Moon during lunar oppositions in winter night that causes its vortex column in troposphere to widely open, could rationally explain why Antarctica is the coldest place on Earth.
Earth's atmosphere chart showing its temperature distribution
From the UVS perspective, a polar vortex column of troposphere widened by precession effect can cause polar climate to extend nearer to the equator. Precession is a change in the orientation of the rotational axis of a rotating body.
Orientation and position of the Polar Vortex in 2013-2014 Winter Hemisphere
From the UVS perspective, a polar vortex column of troposphere widened by precession effect can cause polar climate to extend nearer to the equator. Precession is a change in the orientation of the rotational axis of a rotating body.
Orientation and position of the Polar Vortex in 2013-2014 Winter Hemisphere
The typical polar vortex configuration in November, 2013...
...A wavy polar vortex on January 5,
2014.
On December 1, 2013, the weakening of the polar vortex led to the beginning of an abnormally cold trend in the Eastern and Central United States. On December 6, the continued deterioration of the polar vortex led to the jet stream pushing southward, bringing record cold temperatures across the Eastern United States of America, from December 6 to December 10, when the arctic air retreated from the region.
Beginning on January 2, 2014, sudden stratospheric warming (SSW) led to the breakdown of the regular polar vortex and subsequent southward movement of tropospheric Arctic air.
On December 1, 2013, the weakening of the polar vortex led to the beginning of an abnormally cold trend in the Eastern and Central United States. On December 6, the continued deterioration of the polar vortex led to the jet stream pushing southward, bringing record cold temperatures across the Eastern United States of America, from December 6 to December 10, when the arctic air retreated from the region.
Beginning on January 2, 2014, sudden stratospheric warming (SSW) led to the breakdown of the regular polar vortex and subsequent southward movement of tropospheric Arctic air.