Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The zonal component of the wind increases linearly from u = 0 at the ground to u

ID: 802090 • Letter: T

Question

The zonal component of the wind increases linearly from u = 0 at the ground to u = 10 m s^-1 at a height of one kilometer. In the same region, the vertical velocity increases linearly from w = 0 at some point to w = 1 m s^-1 at a distance one kilometer to the north, (a) Compute the rate of increase in the vertical relative vorticity. Your solution should have units of s^-2, (b) At this rate, how long will it take for air of initially zero relative vertical vorticity to reach a value 10^-3 s^-1? Report your answer in hours to one significant figure.

Explanation / Answer

a vertical relative vorticity=dv/dx-du/dy

du= 10-0=10 ms-1

vertical distance y=1km=1000m

du/dy=10/1000=0.01s-1

dv=1-0=1ms-1

x=1km=1000m

Now dv/dx=1/1000=0.001s-1

Rate of increase in vertical vorticity=dv/dx-du/dy

=0.001-0.01=0.009s-1

b. Final relative vorticity=10-3 s-1

Initial relative vorticity=0

Rate of change in vorticity=0.009s-1

Now, Rate of change= relative vertical vorticity/time

10^-3s-1/time

0.009=10^-3/time

time=10^-3/0.009

=0.11s

To convert into hour

1 hour=3600 sec

therefore 0.11/3600

=3.05*10^-5 hour