Today is the coldest day in Earth history, and none of us are expected to survive. Not really, but you get the idea. Its in all the papers.
|Puter and Mrs. Puter, along with the boys, go down the driveway to check the mailbox yesterday. Most of the country is like this. Dont believe it? This is their rental home in Phoenix.|
What is causing this bizarre cold weather?
No, this isnt some takedown of global
warming cooling climate change: just basic meterology for your education and entertainment.
A lot of sources are blaming this cold weather on a polar vortex, but that isnt strictly accurate or meaningful. Polar vortices happen year-round, non-stop. All that means is that the air near the North Pole (and South Pole, but let us focus on the North Pole this time) continually rotates in a counterclockwise circle due to the spin of the Earth below it.
So the air spins and spins, sometimes stronger, sometimes weaker based on weather happening in lower latitudes. A big low pressure area in Canada, for example, can swing the polar vortex around a bit faster. Calm weather in Siberia can cause the vortex to get slow and lazy. You get the idea.
So this is a question of air pressure. If the pressure is low over the North Pole, air flows up toward it. Like a gentle vacuum cleaner, the North Poles lower pressure sucks air toward itself. But if the pressure is high over the North Pole, air is pushed away from the Pole in the form of cold, icy, moist winds.
Generally, the polar vortex is strong in winter (low pressure), and it holds its circular shape pretty well. But if the vortex weakens due to higher pressuresthis may be counter-intuitivethe vortex gets all blobby and cold air spills down out of the polar region and into the US.
Get that? Its actually a weak polar vortex that allows cold weather to spill into the United States. As a result, you get heavy snow throughout the northern United States and frigid cold follows. Basically the air pressure is higher at the North Pole than it is in the lower latitudes, and the cold winds blow, baby.
The news media is not quite accurate to say ‘Polar Vortex’ to Blast Frigid Air Over Much of the Country; it would be more accurate to say Weak Polar Vortex Causing Frigid Air Across Much of Country.
Okay, let us try this another way. Ever open a door to your home on a windy day, and you hear the other doors in the house bump a little bit? This is because the air pressure is lower outside your home, and opening a door causes the air inside your house to whoosh out, in order to equalize your air pressure.
Ever open a door in a public library on a hot day when the building is freezing? Note how the door can be hard to pull open at first and makes that weird sound when you pull it? Thats the warm air outside being sucked in by the buildings lower air pressure. In order to equalize the seemingly windy conditions inside the buildingcaused by the air conditioning system blowing like crazythat pressure differential causes the air to move.
This is the Bernoulli Effect: windy conditions are a sign of low air pressure. When low air pressure meets high air pressure, winds whoosh out of the higher pressure area to compensate and equalize. So the pole has higher pressure than the United States, and as a result the icy winds whoosh down to compensate and equalize.
Bottom line: the United States sucks. Wind, that is, from the North Pole. Now you know.