Little Bubbles part 2 – Firn; The Great Equalizer

Continued from part 1…

Guest Post by Caleb Shaw

I will now tell you what I’ve learned, so you can subject it to your kindly WUWT peer- review. I’m fairly certain I’ve gotten some of it wrong, because it doesn’t entirely make sense.

For the purposes of this paper we will imagine a place where snow falls at a great rate, builds up and compacts swiftly, and turns to ice with little bubbles, in only sixty years.  We will begin sixty years ago, in the year 1951, on an icecap where the temperatures are always below freezing.

When snow first falls it is called, “Snow.”  I find this very relieving, because Climate Scientists have more words for snow than an Inuit.  Their official reason for this is to respect other culture’s words for “snow,” and to demonstrate political correctness, as in Climate Science that correctness is more important than the mathematical sort, and they are exceedingly respectful towards all cultures, except Yankees. (In fact I imagine their secret reason for creating the snow-jargon is to keep Yankee laymen like myself confused, hoping the confusion will keep us from butting in where we are not wanted.  It is almost as if they are saying, “Yankee go home,”  but two can play that game.  With the exception of the single word “firn,” I will only use Yankee lingo.)

The snow that fell in 1951 was dry, and around 95% air,  but wind whipped it around and it became the sort of packed powder that is around 90% air.  At this point the snow is 1951 snow, and the air is 1951 air.

As seasons pass this snow gets buried deeper and deeper by successive snowfalls, as temperatures never allow thawing.  As 1951 turns to 1961, and 1961 turns to 1971, the sheer weight of the snow overhead causes changes in the packed powder.  Despite the fact temperatures never rise above twenty below, the snow behaves as if it had thawed, and becomes “firn,”  which involves the snowflakes becoming crystals of ice too large to be called flakes.

As decades continue to pass and pressures build the firn becomes what Yankee call “gritty snow,” (like granulated sugar,) and then becomes “corn snow,” and finally becomes “candle ice.” Then, in the year 2011, with over 400 feet of snow overhead, we arrive at a momentous occasion, wherein the air in the ice, which once was able to move with some degree of freedom through the firn, is locked into little bubbles. Firn is firn no longer, and has stepped over the frontier and become ice.

I’m sure Climate Scientists have a word for this frontier, but I can only research so long before my computer freezes up, and therefore I’ll make up my own Yankee jargon,  and call the boundary between firn and ice, “The Firnopause.”

It is at the Firnopause that the formerly free air suffers the indignity of an icy chastity belt clamping about its freedom, forcing it to become what Climate Scientists call, “pristine.”  And pristine it must remain, eon after eon, until at long last a gallant Climate Scientist rides up and frees it from its deplorable condition. (Sorry about the purple prose. Unfortunately that is a prerequisite, in Climate Science.)

And that gallant Climate Scientist then discovers a remarkable thing.  As you remember, the snow originally fell in 1951, so the ice around the bubble dates from 1951.  However the air within the bubble dates from 2011. Somehow the air from 2011 has made its way down through over 400 feet of tightly packed snow, and all the air from 1951 has been booted out.

Accepting authority, I try to get my mind around this amazing natural phenomenon, and to think of what natural factors could have caused it to occur.

It can’t be the kinetic movement of air, for that higgiltypiggilty movement would not cause 1951 air to only move up, even as 2011 air only moves down. Even the most frenetic kinetic motion would create a mix of airs from all the years between 1951 and 2011, with air from 2011 the least likely to be down that deep.

It can’t be due to expansion and contraction of summer and winter air, because, once you move down ten feet  into the firn, temperatures remain constant, and air neither expands nor contracts.

The best solution involves the difference between a huge 950 mb winter storm and a huge 1040 mb winter high pressure area.  Before my computer froze I determined this was a difference between 13.778 psi and 15.084 psi. (I haven’t a clue what this means in terms of volume; the peer-review of WUWT will help me out, I’m sure.)  However, because I prefer math to be simple, I will state there is a ten percent difference in volume between  the same amount of air in a 950mb low and a 1040mb high.

This is a significant difference.  Stand by a cave with a large chamber and a small entrance as barometric pressures falls,  and you will feel a breeze blowing out.

A cave is actually a poor analogy for firn, for firn in effect has a large entrance which funnels down to smaller and smaller cracks and capillaries.  However, just to shut me up, assume that, as a 950mb low gives way to a 1040 mb high overhead, air actually can be inhaled 10% of the way down into the firn.

Big deal. That is only 40 feet, and leaves you with 360 feet to go, for 2011 air to be at the Firnopause in time to be clamped into little bubbles. Furthermore, as soon as the 1040 mb high starts to move off and pressures fall, the 2011 air gets exhaled out.

Obviously we need to discover a way to inhale the 2011 air down, and exhale all the pre-2011 gas out.  Fortunately Climate Science is much like undone homework; if you have no excuse you can always make one up.

Therefore, to be helpful, I have invented the concept of “grabacules.”  Grabacules are yet-to-be-discovered, gravity-activated, kinetic bonds on the sides of fresh air,  but worn off the sides of stale air.  Because they are gravity-activated, 2011 air slides freely downwards through the firn, but grabs onto the ice when any power tries to move it back up.  In essence 2011 air stands aside for pre-2011 air, (which lacks grabacules,) to pass, and then moves downwards again the next time downward forces come into play.  The 2011 air moves like an inchworm, moving foreword, grabbing, and moving foreword again.

Pretty cool theory, aye?  Isn’t Climate Science wonderful!?  (And if you think  that idea is good, you should have heard my excuses for undone homework. A breathless hush would fall in the classroom, as I arose to speak…)

The problem with my admittedly brilliant idea is that the inch-worm gets shorter and shorter.  Moving 10% of the way to your goal can never get you to your goal.  Up at the surface of the firn, a huge change in atmospheric pressure may shove the 2011 air 40 feet downwards,  but 100 feet from the firnopause the same change only moves the 2011 air 10 feet towards the goal, and 10 inches from the goal it only moves an inch towards its goal.

According to my layman’s calculations that is as far as the 2011 air gets, for by then it is 2012, the 2012 Air starts downwards, and the 2011 air, its grabacules all shot to heck, has to U-turn and start back upwards to make room for the 2012 air.

This leaves a space of nine inches the 2011 air never gets to.  This is a very important space, for it is this air which is actually is incorporated into the little bubbles.  If this air isn’t 2011 air,  what is it?

First we must have a name for this nine inches, just above the Firnopause, and I suggest it be called the Yankeeopause, (named after me, of course.)

It is in this nine inches which a factor so tiny it is unseen, up at the surface,  becomes glaringly apparent.  It is a factor I call “Spongeosis.”

We all know that, when you squeeze a sponge, water comes out.  The exact same thing happens when you squeeze snow, which is 95% air, and wind up with the Firnopause ice, which is at best 10 % air.  The difference is that with a sponge you squeeze out water, but when you squeeze snow you squeeze out air.  Where is that air to go?  Nowhere but up.

This very weak, nearly imperceptible flow is unseen at the surface, where changes in barometric pressure have veritable tides of air inhaling and exhaling through the firn,  but down in the quiet and still depths of the Yankeeopause, this flow is all there is.  Like the bow-wave of a boat, it moves just ahead of the freeze-up at the Firnopause, and consists of the very last bit of air squeezed from the snow.  It never holds air from above, and rather consists of a great many years worth of air all slowly pushed ahead like snow before a plow.  Some of the air may be centuries old,  and when a part of the Yankeeopause’s blended air gets left behind as a bubble in ice at the Firnopause,  the CO2 level in that bubble will not represent any particular year,  but rather an average.  All peaks and valleys in the CO2 record will be smoothed out.  The firn, in the end, has been a great equalizer.

And that is the end of my story, which I have told for your entertainment.  It flies in the face of the desire of Climate Science, which is to move 2011 air down to inclusion in tiny bubbles at the Firnopause.  However it’s my story, and I’m sticking to it.