Climate Letter #2073

PW’s greenhouse effect—cont.  Precipitable water (PW) has a genuine greenhouse energy effect on Earth’s surface temperatures.  To me this is nothing less than a fact, and I can claim to be the first person to make the discovery.  The PW greenhouse effect is comparable to that of the established greenhouse gases, with one major exception:  it is expressed by changes in daily temperature anomalies rather than by changes in anomalies that develop over much longer periods of time.  The reason behind this difference is not difficult to understand.  The greenhouse effect of any particular agency is totally dependent on the existing magnitude of that agency as a physical component of the total atmosphere directly above any given location on the surface.  All but one of the greenhouse gases are standardized by the same principles in this respect.  Their quantities are relatively evenly distributed throughout the entire atmosphere, from its surface to the very top, and the same in all directions.  Molecular distribution is everywhere expressed as a largely constant ratio of a gases’ parts relative to the number of parts of all other atmospheric molecules.  Local deviations occur, but they are soon brought into balance with the prevailing globe-wide standard.for that gas.  Changes in the global level are imperceptibly small on a daily basis, and may barely be noticed from one year to the next.

One greenhouse gas, water vapor, does not follow most of these principles. Distribution is for the most part radically uneven, especially horizontally but also vertically. The ratio of molecular parts to other molecules in any location also makes large and frequent shifts. A better standard of measurement for relative atmospheric content has been set in terms of total molecular weight of all the molecules within a vertical column of air measuring one square meter from the surface to the top. Existing instruments can make these measurements at all locations, but not for water vapor exclusively. In practice, the measurements are bound to include the molecules of all the different states of matter into which water vapor condenses in addition to those in a gaseous state. This total happens to be a precise match for the substance we know by the name of PW. Having these measurements available and all mapped out has provided a perfect opportunity to investigate the possibility that PW generates an independent greenhouse effect. And so it does, in a surprisingly novel way: the effect is only revealed by PW in a certain format, and only when comparisons of its power are made, one day at a time, with imagery found on corresponding maps of daily temperature anomalies. They both tend to move up or down together, with amazing consistency. The correspondence is most vivid when they both arrive at extreme level simultaneously, lows as well as highs, in both timing and magnitude. Magnitude for PW power is always expressed logarithmically in the comparison. This is the same kind of signature that is common to the greenhouse effect generated by CO2 and all of the other ordinary gases—further proof of the basic fact being claimed by this presentation.

Just the one process of comparison with anomaly imagery is what makes it possible to gain an insight into the magnitude of PW’s greenhouse effect as well as the fact. The comparison does even more, by adding views of other maps that often show PW operating in clear sky conditions. These situations indicate an absence of any kind of significant condensation by the water vapor present in the PW measurement. One can thereby compare the greenhouse power of PW in an exclusive situation with powers expressed in other situations where condensation is in evidence. I have not detected much difference in this power relationship except in certain seasonal situations involving clouds and heavy rainfall. This bit of information should be useful, but needs further verification.

In gathering all of this information, as previously noted, I have chosen to focus my attention on regions away from the tropical belt, where PW and water vapor distribution both become less and less concentrated and more and more erratic related to observations of locations drawn closer to the poles.  A little more than two-thirds of Earth’s surface is still being covered after this separation is taken.  This identical territory is where the strongest temperature anomalies are also found, and that’s not all.  The very same territory also plays host to atmospheric river (AR) activity, and, yet again, serves as the home of the wind systems that give rise to jet streams and their own unique powers of influence.  It is truly special. The tropical belt, by comparison, has far more regularity and stability.  It contains heavy loads of PW but they are pretty well stuck in place. They don’t go anywhere like the PW contained in ARs does.  The greenhouse effect of tropical PW is quite real, and most probably the same as everywhere else, but its magnitude is narrowly foreclosed because of natural limits set on how high it can go without condensing into heavy rainfall material.  Climate change is real but muted under these circumstances.

Outside of the tropical belt, thanks to atmospheric rivers and their ability to distribute PW in a dramatically consequential manner, and thanks to all of the PW in these rivers having powerful greenhouse energy generation that has an immediate effect on surface temperatures directly below, the prospect of all this activity having a special kind of influence over climate change development seems almost inescapable.  Daily temperature anomalies, both high and low, are always going to move around, and there is no reason to assume that they will always balance out at the end of each day, or after any particular number of days.  If unbalancing can in fact occur, is there any limit to how far it can proceed? This is a subject worthy of deep investigation, which no one person will ever be able to resolve, but can still think about.

Carl