Yesterday’s study had some remarkable features that prompted me to take another look at the same scene today. There have been some changes worthy of comment, including a flaw in the presentation. What I am going to do today is to set up all of the same images as I add comments. Most of this will be focused on the vapor stream in the center that arises from a rainforest region, which was the most interesting of the three. I encourage you to open yesterday’s letter in a separate tab so that each pair of the daily images can be compared side by side with a quick click. In this first image the three main streams are still there as before except that now everything has been carried a few hundred miles to the east—with one exception: The early southbound stage of the center stream has not shifted eastward at all for a quite long distance, until just before making the first big turn. There must be a reason for so much stability in the winds employed up to that point, but I have no idea of what it would be.
Next, the jetstream winds, which are surprising to me in a couple of ways. Today you can see two distinct but faint lines crossing the central part of the continent, which did not show up yesterday. I think the lower one of these represents a piece of the regular red-zone jetstream pathway, which from there mostly fades away completely in the west but picks up considerable strength as a vertical streak far to the east. The strong jets that pass across the southern tip of the continent then properly belong to the regular yellow fringe of the green zone, and did so as well yesterday, which I must admit to having misread. The source of the upper of the two faint wind lines across the center of the continent is a complete mystery and not material to this discussion.
The 500hPa air pressure image, shown next, is a reliable guide to all jetstream pathway locations in general but does not have much to say explicitly about how likely the various strong and weak stretches of wind will be seen on other charts along each of the winding pathways. That part takes some interpretation skill when the speed-bursts are short and scattered, or just missing altogether for long stretches. The pathway on the yellow fringe of the green zone normally has more activity than the red-zone pathway, and today is a good example, as seen by correctly referencing this image to the one right above:
On this next map you can see that the continent has remained largely free of clouds, which means there has been no interruption that would cause the vapors to condense. Clouds finally do begin to appear in the approach toward the spot where the stream makes its sharp turn, as seen in the top map, and as the turn takes place this time a light rain begins. Then there is another cloudy stretch approaching a second sharp turn followed by a much enlarged rainfall and then snow. As before, see how the stream falls apart at this point on the top map.
Today’s anomaly map, compared with the one yesterday, reveals the same generally eastward movement consistently found on all the other maps, leaving no doubt whatsoever that this particular stream of water vapor, transported by winds from the rainforests at the top of South America, at the same altitude as that of the jetstream winds, is the primary source of all the unusual heating of the surface air directly below. The entire track of heating is quite visibly and unmistakably connected. The most fascinating part is the extraordinarily high amount of temperature increase at the very end of the journey, as much as 16-17C in the center of the strongest part, apparently caused by only the small amount of vapor (see the top map again) that remained after so much of the stream’s content had been lost by precipitation. Even that small amount had to be enough to more than double the amount of moisture in the ambient atmosphere of this exceedingly dry section of the globe, this being the only way to account for so much heat, via the powerful greenhouse effect naturally embodied in water vapor.
If meteorologists and climate scientists are still searching for the full reason why the Arctic and Antarctic regions are able to warm up two or three times as much as the planet as a whole, whether at present or historically, what you are seeing here is a perfect example of a basic set of phenomena they need to be looking at more closely.
Carl