Abstract
§1. Introduction
The so-called equations of fluid motion show that the fluid particle is accelerated by pressure gradient, which is assumed to be a force exterior to the fluid system. But, in reality, the pressure gradient is not an “exterior” force, but is influenced by the fluid motion itself.
V. Bjerknes, famous theorem states that circulation is accelerated by baroclinic field. But, as mentioned just now, this statement must be supplemented by the idea that the baroclinic field may also grow as a result of circulation, because this theorem is introduced from the equations of motion.
The deformation or change of pressure (temperature, etc.) field is described analytically in the following section.
§2. Analysis of changing fields (Press., Temp., Pot. Temp., Density).
The motion of fluid particles is analysed, and equations of the changing field of f are introduced, f being any physical quantity. That is:-
and two other equations of y and z directions.
This is a well-known differential formula.
§3. -Equations of various changing fields.
When we take density (ρ) as f, this becomes as follows by using the equation of continuity:-
where_??_is the velocity vector.
When the fluid undergoes polytropic change, we get for pressure (P), temperature (T) and potential temperature (θ) fields:
§4. Equations of changing baroelinic fields.
The baroclinic field develops as a result o fluid motion.
§5. Vorticity and the baroclinic field -their growth.
This problem has been discussed by many authors. But many of them treat only equations of motion. In this paragraph it is shown that these problems must be discussed by using two systems of equations, one of which is of motion, the other of changing fields.
And as a result of this analysis, the following scheme of the genesis of vorticity and the baroclinic field has been obtaind for only a short time at initial growth.
