The polar vortex that will determine the fate of the Earth
The north and south poles of the Earth are two enigmatic places full of great mysteries;
in these areas of the planet, there are meteorological phenomena that do
not occur anywhere else, and although it sounds like a conspiracy theory or
science fiction movie, at the poles of the Earth there are two huge, icy menace walls
that protect us from an ice threat that has claimed many lives throughout human history.
But don't worry, before you start imagining huge walls of ice and giant creatures that
threaten the human race, you should know that we are not talking about a wall of ice
but rather an invisible wall of air, and by threats, we don't mean referring to creatures
but incredible atmospheric phenomena. Do you want to know what this invisible
wall is and what atmospheric phenomena we are discussing? Join us to find out!
The threat of ice, the polar vortex The threat that we talked about at the beginning
of this video is an atmospheric phenomenon called "Polar Vortex, "this is a large-scale
persistent cyclone that is located in the polar areas of the Earth, and it is one of the most
terrifying, must be treated with respect because throughout history they have claimed many lives.
There are two polar vortices, one in the north and one in the south.
The Antarctic polar vortex is more pronounced and persistent than the Arctic vortex; This is because
the distribution of land masses in high latitudes in the Northern Hemisphere leads to an increase in
Rossby waves that help break the vortex and cause it to move out of the regions where it is normally
found. In contrast, the vortex remains less affected in the southern hemisphere because it
is concentrated almost entirely over Antarctica. Rossby atmospheric waves are produced by the
conservation of vortex power and are influenced by the Coriolis force and the pressure gradient.
Earth's rotation causes fluids like the atmosphere to rotate to the right as they move
in the Northern Hemisphere and to the left in the Southern Hemisphere, this is the Coriolis force.
For example, a fluid moving from the equator toward the north pole will be diverted to the
east; a fluid moving toward the equator from the north will be diverted to the west. This is one
of the reasons hurricanes occur and why hurricanes spin in different directions depending on whether
they originate from the north or the south. Polar vortices are weakest during the summer
and strongest during the winter. Extratropical cyclones migrating
to higher latitudes when the polar vortex is weak can disrupt the single vortex by creating
smaller vortices within the polar air mass. Each polar vortex is divided into two main parts;
the tropospheric polar vortex, which is at an altitude of 10 to 15 km, and the stratospheric
polar vortex, which is above 50 km. The two polar vortices are permanently
rotating in the same direction as the Earth's rotation, and the winds can reach speeds of up
to 240 km/h. Consider that winds from 120 km/h are already considered hurricanes.
This is truly impressive, don't you think? But the real question to ask ourselves is…
How can these cyclones exist at the Earth's poles? Why do they never stop?
And the answer to those questions is straightforward: The temperature difference.
Remember that the Earth is a sphere that rotates on itself; due to this,
the amount of sunlight it receives from the sun is not uniform since the planet's
equator will always receive more solar radiation. By receiving more heat, the air in the atmosphere
that is just above the equator warms up more than the air at the poles; this produces something
called "low pressure," which occurs when the air heats up; on the contrary, if the air cools then
the opposite occurs, high pressure occurs. Because?
Everything is due to the thermodynamics of the Earth. Cold air occupies less space, and because
of this, when a mass of air cools, it can compact and take up less space; by taking up less space,
there can be more air particles in the same place, and that causes that area to have a
higher pressure due to because there is more mass. In the opposite case, when the air heats up,
it occupies more space, the particles separate, and this causes the pressure in that area to be
lower because there are fewer particles. In summary: Cold air causes high pressure,
and hot air causes low pressure. How is this related to the polar vortex?
Very simple! Do you remember that we mentioned the air in the atmosphere of the equator?
Well, since the air at the equator will almost always have a lower pressure than the air at
the poles, the cold air from the polar vortex will almost always seek to move towards the
equator because there is more space here, but that doesn't happen. For what? What stops the
vortex from heading toward the equator? We will mention that later; for now,
you should know that when the Arctic vortex is at its strongest, there is only one vortex. Still,
normally, the arctic vortex has an elongated shape, with two cyclonic centers, one over Baffin
Island in Canada and the other over northeastern Siberia. When the arctic pattern is weakest,
subtropical air masses can move poleward, causing arctic air masses to shift toward the equator, as
occurred during the 1985 winter arctic outbreak. The polar vortex can reach extremely low
temperatures, down to -50 °F (-45 °C), which is why they are so dangerous. At the end of
January 2019, a deep cold wave gripped much of the United States and Canada; today,
it is known that it was outbreaks of cold air from the Arctic caused by a weakened polar vortex.
The US National Weather Service warned citizens not to go out because, with these temperatures,
it was possible to freeze in just 10 minutes; hundreds of colleges,
institutes, and universities were closed in the affected areas,
but in the end, around 21 people lost their lives from severe frostbite in the United States alone.
The polar vortex is believed to have had effects on Europe as well. For example,
the winter floods of 2013-14 in the United Kingdom are attributed to the polar vortex that brought
intense cold to the United States and Canada. Throughout history, the polar vortex has
brought waves of intense cold that almost always 's lives end many people's lives.
But if the polar vortex is so dangerous, how have we protected ourselves from it so far?
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Polar Night Jet Also known as Jet Strem
or Jet Currents, these are fast-flowing air currents very close to the poles and are the
invisible walls protecting us from polar vortices. Jet streams can start, stop, split into two or
more parts, combine into a single stream, or flow in multiple directions, including
opposite the direction of the rest of the jet. Jet streams are the product of two factors:
atmospheric heating by solar radiation that produces large-scale polar circulation cells,
Ferrel and Hadley, and the Coriolis force acting on these moving masses.
Ferrel and Hadley polar circulation cells are the large-scale movement of air throughout the Earth;
they are directly related to the tropics since it is in these areas
where the movements of air masses originate. On the other hand, the Coriolis force is caused
by the planet's rotation on its axis and is the same force that produces hurricanes.
On other planets, internal heat drives their jet streams rather than solar heating.
The polar jet stream forms near the interface of the polar circulation and Ferrel cells;
while the subtropical jet forms near the boundary of the Ferrel and Hadley circulation cells.
In simple terms, these hotter-temperature jet streams flow in the tropics from the
equator toward the poles, colliding head-on with the polar vortex's cold air currents.
When two huge air masses like these meet head-on, they don't mix but rather collide,
and this causes both to rise or fall and then return to where they came from.
In this way, the polar vortex remains trapped and confined to the pole and cannot get out.
The Polar Night Jet is that invisible wall that we talked about at the beginning of the video;
the jet currents that cover the entire planet and that are distributed throughout the Earth
are our greatest allies; if it weren't for this, the polar vortex would come out more
often of his region and would cause waves of intense cold in the northern countries.
So far, we have discussed everything that happens due to the north polar vortex,
but… What about the South? The polar vortex found in
Antarctica also undergoes the same changes as the one in the north,
the difference being that the one in the south is much more stable. This is because
the surface landmass of Antarctica is separated from the rest of the world by the Southern Ocean.
The temperatures of this ocean keep Antarctica and the southern polar vortex isolated. However,
it has been seen that it can also break and bring cold waves to the countries near the south pole.
Another notable difference between the two vortices is that while the northern vortex
tends to have an elongated shape, the southern hemisphere Antarctic vortex is a single area of
low pressure that lies near the edge of the Ross Ice Shelf, about 160 west longitudes.
When the polar vortex is strong, the winds at a surface level between 30° and 60° west latitude
increase and are persistent. When the polar vortex is weak, high-pressure areas in the
mid-latitudes can push toward the pole, shifting the polar vortex, jet stream,
and polar front toward the equator. The jet stream "bends" and deflects
to the south. This causes cold, dry air to quickly come into contact with warm,
moist mid-latitude air, resulting in a rapid and drastic change in weather known as a "cold snap."
In Australia, the polar vortex, known there as a "polar gust" or "polar plunge," is a cold
front that pulls in air from Antarctica, bringing showers, snow (usually inland,
with blizzards in the highlands), winds, gusty ice and hail in south-eastern parts of the country,
including Victoria, Tasmania, the south-east coast of South Australia and the southern
half of New South Wales. The threat is always there
Although jet streams keep us safe from polar vortices, it is now beginning to be observed
that polar vortices often break up and leave their regions, especially in the northern hemisphere,
which is where the vortex is not Uniform. These events are increasing mainly due to
climate change and global warming. Jet streams are the invisible wall that protects us from the
threat of ice, but this wall weakens if the planet's temperatures change.
As the planet's temperatures rise, even slightly, our defensive wall weakens and lets in some
of the cold coming from the polar vortices. Currently, these events are still not as serious
or different from what they have always been, but if we do not take care of our planet, the
jet streams will stop giving us their protection. If things continue like this, it is possible that,
in the future, many years from now, our protective wall will completely break down, and when that
happens, planet Earth will enter a new ice age. If you would like to see our video about
the new ice age, we leave the link right here: "Place at this point in the video a thumbnail
with the video about the new ice age, also place the link in the description,
in the featured comment, and a label." For now, the effects of climate change are
beginning to be seen in these parts of the world, but it is not too late; we have enough time to
continue studying these fascinating phenomena and, in the process, learn to live more with our planet
and understand what our place in it is. And you, did you know all this
about polar vortices and jet streams? Let us know your opinion in the comments!