Tuesday, March 13, 2012

For Climate, All the World's a Stage

I have submitted this posting as a comment on the tallbloke site:

adolfogiurfa (March 12, 1:58 am) wrote, "There is nothing of the above without the SUN…"

tallbloke responded, "...Hans plays safe and treats solar output as constant in his thesis presentation."

This exchange is a fleeting but vital clue to a fundamental point, which I have tried to focus upon, as a result of my Venus/Earth temperatures comparison (which basically says, the global mean temperature at any given pressure level in the atmosphere depends, above all else, only on the Sun, not on atmospheric carbon dioxide, nor--most surprisingly to everyone--even on the planetary albedo). The fundamental point is, what IS climate and what comes BEFORE it? For example, those who speak of the "complexity" of the "climate system", or label the system "chaotic", are simply not focusing upon the larger picture, which is: The stage, upon which "weather" and "climate" play their parts. My small but definitive contribution to climate science has been to sweep the stage of those players and their never-ending entertainment, and show its bare simplicity. I am not a climate scientist, nor even a meteorologist, but all those with theories of climate have largely confused non-specialists--and too often themselves--with too many details, given without a sense of their proper scale in the overall picture; in other words, they mistake the forest for the trees, or they fail to frame the system, but rather consider it a roiling mass of incoherent (not well understood) processes, always on the verge of being an out of control, or "runaway", climate.

My Venus/Earth comparison--which compared Earth's Standard Atmosphere model, developed over many years of painstaking observations, with the Venus temperature- and pressure-profiles obtained on a single day (October 5, 1991)--should first and foremost be understood as confirming the Standard Atmosphere as the true, unchanging stage upon which weather and climate (or weather/climate) play their parts (or its various parts).

The atmosphere is subject to heat from the Sun and from the independently warmed surface, and the understanding I have so far gleaned is two-fold:

1) Solar forcing is primary, and vertical--it sets the stage.
2) Surface forcing is secondary, and horizontal--it drives the weather/climate.

In other words:

1) Direct heat from the Sun (in the infrared portion of the solar spectrum) fundamentally warms the atmosphere, and gravity parcels that heat, in accordance with the hydrostatic pressure distribution, into the observed vertical temperature lapse rate structure. The Sun essentially warms every body exposed to its rays, separately--you, me, the surface of the planet, and every level of the atmosphere.

2) Heat from the warmed surface (mostly ocean, on the Earth) diffuses horizontally, as it tries to escape toward space along the governing temperature lapse rate, the temperature gradient. That diffusion is huge (and the surface heating is uneven, primarily latitudinally), producing the winds, whose detailed causes range from the rotation of the planet down to local topography and land/ocean boundaries. My Venus/Earth comparison should tell everyone that the heat from the surface (which is dependent upon the albedo) has no effect upon the fundamental level of warming of the atmosphere. It basically acts to generate horizontal forces to spread the heat retained by the Earth, from one day to the next, around the planet. Those horizontal forces, nevertheless, are nicely balanced with the vertical flow along the lapse rate, so that vertical heat transport predominates at the equator and poles, while horizontal flow predominates in between, and an impressively coherent, general circulation is maintained (the details of which, I have not studied, and know little).

This is not a theory, but only the merest sketch, connecting the stage conditions, as exposed by my Venus/Earth comparison, with the resulting grand play of weather/climate.

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