Today we will head down to South America for map reading, where I see some things of interest. We may even spot the hottest anomaly on the globe for this day. First off, the precipitable water image, where there are three large vapor streams to investigate. Two of them emerged from tropical ocean waters, one on each side, and the third from rainforests on the north end of the continent, which thankfully still exist. Tree respiration is a great producer of water vapor, not to be overlooked.
As you can see, each of the streams came to an abrupt halt before reaching the Antarctic continent, and each of the endings has its own characteristics, which need to be described more fully. Each stream also produced warm temperature anomalies on the surfaces down below, which are of greatest interest for the one that moves over land. And each is also involved as a source of considerable rainfall, where we will see two different processes at work. Lets go next to imagery of what brought each of the vapor streams to a halt. This will get a little complicated because three separate pathways of jetstream wind patterns are involved and only two of them show up on the regular jetstream map. Here is where we see those two:
The third pathway is in between the two that you see above, but on this day its velocity is not strong enough to make an appearance, yet it will still be enough to let it function as a stopper. Its location, along with the other two, is firmly established (as always) by virtue of the air pressure figuration that I will show on this next map. The “unseen” (except for a tiny bit on right side) pathway simply coincides with the yellow fringe of the green zone. The “upper” jet pathway follows a course separating the darker and lighter sections of the red zone, while the inner pathway follows the thin light blue line. Here is the air pressure map at 500hPa where the visible fits can be established:
Now I can finish the explanation. (I frankly did not realize when I started how this was going to end up. The complications uncovered have made it all the more interesting.) Starting with the Pacific vapor stream, the main body that shows up in bright blue on the top map first slams into the red zone jet, which causes it to unfurl and widen out into a mass of vapor—which mostly piles up by condensation and rains out, as we’ll see later. This mass of condensing vapor—now in dark brown—still has forward momentum, which carries it directly into the jet pathway that we can’t see, where it flattens out and stops completely, exactly along the line of the green-zone fringe, except for a few trickles of vapor that are able to keep going. The central vapor stream has a similar type of experience, plus some extras, including a sharp twist added in the red zone, a full stoppage that is carried out in two stages, both of which have rainfall, followed by a leak of vapor at the end which is just strong enough, at that point, to engage in a warming anomaly that would be of noteworthy strength in any other part of the world.
The Atlantic vapor stream has had a quit different experience from the other two because of the way it contacted the red-zone jetstream. Instead of stopping it was picked up by that jet just where the jet was making a tight bend and heading onto a more southerly course, then carried along for some distance on the western edge of the jet, losing vapor to rainfall in the process (see below) and finally expired when the arrangement made contact with the green-fringe pathway at the very spot where this pathway becomes visible to us.
This next map will show how much rainfall was produced by each of the three streams as their ending stages unfolded. In each case the vapor condensation appears to have been caused by the stream pressing up against the forces of resistance provided by the jetstream winds. Also, note how very clear the skies have been on the main continental pathway of the central vapor stream.
Just one more map to show the temperature anomalies produced by these vapor streams. They are quite distinctive and pronounced but otherwise not unusually interesting. This entire exercise should mainly be taken as a clear demonstration of critical interactions that take place in confrontations between vapor streams and jetstreams. The fact that such interactions occur at all serves as evidence of the very high altitude which the vapor streams have ascended to and are to be found. This information is not readily available anywhere else that I know of. It seems to me that the way of life the vapors experience up there is quite different from that of vapor down below, with a number of unique features and effects. Maybe it deserves a more than ordinary level of separate consideration in the sciences for that reason?
Carl