Polar warming, jet stream, and lower latitudes

Source: Arctic ice melt 'already affecting weather patterns where you live right now' | Environment | The Guardian

The chain of events that links the melting Arctic with weather to the south begins with rising global temperatures causing more sea ice to melt. Unlike on the Antarctic continent, melting ice here exposes dark ocean beneath, which absorbs more sunlight than ice and warms further. This feedback loop is why the Arctic is heating up much faster than the rest of the planet.

This in turn narrows the temperature difference between the Arctic and lower latitudes, which is crucial because it is the temperature gradient between them that drives the jet stream wind, which streaks around the pole at up to 250mph and about 8km above the surface.

The jet stream forms a boundary between the cold north and the warmer south, but the lower temperature difference means the winds are now weaker. This means the jet stream meanders more, with big loops bringing warm air to the frozen north and cold air into warmer southern climes.

Furthermore, researchers say, the changes mean the loops can remain stuck over regions for weeks, rather than being blown westwards as in the past. This “blocking” effect means extreme events can unfold.​

Ahh, a link between polar and lower latitude weather events.

Bob Wilson

 

Put wind turbines between the two ...

Bob Wilson