onsdag 19 maj 2010

Your Second Climate Model

The thermodynamics of global climate is described by the Navier-Stokes equations, for compressible flow of air in the atmosphere, and incompressible variable-density flow of water in the oceans.

For the atmosphere there are two possible basic hydrostatic equilibrium states depending on a vertical coordinate, which can be taken as a starting points for climate dynamics:
  • (i) constant temperature (T = 261 K, zero lapse rate)
  • (ii) isentropic with linear temperature profile (T = 302 K, constant lapse rate 10 C/km),
as shown in On Atmospheric Circulation. Fitting these solutions to data as in On Maximum Entropy Profiles by Verley and Gerkema, Journal of the Atmospheric Sciences, Vol 41, 2004,
pp 931-937, one obtains the ground temperatures given above, with (i) too low with too small lapse rate and (ii) too high with too large lapse rate, as compared to the observed T = 288 with lapse rate 6 C/km.

Real atmosphere dynamics involves turbulent vertical convection, which can be viewed as increasing (i) and decreasing (ii): Rising hot air cools by expansion, and turbulent dissipation heats. This directly connects to the computational simulation of the Joule experiment in The Secret of Thermodynamics in BodyandSoul Mathematical Simulation Technology, chapter 166.

We learn that the observed ground temperature of 288 K and the observed lapse rate
of about 6 C/km, are compatible with a flow model without "heat-trapping greenhouse gases".

The same argument explains the high temperature on the surface of Venus as a primary effect of high pressure thermodynamics and not greenhouse gases. Compare The Reference Frame: Venus with the crucial observation:
  • The cause of most of the temperature gradients is mechanical (lapse rate) rather than infrared-radiative.
This gives perspective on the role of greenhouse gases in an atmosphere. You may compare
the above model with the climate alarmism basic model: Stefan-Boltzmann's Radiation Law.
Which model do you think best describes the physics?

2 kommentarer:

  1. This Venus thing has been beaten to death at Chris Colose's site.


    The adiabatic lapse rate is indeed a bound. An isothermal atmosphere does not provide the opposite bound. The real atmosphere has well-marked persistent zones of positive and negative lapse rate, see e.g. http://www.kowoma.de/en/gps/additional/atmosphere.htm .

    A near-linear lapse rate is in no way guaranteed, and such a presumption is begging the question. All we know for sure is that entropy increases upward.

    What this has to do with the Joule experiment or its simulation escapes me.

  2. The Joule exp concerns temperature drop under expansion and thus connects to temp drop of hot rising air under expansion. Agree?