Weak Pressure Gradient Approximation and Its Analytical Solutions

Nonlinear shallow - water solutions using the weak temperature gradient approximation

A form of the weak temperature gradient (WTG) approximation, in which the temperature tendency and advection terms are neglected in the temperature equation so that the equation reduces to a diagnostic balance between heating and vertical motion, is applied to a two-dimensional nonlinear shallow-water model with the heating (mass source) parameterized as a Newtonian relaxation on the temperatur...

The Hadley Circulation and the Weak Temperature Gradient Approximation

The weak temperature gradient (WTG) approximation is applied to simple shallow-water models of the Hadley circulation. While it is difficult to formally justify the use of the WTG approximation for this problem, the derived WTG solutions are shown to agree well with numerical solutions of the full equations and to converge to the traditional angular momentum conserving (AMC) solutions in the in...

Gradient Estimates for Weak Solutions of A-Harmonic Equations

Analytical Approximation to Solutions of Singularly Perturbed Boundary Value Problems

In this paper, a computational method is presented for solving a class of nonlinear singularly perturbed two-point boundary value problems with a boundary layer at the left of the underlying interval. First a zeroth order asymptotic expansion for the solution of the given singularly perturbed boundary value problem is constructed. Then the reduced terminal value problem is solved analytically u...

An analytical approximation for the MOID and its consequences

We give an analytical formulation for the approximation of the Minimum Orbital Intersection Distance (MOID) between two elliptical orbits, and we apply it to the case of the Earth and of an asteroid. With this formulation we are able to find an algorithm to compute the variance of the MOID for a given asteroid and we make the computation in the case of the asteroids whose orbit has been determi...