Thread by @trollhuntress

"Global warming" can make winter colder.

Jet streams are a fascinating piece of the climate science puzzle that most people have never considered. Learning about this one simple thing for 5 min explains SO MUCH.

When everyone knows this we will all accomplish more.

THREAD

1. First point:

"Weather" (clouds, storms, rain ect.) is pushed around by wind.

There are some major, reliable, high altitude winds like the jet steams that push weather around the Earth in predictable patterns.

2. Here's how jet streams work:
The sun warms the air around the equator all year. The warm air then moves up and towards the poles. The air coming off the poles towards the equator is freezing cold. Where the warm air and cold air collide the jet stream is formed.

3. The jet stream is like a fast moving (about 275 mph) river of air that goes from West to East (due to the Earth's spin.) When a strong steady flow of hot air hits a strong flow of cold air the jet stream is formed in a fairly straight line.

4. The temperature doesnt stay the same all of the time. The Earth's position changes during the year causing the sun to warm it differently. It also spins so is cooler at night etc. So a normal jet stream tends to look like this and shifts predictably with seasons.

5. These high atmosphere winds bring us much of our weather, & because they are so reliable in the way they move & change from winter to summer they bring us mostly predictable seasonal weather. So predictable, in fact, that our ecosystems have developed in response to them.

6. Global warming is causing warming at the poles. (Among other things.) When the air at the poles is warmer then the interaction between warm and cold air isnt as forceful which causes the jet stream to slow and meander like a slow river on an open plain looking more like this.

7. This brings much colder air further south causing winter cold and storms in the US that previously were kept in Canada, while the Arctic has warmer than average temperatures. It also causes changes in rain and snow patterns.

8. The current cold spell includes a related phenomenon. Scientists believe a meandering current of air cut through the polar vortex this year causing it to split in two with one segment getting pushed south to hover and swirl over the US, waiting for spring to dissipate it.

9. Another rarely mentioned result of predictable air currents is that when the strong current of air like a jet stream encounters a storm at high altitudes it dissipates the swirling force, keeping storms small.

Weaker jet streams = bigger storms.
tampabay.com/hurricane-guid…

10. Climate science is complex with lots of moving parts, many of them happening out of sight high above the Earth.
Everything we can say about it is over simplified and sometimes not yet known.

This makes it easy to ignore or deny.

11. Beyond that anyone profiting off (or using) coal, oil, plastic etc. has a vested interest in ignoring (or even suppressing) the understanding of climate change. We all love our cars plastics, heat, convenience...

12.The warmer the Arctic gets the more the jet stream will shift and meander.
Our winters will get colder, summers drier, storms bigger. Weather patterns will change killing eco systems.
This is why sharing info on climate change is absolutely vital today.
/end

Some additional links to read more:
insideclimatenews.org/news/02022018/…

One way the jet stream can move the polar vortex
washingtonpost.com/wp-srv/special…

More on the vortex
"...can cause kinks in the jet stream so that, instead of flowing west to east, there are a lot of dips and ridges. And the waves in the jet stream can disrupt the lower (tropospheric) polar vortex, break off a lobe and force it south."
washingtonpost.com/weather/2019/0…