Transcript Lecture 13, Steady State Analysis

Steady State Analysis
AOSC 620
Fall 2015
Definition: Steady State – the condition where the concentration of a
substance is unchanging in time. This implies that the production and loss
rates are equal.
A system in thermodynamic equilibrium is necessarily in steady state , but a
system in steady state is not necessarily in thermodynamic equilibrium.
More interesting is the occurrence of quasi-steady state – where the overall
rate of change is small compared with the production and loss terms. This
applies to many atmospheric and oceanic species of importance to climate.
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The first theoretical derivation of quasi-steady state appears in Global
Biogeochemical Cycles in an article by Cicerone and Oremland (1988).
Consider a gas in the atmosphere with a mixing ratio that varies in time and
space:
[ ] = f(x, y, z, t)
And the molecular number density is
M = f((x, y, z, t).
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R3 = R2
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[O]ss = j1[NO2]/k2[O2][M]
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We’ll see where this
comes from later.
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