Weather drive

[elte]

Often the Jetstream gets implicated for changes in the weather patterns, how it winds and writhes, ushering air movements various ways.   But the jetstream more responds to instead of creates weather patterns.  Thermodynamics and temperature gradients direct the jetstream, driven by ocean and solar heating of the air.

When warm ocean water moves up to the arctic according to the principle of temperature differences needing to equalize during exchange of thermal energy, it sets up a broad area of atmospheric updraft.  That is a low pressure area that persists, and it deflects the jetstream.  Presently its center has been sitting near Iceland for weeks. .  The jetstream goes in the direction of least resistance. High and low pressure areas block and deflect it.  These systems rotate because of the Earth's rotation, and the jetstream follows the air movement tracks between those high and low pressure systems.

As the Great North Atlantic Low spins, it moves arctic air down into the eastern half of the USA,  while the warm Gulf water moves up and continues powering the Low.  Warm air moves up with the Gulfstream, and it clashes with the cold air the Low is sending down west of it, creating air eddie currents, which, themselves  center around the small lows over the Gulfstream, presently termed the "Nor'easters".

There's more to mention. It's the turning of the Globe that makes the Jetstream move. That is what makes the lows and highs spin. That's how the earth's rotation makes highs and lows spin.

[C C]

Though it would make things tidier in terms of visible recognition, I'm glad we don't have the colored zonal bands of Jupiter's ammoniated atmosphere slash upper weather. The jetstreams that bound the Jovian belts have arguably been measured somewhat faster than Earth high altitude air currents (up to 620kph max compared to 398kph max). We also certainly don't need thousands of kilometers in size storms that last for centuries.

~

[elte]

Good ESP (figurative).  I thought of Jupiter when I wrote that.  The great storm, the Great Red Spot has been weakening. Indeed, the way the jetstream on Jupiter scrapes it,  puts a spin on it.  Glad our winds here are slower that way

(620kph max compared to 398kph max)

.

Here the way the Low persists near Iceland reminded me of the Spot on Jupiter.  And here the tendency of the Low to persist there in the N. Atlantic helps encourage a somewhat corresponding High out west, and its dry weather.