Smithsonian miscellaneous collections . .80 19. 0 3- 17 8 17-7 IO 5 20. 7S 19. 52 12 14 10. 7 10. 1 16 1-43 i8 i-34 7-9 1. 26 33-21 20 7-5 1. 20 7-1 Assume the radius of action of these cyclones to be about 200 andthat at this distance the absolute pressure is 76omm. The pressureb0 at the center is then in the first cyclone 72 and in the , and the increase of the pressure at the center is the same time that t
Smithsonian miscellaneous collections . .80 19. 0 3- 17 8 17-7 IO 5 20. 7S 19. 52 12 14 10. 7 10. 1 16 1-43 i8 i-34 7-9 1. 26 33-21 20 7-5 1. 20 7-1 Assume the radius of action of these cyclones to be about 200 andthat at this distance the absolute pressure is 76omm. The pressureb0 at the center is then in the first cyclone 72 and in the , and the increase of the pressure at the center is the same time that the maximum velocity has diminished imfrom to Adding b0 to b — b0 we shall find the pressure band consequently we calculate the increase of pressure at each dis-tance r. Assuming that the change has taken place in 4 hours, wefind the hourly variation d0 by dividing the increments by 4 asfollows; r do r So r So r do o° 6° io° 16° 2 7 12 18 0. o5 4° 0. 5o 8 14 20 FIG. 39 By constructing a curve repre-senting d0 = f (r) we easily deter-mine the distance r for successivevalues of d0 and can constructthe curve of equal variation (see %• 39)- (2) Moving cyclone with pressure constant at its center. When the pressure at the mov-ing center remains constant, thevariation of the pressure at anyfixed station is determined by equa-tion (4) of §30 and we have d = G W cos y MOVEMENTS OF ATMOSPHERE GULDBERG AND MOHN 223 Assume that W, the velocity of propagation of the center, is con-stant. For the value y = 71/2 we have d = o, that is to say, thecurve of no variation is a straight line that passes through the center,and is perpendicular to the direction of propagation of the center. Assuming y = o and y = n, and also G = GQ we obtain the maxi-mum value of d, which consequently falls at two points at the dis-tance r0 from the center along the trajectory of the cyclone. The curves of equal variation are dete
Size: 1483px × 1685px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsm, bookcentury1800, bookdecade1860, booksubjectscience
