This is just a quick speculation.
While watching the weather on WeatherNation (much better than The Weather Channel that is now un-Reality TV much of the time) I notice an odd pattern.
Has an interesting “stream live” button that does give you a video feed, but only after sitting through a commercial. Still, much better “click and go” than many other sites. It is now my “go to” weather channel on TV. That there is a ‘click and go’ option on the computer just earned them a bookmark.
So what they were showing was the cloud cover and rain patterns. I noticed that the cloud extended out into the Pacific to the end of the radar. Then noticed a large fat ‘tongue’ of clouds down over the middle prairie. Exactly where you find a similar cold blob of “Canadian Air” when a mobile polar mass moves in. That got me thinking.
We had UV drop, so the stratosphere cooled off. Also less UV going into the oceans so they will slowly cool. All that caused the atmospheric height to lower (even NASA noted that less drag was on satellites). At the same time, the Total Solar Irradiation is not much different. So, in places like the Tropics, there will be the same total heat driving the same water into the upper Troposphere. (Perhaps even more as the prior UV carried energy is now showing up in longer wavelengths that are absorbed at ground level). So what happens then?
Thunderstorms and Hadley Cells, Oh My!… The hot air rises, then catches a Cat-2 hurricane force wind sideways toward the poles. Especially toward the winter pole where it forms the Polar Night Jet and then descends as very cold air into the polar vortex.
“The polar vortex is not a recently discovered phenomenon; in fact, it has been talked about in the meteorological world for decades,” AccuWeather.com Senior Meteorologist Bernie Rayno said.
A polar vortex is a large pocket of very cold air, typically the coldest air in the Northern Hemisphere, which sits over the polar region during the winter season.
The frigid air can find its way into the United States when the polar vortex is pushed farther south, occasionally reaching southern Canada and the northern Plains, Midwest and northeastern portions of the United States.
When Vortex Meets Humid
So my muse was just visualizing a more flattened Polar Vortex (and general downwelling cold air at the poles) as the column height is lower, and seeing it as colder since the stratospheric air starts out colder with less UV heating. That displaces colder air further toward the equator, and more often. So what happens when the greater extent and degree of cold pole runs into the same or warmer and wetter tropical source air?
Clouds. More of them, more widely spread, more complete cover, and also of a somewhat more compressed height. In short, a more effective cloud cover (and likely with more rain too).
So this would mean an increase in the albedo of the temperate band, and much less warmth at the surface. Something I’ve been experiencing this year in the yard. In many years, May has been warm and summer like. This year it is cool to cold and winter like. Heck, we even have had rain a couple of times. Almost unheard of and you need to go back many years to find historical similarity.
We’ve also had more rain in the areas where that air collision is happening, including the “flooding droughts” in Texas…
So while that is ‘anecdotal’ observation, it is the thing that forms a “dig here!” for confirmation (or refutation).
That’s my muse. Related to Stephen Wilde’s ideas, though he looks more at the position of the jet stream and how it wiggles, while I’m just looking at the relative temperature and what it does to humidity. (It is possible I’m looking at one part of ‘how it works’ and he is describing the overall context and results). But I’m not sure if this is already incorporated in other folks stuff. At any rate, I think the idea of looking specifically at cloud albedo changes based on atmospheric height changes and ‘polar jet strength / polar vortex and downwelling strength’ causing stronger temperature differentials is worth breaking out as a specific question.
To me, it looks very much like things are more cloudy and cold. Both in California and looking at the weather maps of other areas. Actual data would help and a full analysis would be enlightening. Sadly, I’m pretty sure we have lousy cloud cover data… and I’m not even sure where to find that.
If true, this brings in two other factors for crop growth. First off, less sunlight at ground level. Some crops want “full sun”, others are ok with “partial shade”. IF we have a lot more cloud cover, some crops will take longer to ripen. Perhaps too long. Second, degree days. As it is colder, it will take longer to ripen for any given crop. You need a certain number of degree days for a given crop, and if the days are cool and cloudy, it takes more days for that degree x days product to reach harvest. This all combines to say “longer growing season needed just when frost leaves later and comes back sooner” and that folks will need to shift to cooler environment crops and smaller degree days to harvest.
I think I need to practice making buckwheat pancakes…