Dynamical Equilibrium Theory on the Fundamental States of the Earth's Atmosphere

[摘要] The old problems, why an almost constant lapse-rate exists in the troposphere and why exists the so-called stratosphere, are not yet solved. Nowadays, it is generally believed that these fundamental states of the earth's atmosphere can be considered as a result of radiative equilibrium. But in this paper it will be proved that these fundamental natures of the atmosphere can also be described as a dynamical equilibrium of the fluid rotating with the earti. Using the spherical polar coordinates (r, θ, ψ, ), which are independent of the earth's rotation, the state of dynamical equilibrium is described by the following three equations of motion:--where the solutions T, P are assumed to be independent of φ, and homogeneous for all longitudes. U is the rotational flow velocity of air and its functional form is determined from the third equation. If we assume a solid rotation of the atmosphere with the earth, U becomes ωrrsin θ, ω being the angular velocity of the earth.From the remaining two equations T is solved and the so-called lapse rate of temperature is described as follows:by making use of the boundary conditions at the earth's surface: at the pole T=TP and at the equator T=TE.Using the Hann's table of TE and TP, we get the following results:For the stratosphere, to which the above discussion can be applied, we get Tropopause can be described to be discontinuousiu, temperature and continuous in pressure.The pressure distribution may be Known from equation (2), which shows low pressure at the pole and high pressure at the equator.And so the westerly and high-pressure zone of middle latitudes are not to be described as a result of the fundamental flow U. These phenomena can be explained by the second fundamental flow, which is to be considered as a deviation from U and determined from (3).Putting u=U+u, we get u∞r2sinθ•cosθ. And the pressure deviation becomes P∞rsinθ.This shows low pressure at the equator and high pressure at the pole.Thus combining two pressure systems, one resulting from the fundamental flow U and the other a deviation from this, we can understand that the so-called high pressure belt of middle latitudes is also a result of dynamical equilibrium.

[学科分类] 大气科学