Why do daily pressure fluctuations occur, and where on Earth can you find significant daily fluctuations?
What will be the ideal response?
ANSWER: We might expect to see the surface pressure dropping as the air temperature rises, and vice versa. However, daily (diurnal) fluctuation of pressure actually appear to be due primarily to the absorption of solar energy by ozone in the upper atmosphere and by water vapor in the lower atmosphere. The warming and cooling of the air creates density oscillations known as thermal (or atmospheric) tides that show up as small pressure changes near Earth’s surface. A good example of daily pressure fluctuations can be observed in the tropics, where pressure rises and falls in a regular pattern twice a day. Maximum pressures occur around 10:00 A.M. and 10:00 P.M., minimum pressures near 4:00 A.M. and 4:00 P.M. The largest pressure difference, about 2.5 mb, occurs near the equator. It also shows up in higher latitudes, but with a much smaller amplitude.
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Which of the following sites near a volcano might be relatively less dangerous?
A) A site that is within the shelter provided by the volcano's central crater B) A site on a ridge as opposed to a site in a valley C) A site protected by steep slopes of the volcano D) A site where rocks have been weakened by hot volcanic fluids E) All of these are correct.
Why isn't dirt listed in the periodic table?
A. Elements like dirt and air are so common that there is no need to list them in the periodic table. B. Dirt IS listed in the periodic table but is not easily recognized because it is listed as one of the rare earths with its old scientific name, dysprosium, symbol Dy. C. The periodic table lists only elements made of one kind of material. Dirt is a mixture of elements and compounds. D. None of the above is true.
Why does an air parcel become cooler as it rises and expands?
A. The air pressure around the parcel increases as it rises. B. As molecules push outward to expand the parcel the parcel loses energy. C. Water vapour in the parcel evaporates as it rises. D. The density of the air parcel decreases as it rises.
If Earth was in a cooling trend, which process would most likely act as a positive feedback mechanism?
A) increasing the snow cover around Earth B) increasing the water vapor content of the air C) decreasing the amount of cloud cover around the globe D) increasing the carbon dioxide content of the air