Climate Letter #1697

I recommend that you take the time to learn more about the content of the animated version of precipitable water readings published by the U of Wisconsn, and then become a regular visitor. Here is the best link for regular access, preset to 120 hours of tracking: http://tropic.ssec.wisc.edu/real-time/mtpw2/product.php….It offers a 5-day history in 3-hour time slices leading up to what is displayed on the U of Maine global weather maps, which are limited to presenting the mean of eight slices from one day.  The animated version will quickly impress you with how rapidly the changes develop day after day, and how those changes are going on practically everywhere you look, all the time.  Because all of that movement is guided by winds, at both high altitude and low, we get a clear picture of the ways and frequency of all relevant wind pattern changes.  The winds also helps us distinguish differences in the relative amount of precipitable water that exists at of the various altitudes, as linked to their direction of movement.  The high ones only go from west to east, even when twisting around, while many of the low and more heavily moisturized winds near the equator stay on regular east-to-west pathways.  

The animated version has a number ot regional domains for close-up views, minus a few that I hope can be added some day. Only one view, Europe, includes a full share of the North Pole region, showing the few bits of water vapor that are able to get inside every day. These bits, plus a few more on the other side not shown, will surely stimulate further increases in warm anomalies if their numbers keep growing. The Alaska domain provides another view of vapor bits that are approaching the pole, but not to completion. This domain also has more details (briefly) of the broad stream we followed in yesterday’s letter.

The Tropical South America domain is quite interesting because it leaves the impression that practically all of the rains feeding the Amazon basin are moving in on the backs of easterly winds that draw their water from the Atlantic. The entire range of Andes mountains along the continental west coast appears to act as a barrier against the entry of Pacific waters, which may not even be a viable option. In the equatorial Pacific most of the heavily moisturized winds also appear to be blowing from the east right now, a signature of potential La Nina conditions that predictions say are in the making. One can wonder what would happen to the Amazon rainforest if the Atlantic equatorial winds were to start shifting in direction the way they do in the Pacific.

Most of my interest these days is focused on the one specific type of wind that carries large amounts of precipitable water.from ocean surfaces to very high altitudes. The animated maps show them emerging mainly at latitudes of 20-30 degrees North or South, from locations where conditions seem to be most favorable for sending them aloft in steady streams. The number of streams and their locations are not fixed by any means. You can see how they keep popping up and/or moving sideways, as if searching for ideal conditions. It makes one wonder about whether streams of the future will evolve in some way in response to changes in ocean water temperature and overhead cloudiness that are known to be forthcoming. Will there be significant changes in their power to produce air temperature anomalies in the higher latitudes? Climate science at its highest level ought to be more forthcoming about what these great new maps are telling us, and get more involved in this study!

Carl