Image Thread 28

[hazard]

I think this glib explanation is somewhat wrong.  It has very little to do with the strength of the jet stream; the jet stream isn't an object in itself but created by the general circulation of the atmosphere.  What's happening is that the atmosphere is trying to balance the heat which is mostly absorbed in the tropics and equalize the temperature by transferring it towards the poles which are cooler. 

By increasing the temperature, you increase those intrusions of warm air to the high latitudes, which by necessity displaces more cold air to the low latitudes.  You've increased the amplitude of the waves (particularly Rossby waves) by increasing the energy in the system.  The jet stream can be stronger or weaker in this new system, depending on weather -- it doesn't have to be zonal flow to be strong.

I think you are both wrong here.

Well, more like not exactly right, although Labster gets closer.

The problem, I think, is that the total amount of energy in the system is changing. If the total amount of energy was stable, even if it was noticeably warmer than today, the jetstream would likely be a stable phenomenon.

Also; if you presume that the Earth is a tiny section of the surface of a sphere the size of Earth's orbit centered on the Sun the insolation at the poles is not notably smaller than the insolation at the equator. It's just because the Earth is, itself, also a sphere that the same amount of sunlight from the Sun's perspective is spread across a much larger surface area from Earth's perspective, and most of it is currently snowy white, which reflects very well. I wouldn't be surprised to have the temperature at the poles noticeably increase as a result of higher temperatures exposing water and rock, with a much lower albedo, than the current ice and snow.