Yes, another “inner word”. I use “pivnurt” as a single word. It is the pronunciation of the formula
or the “Ideal Gas Law”. I first started doing that in high school chemistry class when we were first learning and memorizing the formula. So for years, any time doing chemistry or gas problems, I’d just apply pivnurt and not even notice that it was a “me word”…
So what IS the “Ideal Gas Law”? It came about from a synthesis of several other earlier observations about gasses and chemistry. It incorporates Boyle’s Law and Charle’s Law.
The ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behaviour of many gases under many conditions, although it has several limitations. It was first stated by Émile Clapeyron in 1834 as a combination of Boyle’s law and Charles’s law.
So what are those parts? P is pressure. V is volume. If pressure goes up, volume must go down as long as all other things are kept equal (that is, the other side of the equation does not change). On the other side, n is the amount of stuff you have in “moles” (a particular number of atoms or molecules of ‘stuff’). For the atmosphere as a whole, n is almost a constant. (More on that a bit later). R is a constant. T is temperature. So if Temperature goes up, either Pressure or Volume must go up (for a constant amount of gas).
There are a few caveats on pivnurt, but not all that many, really. It’s an ideal gas law. Real gasses can vary from it a little bit. For most practical purposes, natural gasses are close enough to ideal to not care about that point.
So what good is it?
It’s a great tool for solving all sorts of chemistry and engineering problems. For example, if you fill a cylinder with some air and fuel, and ignite it, you know a couple of things. The fuel and air burn getting hotter, so T is going up. The big fuel molecules get broken down and combined with oxygen making CO2 and H20. So take methane. CH4. It combines with 2 oxygen molecules to make CO2 + 2( H2O). 3 molecules at the start, and 3 at the end. All gasses. No change in n in the formula. So that flame puts pressure on the cylinder via more T, not more n. All the work you can do with an engine comes from that heat. Put a piston in the bottom and you have a gas engine. The work you can do comes from the excess of P, changing into a larger V, as the piston moves down. Eventually restoring equilibrium with that larger T. So pivnurt lets us see how an engine works, on the chemical and pressure level. Turning T into P into V into motion.
Or go the other way. Pump air into a tank or a car tire. V is getting smaller, so P goes up.
The Air We Breathe
This same law applies to the atmosphere. IMHO, folks have spent far too much time looking at computer models and far too little thinking about fundamental laws of nature. So, some thoughts on what pivnurt says about AGW.
As a first approximation, assume that n is a constant. This isn’t quite true. As water evaporates, n gets bigger from water vapor. As rain condenses, n gets smaller as water vapor leaves the air and turns into a liquid. But for now, on a global basis, assume “it all averages out” (even though it isn’t a necessity). Also, if n is nearly a constant, P will be nearly a constant as well. Yes, we have “highs and lows” in weather systems, but they are down in the millibar range. Bar being “one atmosphere” of pressure. Millibar being 1/1000 of a bar. So it’s a small variation and largely localized. We’ll come back to that too. But for now, assume n and P are constant.
That means V and T are the only things that can change much. Since pressure is set by n and gravity, both held near constant, it can’t change much on a global basis. If we have global warming, we ought to get more atmospheric volume. As we’re on the surface of a sphere, that’s got to show up as greater atmospheric height. We had that happening up until the sun went quiet. When the sun went quiet, the atmospheric height shortened. (So much so that satellites were having less drag and NASA made mention of it). That, per pivnurt, says that things got cooler.
Note that pivnurt says nothing about WHERE the atmosphere got cooler. Stratosphere, surface, whatever. It’s also possible that some parts warmed while others cooled. The “net net” of it all, though, is that height got lower. V got smaller. T was, on average, shrinking. IMHO, this is MORE accurate than just looking at surface temperature since it is a measure of the total atmosphere.
About that n…
OK, what could make that less than accurate? Well, n is assumed constant on average globally. Yet that isn’t a constant. More heat would evaporate more water and make more water molecules in the atmosphere. That would make n larger. Colder air holds less water vapor, so when very cold n drops (which is another way of saying that it rains, snows, hail falls, etc.) So when it is hotter, with n larger, both P and V ought to get larger. Now I don’t remember anyone saying that atmospheric pressure was significantly or even noticeably higher in the ’90s, so IMHO there was not a lot more n happening. There could have been some, though, but not a whole lot.
Most likely, that added V was all due to added T, not added n.
Now, as V has gotten smaller, we’re getting a bit more rain. As things have gotten cooler, we’ve had more water leaving the air. Now I can’t say if that’s less n, net of water going into the air. I can only speculate on it. But, IMHO, we’ve not had stories of either a massive increase nor a massive decrease in global humidity. That’s why I was happy to assume n is nearly constant up above.
My thesis has been that the shift to a sleepy sun has more IR causing prompt evaporation from wet water surfaces and less UV / Blue being absorbed deep in the oceans. That a 30 year ocean warming from deeper UV / Blue into water has been replaced with gradual cooling of all that water as IR causes surface evaporation instead of storing as deep heat. That added source water shows up as added rain / precipitation, not more humidity. But say I’ve got that wrong. Then the added rain means less n (and in short order we ought to have reports of unexplained very low humidity…) and some of the lower amount of V would be from water leaving the air. Yet, if that is true, then “water vapor feedback” ala AGW theory is wrong. Water is driven by the solar cycle, not CO2.
So looks to me like either the “water vapor feedback” is all wrong (n getting smaller), or we have nearly constant n and the sun is driving the lower V (and required lower T). Also the sun is causing the added rain (so my UV / IR thesis has legs…)
I just don’t see any way out of that logic box. Either n is nearly constant, and the solar changes caused less T (so CO2 is not the driver); or n is variable, and has varied with the sun, not with CO2. Pivnurt says so.
This is just a few odds and ends on the same line.
First off, if pivnurt is to hold, then any increase in global warming (more T) and any increase in water vapor feedback (more n) MUST show up in more PV. In the absence of any notable change in P, that can only show up as V, that on the surface of a sphere, must be height.
It looks to me like accurate measurements of P, the standard atmosphere pressure, and H the top of atmosphere height, give us a fairly good reading on n and through that water vapor content of the air, and T via atmospheric height. They act as a cross check on all the other more hypothetical and manipulated lines of reasoning and data.
Are there complications? Sure. Combustion puts some amount of new molecules into the air, making minor changes of n and of mass (so P is slightly changed). But the null case of not much change of atmosphere and humidity would only be confounded by a very peculiarly perfect offset, so not very likely to happen. Why worry about a very unlikely case until you know it exists? That can be put off until a later time when and if that case shows up. Certainly none of those changes showed up as quickly as the atmospheric height changed.
It is also possible for there to be offsetting changes. A warmer stratosphere could be coupled with a cooler troposphere, or vice versa. But that ought to show up rapidly in the satellite data. We ought to be able to figure that out very quickly. (This is another way of saying that the ideal gas law applies to a well mixed gas, and the atmosphere isn’t all that well mixed). So looking a bit at things like height of the tropopause and relative temperatures of stratosphere, troposphere, mesosphere, etc. would yield useful clues about how much non-mixed things are. Is the change of height due to a change of relative temperatures and / or relative placements of those layers.
Yet that, then, would also tend to toss a monkey wrench into the AGW mantra. If such things happen as a matter of course, then that implies a degree of variability in the surface temperature records that is unconnected with actual global warming; but only to changes of air mixing. If the stratosphere can cool all on its own, then the surface ought to be able to warm all on its own. If air mass ratios between troposphere and stratosphere are variable, then one must look at the heat content of BOTH at the same time, not just the surface.
In short, I think PV=nRT puts some tight bounds on what can happen to things like atmosphere height and surface pressure; and those things are relatively easily measured. That implies we really need to start accurately measuring top of atmosphere, tropopause, etc. along with average surface pressure. They can tell us things we want to know.
For water vapor feedback to be strongly positive, P must go up or V must go up. V is down, so it must be P, up a lot. A simple measure of P can falsify the notion of more water vapor in the air.
For AGW to be true, with lots of warming, T must be up. That means V must be up (as n is either constant, or if water vapor feedback is true, n is rising) for any given P. Yet V is down. So where’s that exceptionally high pressure? How can that be squared with the idea of more storms (that have lower P) lowering the average p?
So, IMHO, putting a V and n box around AGW constrains what can be asserted about water vapor and T.