## Monday, October 24, 2011

### Simple Versus Too Simple

Making the complex simple to understand is the goal of science, any discipline really. That goal often requires compromises where one portion of the overall concept is attempted to be explained by analogy to a commonly understood concept.

Physics uses many basic analogies, Carnot Engines, Equilibrium and adiabatic processes, as foundations even though none may ever exist. They are convenient models of perfection for comparison.
In atmospheric physics, the dry adiabatic lapse rate, where temperature changes with pressure with no gain or loss to the system, is an example of an equilibrium state with prefect energy transfer, a Carnot engine. Perfection does not exist in nature, it can only be approached.

The dry adiabatic lapse rate in Earth’s atmosphere is the combination of the surface temperature, the composition of the gases in the atmosphere, the molecular weight of the gases, the thermal properties of the gases, the gravitational constant and radiant energy interaction with the changing density and composition of gases compressed by gravity. A rather complicated process we on the surface take for granted.

If you are in favor of electrical analogies, the adiabatic lapse rate is an inductive load with a steady state current. Small changes in current are dampen by properties of the inductor and rapid change produces huge changes in the potential energy or electromotive force realized across the inductive load.

The electromotive force is provided not by a single source, but several, a conductive battery, a latent battery, a gravitational battery and a radiant battery are the more significant power sources.

The radiant battery is both solar and black body, with cells poorly designed for the task, but adequate in steady sate conditions. In steady state, the potential can be determined at different points in the atmospheric circuitry and the total accurately calculated from one connection to the next. i.e. if we know the voltage and current into a black box and the current and voltage out of that black box, we can determine to a point what circuitry is in the box. With more than one condition, we can better describe the inner circuitry.

The currents are in parallel from the electromotive sources at the surface, Fc, Fl, Fr, and F?, for conductive, latent, radiant and the question mark is ever present uncertainty. Each of the batteries providing these currents or fluxes, have cells, Fra, Frb, Frc …Frn, for example. The subscript letters can be individual wavelengths, associated energies, or combinations of wavelengths and energies that impact portions of the atmosphere.

This is the simplicity of the Kimoto equation, dF/dT=4(aFc+bFl+cFr+…F?)/T, which is derived from Stefan’s equation, Fi/Fo=alpha(Ti)^4/alpha(To)^4, or the change in energy flux of a body is proportional to the change in temperature of the body at initial temperature T. All the coefficients, a,b,..n, represent changes to the flux through the atmospheric inductor or impedance.

Proper use of this simple equation requires, proper consideration of the flux values and ever present uncertainty.