Mid-term Exam - October 13, 1997

1. What are the three forces that act on horizontal air motions? Which one or ones appear because of the rotation of the Earth?
   Pressure gradient, Coriolis, and friction forces. The Coriolis force appears because of the rotation of the Earth.

2. Give two examples of greenhouse gases and list their principal anthropogenic sources.
   Carbon Dioxide, from burning of fossil fuels; methane, from cows and waist degradation; water vapor, from evaporation.

3. Who was Svante Arrhenius and what was his contribution to the theories of climate change?
   He was a Swedish chemist who lived during the past century. He was the first to estimate the surface temperature change due to a doubling of carbon dioxide.

4. Give two examples of air pollutants and list their principal sources.
   Nitrogen oxides, carbon monoxide, and sulfur dioxide come from automobiles. Surface ozone is produced photochemical reactions, nitrogen oxides from decomposing organic materials.

5. What is "acid rain"? Give two examples its impact on the environment.
   Acid rain is precipitation which pH is 5.7 or lower. It impacts the environment through acidification of lakes and rivers, destruction of plant leaves.

6. What is the classification for tropical cyclones and what is it based on?
   Tropical cyclones are classified according to wind speed into: tropical depression, tropical storm, and hurricane.

7. What aspects of a hurricane are the most dangerous to people and cause most of the damage?
   The most dangerous aspect of a hurricane is the storm surge and the flooding due to very large amounts of precipitation.

8. Do scientist believe that the frequency and intensity of hurricanes will increase with global warming? Why?
   No, because scientist do not know who all the factors known to affect tropical cyclones or hurricanes (wind shear, lapse rate, etc) will change with global warming.

9. Where in the continental United States are severe thunderstorms most likely to occur? Where are they least likely?
   Most likely in Florida and along the coast of the Gulf of Mexico, least likely along the west coast (California).

10. What kind of meteorological instrumentation is currently used to detect and forecast tornado occurrences? What do these instruments indicate?
    Doppler radar is used because it can detect sudden changes in wind speed and indicate regions where the air "spins".

11. Explain the difference between a passive and active remote sensing device, and give an example of each.
    A passive remote sensing device, such as the weather satellite, observes (or measures) naturally occurring radiation; active remote sensing devices, such as the weather radar, actively send "pulses" which are reflected by the object or objects being observed (or measured).

12. What does the shape and appearance of clouds tell us about them? What atmospheric ingredients are needed to form clouds?
    It tells us what the clouds are form of (water or ice crystals, for example) and can sometimes tell us the weather to come. The main ingredients are water vapor, and some kind of lifting mechanism.