Guest post by E.M.Smith
Temperature Inversion
The Event
We’ve recently had some very cold days in International Falls.
This posting:
http://wattsupwiththat.com/2011/01/21/new-record-cold-tempertures-in-minnesota/
has a nice write up of the -46 F new record cold. ( That’s -43.33 C – still damn cold.) This is not just another “oh a record” posting. I’m asking “what does this mean about the magnitude and time scale of CO2 action?” and finding it means “not much” and “very short term”. But first, the data:
RECORD EVENT REPORT
NATIONAL WEATHER SERVICE DULUTH MN
518 PM CST FRI JAN 21 2011…RECORD LOW TEMPERATURE SET AT INTERNATIONAL FALLS MN…
A RECORD LOW TEMPERATURE OF -46 DEGREES WAS SET AT INTERNATIONAL
FALLS MN TODAY. THIS BREAKS THE OLD RECORD OF -41 SET IN 1954.
Last night set a “daily record” too, but not a new “all time record”.
Here is a monthly chart so you can see if anything “interesting” happens on that scale:
And here is a ‘close up’ on that week in particular:
International Falls week ending 22 January 2011
The Meaning
OK, so what does this mean? Typically it means that there was a temperature inversion on a cold clear night. (I was watching The Weather Channel when they reminded me of this with a brief coverage of how this particular cold record happened). Normally, temperature decreases with altitude, during an inversion the temperature is coldest at the surface and warmer at altitude. (The “D-C” segment in the diagram up top. It is showing how air from the ‘normal’ “A-B” segment, if descended, would result in an inversion).
Under certain conditions, the normal vertical temperature gradient is inverted such that the air is colder near the surface of the Earth. This can occur when, for example, a warmer, less dense air mass moves over a cooler, denser air mass. This type of inversion occurs in the vicinity of warm fronts, and also in areas of oceanic upwelling such as along the California coast. With sufficient humidity in the cooler layer, fog is typically present below the inversion cap. An inversion is also produced whenever radiation from the surface of the earth exceeds the amount of radiation received from the sun, which commonly occurs at night, or during the winter when the angle of the sun is very low in the sky. This effect is virtually confined to land regions as the ocean retains heat far longer. In the polar regions during winter, inversions are nearly always present over land.
That bit about relative IR rates is the key bit, from my point of view.
The Weather Channel also pointed out that the conditions needed were:
1) Clear sky. (i.e. no cloud layer blocking IR).
2) Still air. (i.e. no turbulent processes mixing the air and a lack of convective processes).
3) Dry air. (i.e. the water vapor content had to be taken out of the air for the IR to be free to leave).
So what does that LEAVE in the air? CO2.
Now think about this for a minute. If you have ANY of: Convection, barometric driven mixing, clouds, water vapor, water droplets; then IR does not dominate. With them all removed, and with the CO2 left in place, we have the full “CO2 Forcing” in effect (but unobscured by other drivers).
And what did we get? A New All Time Record Low.
I’d like to turn this into a whole lot more, but to me it’s clear and done at this point and any “more” is “less” clear.
CO2 is completely swamped by ANY of [ convection, wind, water vapor, clouds / water drops ] and when seen acting on its own can do nothing to prevent record lows from IR radiation from the surface.
There are sidebars and sidelights, but the crux of it is just that. CO2 is a wimp, and can be ignored. Water kicks sand in its face and clouds pee in its beer while the wind gives it a wedgie.
Sidebar on timing:
Look at the daily cycles. The IR cooling process happens in less than a day. From the 20th to the 21st things plunge. Why did it not happen on the 12th to 13th? Because IR was busy being beat up by the other processes. And when they are out of the way? Overnight a plunge to “way cold” that leaves CO2 “speechless”.
This means that the IR process is measured in HOURS, not days, weeks, months, and certainly not “30 year trends”. It’s over and done in HOURS. Trying to measure it with an annual average is folly of the worst sort. Trying to do so when there is clear evidence that it is irrelevant in the context of water and wind is lunacy. Doing it while completely ignoring clouds, humidity, and winds, as the “Annual Global Average Temperature” does is a bastard cross of folly with lunacy. “Just say no.”
Sidebar on Water and Wind
The Weather Channel put up two graphics. I don’t know if they were “typical” or actual data from the location, and I can only describe them here (i.e. I don’t have links… yet…)
One showed ‘normal conditions’ with it -40 F at altitude and something like -8 F at the surface, the other showed the inversion with it being -43 F at the surface (last night) and something like -15 F at 5000 feet. They then went into the above referenced discussion of the importance of ‘still air’ and low humidity to allow radiative cooling of the surface.
This made one thing very clear to me: Much of the “surface temperature” we measure is in fact measuring how much “vertical mixing” has happened (or not). We can get 30 F range based on how much vertical mix is going on? And nobody is taking that into account in the “Global Average Temperature”?
Where are the data on vertical mixing rates globally? Do we even have a clue how they change over time? Over 60 year PDO cycles? We’ve got 3 orders of magnitude “more there there” in the vertical mixing range than in the 1/100 C variations they are panicked over in “Global Warming” and it is being ignored?
Now look at that daily data again. Yes, there is wind moving things down from Canada, but it’s not the lateral displacement that is dominant here, it’s the vertical displacement. The lateral is taking several days to work, the vertical is much faster. There are “microbursts” that can down an airliner (over 2000 fpm downdrafts) and the distance we are talking about is 5000 feet. I make that 2.5 minutes time scale.
I’ve noted for a couple of years now that ever since the sun went quiet, the vertical atmospheric ‘thickness’ got compressed to thinner, and the PDO flipped: that the winds were more “bursty” and with more “vertical component” (in comments on various threads, many at WUWT). Now I think we have “why it matters”. Just ask the folks in Frostbite Falls…
Now, as that thinner colder layer gets colder (as has happened up North) we get more water vapor turned into ice crystals (all that snow on the ground as well as the ice in noctilucent clouds) and with more GCR (cosmic rays) making more condensation, if it’s more COLD condensation as ice, we get that “clear cold dry” air.
Conclusion
So, in the end, it’s all about what happens to the water, what happens to the wind, and what drives the clouds.
And even just ONE clear, dry, cold night with CO2 doing all it can but resulting in a record low EVER for that location pretty much says there is not a thing of importance being done by CO2. That even just one day away is drastically different says that the CO2 is not the “driver” here, it isn’t even in the passenger seat…