MHO, the sun has caused the collapse of the Thermosphere described in this article. That is a major driving event to our present cold phase (and the very strong AO that’s pushing all that cold air out into the UK and Europe).
I suspect, but have not yet found confirmation, that this is a “continuum event” and has impacts in the Mesophere as well, and that it is our largely lacking understanding of these things that causes CO2 to be meaningless.
NASA-funded researchers are monitoring a big event in our planet’s atmosphere. High above Earth’s surface where the atmosphere meets space, a rarefied layer of gas called “the thermosphere” recently collapsed and now is rebounding again.
“This is the biggest contraction of the thermosphere in at least 43 years,” says John Emmert of the Naval Research Lab, lead author of a paper announcing the finding in the June 19th issue of the Geophysical Research Letters (GRL). “It’s a Space Age record.”
The collapse happened during the deep solar minimum of 2008-2009—a fact which comes as little surprise to researchers. The thermosphere always cools and contracts when solar activity is low. In this case, however, the magnitude of the collapse was two to three times greater than low solar activity could explain.
“Something is going on that we do not understand,” says Emmert.
Well, at least they are recognizing that we really don’t know what all is going on in the air. Now if they can just connect the dots to that large variable star and the very large swings in the particular spectrum it emmits … and that maybe we don’t know all the subtile things that it does in the different air layers…
The thermosphere ranges in altitude from 90 km to 600+ km. It is a realm of meteors, auroras and satellites, which skim through the thermosphere as they circle Earth. It is also where solar radiation makes first contact with our planet. The thermosphere intercepts extreme ultraviolet (EUV) photons from the sun before they can reach the ground. When solar activity is high, solar EUV warms the thermosphere, causing it to puff up like a marshmallow held over a camp fire. (This heating can raise temperatures as high as 1400 K—hence the name thermosphere.) When solar activity is low, the opposite happens.
I do note that this article feels compelled to drag in CO2 as an agent, but does admit it would be a minor one and mostly we just don’t know what the heck is going on. Oh, and in this case CO2 is magically cooling instead of warming things…
One possible explanation is carbon dioxide (CO2).
When carbon dioxide gets into the thermosphere, it acts as a coolant, shedding heat via infrared radiation. It is widely-known that CO2 levels have been increasing in Earth’s atmosphere. Extra CO2 in the thermosphere could have magnified the cooling action of solar minimum.
Yet somehow it did not act as a ‘coolant’ during the rest of the solar cycle? CO2, the magical gas….
“But the numbers don’t quite add up,” says Emmert. “Even when we take CO2 into account using our best understanding of how it operates as a coolant, we cannot fully explain the thermosphere’s collapse.”
Well, at least he’s got clue…
According to Emmert and colleagues, low solar EUV accounts for about 30% of the collapse. Extra CO2 accounts for at least another 10%. That leaves as much as 60% unaccounted for.
In their GRL paper, the authors acknowledge that the situation is complicated. There’s more to it than just solar EUV and terrestrial CO2. For instance, trends in global climate could alter the composition of the thermosphere, changing its thermal properties and the way it responds to external stimuli. The overall sensitivity of the thermosphere to solar radiation could actually be increasing.
“The density anomalies,” they wrote, “may signify that an as-yet-unidentified climatological tipping point involving energy balance and chemistry feedbacks has been reached.”
IMHO, one of the best moments in this article. The recognize that they are just making stuff up and it may have some explanatory value… or not. Bravo!
Important clues may be found in the way the thermosphere rebounds. Solar minimum is now coming to an end, EUV radiation is on the rise, and the thermosphere is puffing up again. Exactly how the recovery proceeds could unravel the contributions of solar vs. terrestrial sources.
“We will continue to monitor the situation,” says Emmert.
For more information see Emmert, J. T., J. L. Lean, and J. M. Picone (2010), Record-low thermospheric density during the 2008 solar minimum, Geophys. Res. Lett., 37, L12102.
So it looks to me like we really don’t know how the sun drives the atmosphere.
And they are really just hoping that this Major Minima is coming to an end. It isn’t. It’s just hitting a tiny speed bump on the way to “It’s dead Jim”…
Vukcevic thinks he has ‘found clue’ about this. “The magentosphere is involved” would be my interpretation:
Original Image from http://www.vukcevic.talktalk.net/IonSph.htm