I want to revisit the big North American anomaly today because it offers such a great illustration of the connection between Total Precipitable Water (TPW) and surface air temperature. This time I won’t even bother to do an analysis of where the TPW is coming from, or how quantities can be broken down into two uniquely separated strata. We’re just interested in the effect generated by the combined total. Surface air doesn’t appear to care at all about any of the nuances, but rather just the total, so why can’t we? Let’s assume for now the total is all that matters , but still save time for further investigation of those nuances in the future. So TPW will be treated monolithically as if it had all of the very same kinds of properties as any well-known greenhouse gas, other than being a whole lot more irregular with respect to amounts of everyday presence in the atmosphere. Plus it’s a whole lot stronger. There will also be a little surprise at the end of the letter. Now for the anomaly map:
This map looks a lot like yesterday’s map except that everything has shifted eastward by around a hundred miles. We know why this movement occurs because we can see the same sort of thing happening every day on a universal scale when we study the animated website portraying the behavior of TPW streams. (http://tropic.ssec.wisc.edu/real-time/mtpw2/product.php). There is a special greenhouse effect that comes and goes each day which surface air will respond to in full, with no second thought about origin. Also, be sure to note on the map how a cool down has continued to develop over Arctic Ocean, something we can hope is unstoppable for awhile. Now for the TPW update:
What I like most about doing this particular map comparison starts with the visualization of the strong brown feature tilted downward across the center of the 48 states, surrounded by all sorts of gray stuff. The brown part jumps out at us with a message—look at this same area on the anomaly map for a strong reading of the warm type. We saw it yesterday and we see it again today, perfectly well-matched. We can even get the value readings and start to do some calculating about relationships. Now you might ask, what about all the equally warm anomalies to the north where nothing on the TPW map is brown, just shades of gray? No problem at all, except that the sharp visualization factor is missing. We can still get good readings for TPW everywhere, and we know that it takes less and less TPW presence in the atmosphere to cause any additional amount of surface warming as you proceed toward the north—where natural surface conditions keep getting drier and drier. This view may be unusual, but I am convinced that any double of TPW value for a given location on a given day of the year, no matter from what level, provides enough energy for an immediate extra 10C in surface air temperature. The greenhouse effect of TPW is the only thing responsible, and it is inescapable. Anyone who does the study should have no trouble seeing it, every day of the year, in all places outside of the tropical belt.
Now for the little surprise. On the above map of air temperature anomaly, out in the Atlantic Ocean and off the coast of Newfoundland, you can see a rather large blob of warm anomaly that looks like it runs as high as 6 or 7C in the central part. This is a most uncommon phenomenon for air over a mid-ocean region, and it has nothing to do with TPW readings. This one is all about water temperature. As a general rule, surface air temperatures are closely tied to corresponding surface water temperatures, with the latter being dominant, and having its own set of reasons. This holds true for anomalies as well as everything else. On this next map of sea surface anomalies you can see where the effect is coming from—water temperature anomalies that range in spots all the way up to the top of the scale, which is 6C. It is a reality, it’s extreme, and it’s probably not a good thing. That’s all I can say.
Carl