Accession Number : AD0014966


Title :   A MATHEMATICAL MODEL OF ZONALLY UNIFORM ATMOSPHERIC CIRCULATION


Corporate Author : BROWN UNIV PROVIDENCE RI


Personal Author(s) : Fofonoff, N P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/014966.pdf


Report Date : Jun 1953


Pagination or Media Count : 26


Abstract : A model of a simplified atmosphere is described which permits the analytical study of heat-exchange processes. The equations of mass and momentum conservation were the basis for the model. The atmosphere was assumed to be an almost incompressible fluid covering a smooth earth to a very small mean depth in comparison with the earth's mean radius. The steady-state motion of the atmosphere was assumed to be driven by a known density distribution, and the density variations were assumed to be small enough so that their effect on the fluid motion was given by a variable gravitational force. Frictional forces were assumed to arise from Reynolds stresses and were included by the introduction of a constant, isotropic kinematic eddy viscosity. Non-linear terms were neglected and the motion was assumed to be independent of longitude. The coordinates of a point in the atmosphere were assumed to be adequately approximated by a spherical coordinate system in which gravitational forces acted in the radial direction. The model determines the distribution of zonal and meridional velocity components corresponding to a given density field and representing a balance of pressure-gradient, Coriolis, gravitational, and frictional forces. A numerical example is presented where the distribution of the horizontal density gradient was chosen to be antisymmetric about the equator, to vanish at the poles, and to be proportional to a fifth-degree polynomial in the phi coordinate. The thermodynamics of the model were not considered.


Descriptors :   *UPPER ATMOSPHERE , *ATMOSPHERE MODELS , STEADY STATE , EQUATORIAL REGIONS , DENSITY , DISTRIBUTION , THERMODYNAMICS , MASS , MOTION , EDDIES(FLUID MECHANICS) , ATMOSPHERIC MOTION , DEPTH , NONLINEAR SYSTEMS , ISOTROPISM , BALANCE , GRAVITY , CONSERVATION , VISCOSITY , SIMPLIFICATION , INCOMPRESSIBILITY , GRADIENTS , MOMENTUM TRANSFER , LONGITUDE , GRAVITATIONAL FIELDS , KINEMATICS , PRESSURE GRADIENTS


Subject Categories : Atmospheric Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE