Homework 7. Due Monday, May 25th 1998 Section
1. Because of dust and pollution, the concentration of condensation nuclei over the land is usually tens of times higher than it is over the Pacific ocean. Let's compare two stratocumulus cloud decks; one in the middle of the Pacific, and another over Seattle. Suppose each cloud contains approximately the same amount of liquid water.
a) Which cloud deck has more water droplets? Why?
b) Which cloud deck has smaller water droplets? Why?
c) Which cloud deck is more likely to drizzle? Why?
2. The sun is getting low in the sky near the western horizon as sunset approaches. There are showers around you as well as breaks in the clouds, and you see a rainbow in the sky. Which direction (from you) is the rainbow (east, west, north, or south)? As the sun sinks toward the horizon, does the rainbow appear taller or shorter in the sky? How do you know this? You may draw a diagram to answer this question if it helps.
3. a. Explain why the depletion of stratospheric ozone occurs more during spring than summer
b. Explain why the depletion of stratospheric ozone occurs more during spring than winter
c. Keeping in mind that the CFC's are chemically inert gases in the troposphere, explain how it is possible for them to be a source of a chemically active form of chlorine in the stratosphere but not in the troposphere. Why does this happen only at the same altitude of ozone? Why does it happen only at polar latitudes.
d. Explain why the ozone hole is so much bigger over the South Pole than over the North Pole
4. Draw and label arrows for the pressure gradient force, the Coriolis force, and friction (if friction is present) for parcels A & B, making sure that the relative length of the arrows reflects the relative strength of each force. Assume that neither parcel is accelerating (i.e. the forces are exactly balanced), and that the parcels are in the Southern Hemisphere.
(OVER)
5. a) Sketch a 500 mb ridge and trough wave pattern (located in the Northern Hemisphere). Pick two points on the wave. Draw and label the wind direction (W), the Coriolis (CF) and pressure gradient (PGF) forces at those points such that the flow is in geostrophic balance. Use a single arrow
(---->) for the forces and a double arrow (===>) for the wind direction. (Remember to specify the length of the arrows so that the forces balance.)
b) Draw a circular high pressure system at the surface (located in the Northern Hemisphere). Pick two points on the sketch. Draw and label the Coriolis (CF), pressure gradient (PGF), and frictional (FF) forces. Use a single arrow (---->) for forces and a double arrow (===>) for wind direction. (Remember to specify the length of the arrows so that the forces balance.)
6. a) You are stationed in Berlin during the height of the cold war. Your unit launches a missile at Moscow, and then realizes that they forgot to correct for the Coriolis force! (They should have taken Atmospheric Sciences 101.) How far off the target and in what direction will your missile be deflected by the Coriolis force? In order to solve this part you may assume that :
i) Moscow is directly east of Berlin 1700 km.
ii) Your missile is fired directly at Moscow with a speed of 100 m/s and maintains its eastward speed of 100 m/s for the whole trip.
iii) The missile is deflected by the Coriolis force an average of 9.882m horizontally for every second it is in the air.
b) The cold war ends and you decide to remain in Berlin as a professional baseball player. One night you are pitching, and, just as you let go of the first throw, you realize you forgot to correct for the Coriolis force! How far and in what direction is the baseball deflected by the Coriolis Force? You may assume:
i) You throw the ball directly south at a speed of 25 m/s.
ii) The ball travels for 0.8 seconds before reaching the catcher.
iii) During its flight, the baseball is deflected by the Coriolis force an average of 4.659 x 10-5 m horizontally for every meter it travels south.
c) The length of cyclones and anticyclones is about 1500 km. Why do people consider the effect of the Coriolis force when analyzing the weather but not when throwing a ball?