Tuesday, January 29, 2019

Two reasons eastern US is freezing despite climate change

Its so predictable. A big snowstorm or colder temps bring out the climate deniers. This week’s historic deep freeze spreading across the Midwest, North East and as far south as Atlanta (just in time for the Super Bowl) may leave you wondering, if the world is warming, why are we seeing colder temps?

It’s actually ironically more proof of climate change. Two reasons: more cold air is coming down by land and less warming is coming by sea.

1. The polar vortex is usually blocked by temperature differences. The cold arctic weather is blocked by  a life preserver of warm air, driving the jet stream in a tight circle. But as sea ice disappears, the arctic region warms faster than the rest of the planet. So the temperature DIFFERENCE has dropped. This makes the polar vortex more squirrelly because the jet stream punches through a weakened barrier. This is happening more often, bringing bitter cold deep into the eastern half of the US.

High altitude, east-to-west winds known as jet streams rely on the difference between cold Arctic air and warm tropical air to propel them forward. As the air in the Arctic warms, those jet streams slow and prevent normal weather patterns from circulating—floods last longer and droughts become more persistent. One study published in Science Advances last October predicted extreme, deadly weather events could increase by as much as 50 percent by 2100.

2. The Gulf Stream is slowing. The Gulf Stream brings warm water up the eastern seaboard, past Greenland and down past Europe, making those areas warmer than they otherwise would be. Paris, for example, at 48.8 N latitude, is as far north as Minnesota. (The US/Canadian border was set to 49 degrees.)

But as Greenland melts,the fresh water blocks the seawater, slowing the cyclic flow. Look at the map of global warming temps. Look at the dark blue dot by Greenland. Smack dab on the peak of  Gulf Stream.


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