Info

The source term on the right-hand side indicates whether the substance in question is created or lost, e.g. by phase changes or chemical reactions. SA will, in general, depend on all the state variables of the atmosphere, the air velocity and the mixing ratios for other constituents. In an approximate manner, the source term may be taken to depend only on the average values of its parameters (Wilson and Matthews, 1971),

The ideal gas approximation to the equation of state for the air reads, in averaged form,

where = 280 m2 s 2 K 1 up to a height z of about 90 km, above which level the molecular weight drops quickly. Eventually, a correction depending on humidity may be incorporated into (2.50).

The temperature is often replaced by a variable called the potential temperature, defined by

Oct.- March

Oct.- March

Figure 2.105. Distribution of seasonal (October-March) and longitudinal average of temperature T and potential temperature 9 for the Northern Hemisphere (based on Lorenz, 1967).

Figure 2.105. Distribution of seasonal (October-March) and longitudinal average of temperature T and potential temperature 9 for the Northern Hemisphere (based on Lorenz, 1967).

Was this article helpful?

0 0

Post a comment