Homework Questions for Chapter 15 - Hurricanes

Consult Syllabus for Due Date

Questions 1 and 2 will be turned in for a grade.

Follow the Problem solving steps discussed in class

1. The transport of mass of air through a given area can be expressed as r*V*A where r is the density of air, V is the velocity, and A is the area through which it is moving.

(a) What are the units of mass transport?

(b)  Calculate the vertical mass transport within the eye wall of a hurricane. Assume that the density is 1 kg m-3 and the vertical velocity is 3 ms-1. Also assume that the eye wall is cylindrical in shape with an inner radius of 20 km and an outer radius of 40 km.  Draw a picture of this meteorological situation.

(c)   If the net vertical mass transport in a hurricane is zero (i.e., upward mass transport = downward mass transport), is the upward motion in the hurricane eye wall of greater or lesser magnitude than the sinking motion (subsidence) on the outskirts of the hurricane?  Assume that the subsidence is occurring in an area of a cylinder where the inner radius is 100 km and the outer radius is 200 km.

2.  (a) With the aid of a diagram, show that the winds must flow clockwise around the hurricane center in the southern hemisphere.  Make sure to plot ALL relevant forces.

(b)  Assuming conservation of angular momentum, what will be the resulting tangential velocity at 25 km from the hurricane center if the tangential winds 100 km from the center are 5 ms-1?

3. Why are hurricanes more apt to form in October than in May?

4. Would the winds of a hurricane decrease more quickly as the storm moves over cooler water or over warmer land? Explain.

5. Suppose in the North Atlantic, an eastward-moving ocean vessel is directly in the path of a westward-moving hurricane. What would be the ship's wisest course - to veer to the north of the storm or to the south of the storm?

6. You are in Darwin, Australia (on the north shore), and a hurricane approaches from the north. Where would the highest storm surge be, to the east or west? Explain.

7. Occasionally when a hurricane moves inland, it will encounter a mountain range. Describe what will happen when this occurs. What will happen to the hurricane's intensity? What will cause the most damage (winds, storm surge, flooding)? Why?

8. Are the hurricane winds more likely in gradient wind balance or cyclostrophic wind balance? Explain.

9. A hurricane just off the coast of northern Florida is moving northeastward, parallel to the eastern seaboard. Suppose that you live in North Carolina along the coast:

a. With the aid of a diagram, explain how will the surface winds in your area change direction as the hurricane's center passes due east of you.

b. If the hurricane passes east of you, the strongest winds would most likely be blowing form which direction? Explain.

10.  What if the average number of hurricanes tripled.  How would the heat and moisture transport by hurricanes change the global circulation, if at all?

EXTRA CREDIT: Estimate the amount of energy produced by a hurricane in one day by latent heat release by condensation.  Compare it with estimated electrical usage throughout the US in one year.  (Make sure to document data sources)