Calculations With the above qualitative discussion in mind, some simple numerical values will be considered. The equation of motion for an ideal fluid of density p, horizontal velocity V, in a frame of reference fixed to earth ole is V=-=Vp+28 sin (Vxk), where Vp is horizontal pressure ascendent, vertical vector. (1) @ is earth's angular speed, ¢ is latitude, and k is local unit At the equator the last term vanishes and the problem becomes one-dimensional along the equator (x direction). Thus equation (1) becomes Dire du dt ap (2) ax By finding expressions for p and p as functions of t, and holding x fixed, the goal of computing u will be realized, An expression for the variation of pressure as a function of time and distance along the equator can be written as p-p,= (Ap) oy cos ( x - xX) a t-t, Ut am ) ; (3) where Py is mean pressure, (AP) ax is peak pressure difference, a is geocentric radius to level of interest, x- Xx) is in 7a units east along the equator, b is time for one period (24 hours = 8.64 x10 4 sec). Since pressure and density change in phase with each other, a similar expression results for density: (- ~ Xo P = + Po (AP) vax cos t - 2) + a 27 . b 4 (4) Integration of equation (2) after substitution from (3) and (4) yields t x - x (Ap) max sin us : a t - to + 20 b x - XO hy Po + (Ap) vax cos( a dt. (5) t - tS + 27 b } Evaluating the right-hand side of (5) with boundary conditions that u = 0 at x = Xj t=t,, where P-P u max =P 7 PS = Zero: = b(Ap) max 27a(Ap ) na In p (is) p. + (Ap) a x Now (6) can be evaluated with use of some typical numbers b= 8.64 x 10° sec + a= 7,.0x 10° em - Ap = 3.85 x 10 2 wb (dynes/cm ), Ap = 3,90 x io 38 em/em* > 1 p, = 4.70 x io '® gm/om> a x . (6)