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Answers and explanations to Weather Quiz #1
Stop! Have you already taken Weather Quiz #1? If not, you really ought to take the test first. Answers and longwinded (pun intended) explanations follow below.
Answers and explanations to quiz #1:
1. A
The phrase “dog days” refers to Sirius, also known as the Dog Star, in the constellation Canis Major. The ancient Egyptians believed that this bright star added to the Sun’s heat, creating the hot, humid “dog days” of August. So dog days are hot, unlike another common expression, “three dog night,” which refers to cold. In the days before electric blankets, the family pets would often sleep atop the covers, helping everyone stay warm. If you needed three dogs to keep warm enough, that indicated a very cold night.
2. D
Don’t feel too bad if you picked C, 900 degrees Fahrenheit, because temperatures do reach that high on Venus. That answer is technically correct, but the best answer is still D. Nearly any kind of thermometer would be broken due to the crushing atmospheric pressure of our sister planet, especially after a 24-hour exposure. A capsule dropped by the Soviet spacecraft Venera 4 was crushed like a tin can as it descended through the thick clouds of Venus in 1967. Here on Earth, we’re much more comfortable with our average atmospheric pressure of 14.7 pounds per square inch. Venus’ atmospheric pressure is 90 times greater.
3. B
This is a bit of a trick question, due to the way it’s phrased. Remember Buy Ballot’s Law: If you stand with your back to the wind, high pressure is to your right and low pressure to your left. Therefore, if you stand facing the wind, high pressure is to your left.
4. A
Sunny weather is good weather, and good weather means high pressure. High pressure often moves in after the passing of a cold front, meaning the weather could start out on the cool side. When the jet stream loops to the north, it’s called a “ridge.”
5. B
An inch of snow in the course of 8 hours isn’t all that much. Also, when the weather changes from snow to mixed precipitation or freezing rain, that’s a sign of warmer air moving in. Light but long-lasting precipitation, as described in the question, is a sign of a warm front going by. With a warm front, the wind direction is most likely southwest. (A cold front would most likely bring wind from the northwest.)
6. B
Bees stay close to their hives before a storm because they require polarized light to navigate. Ice crystals in cirrostratus clouds on the leading edge of a storm destroy the polarization. In fact, beekeepers report that honey production is decreased during especially cloudy summers.
7. C
The mesosphere is the coldest layer of the atmosphere. The temperature decreases with altitude in the troposphere, but the absorption of ultraviolet rays by the ozone layer causes the temperature to rise in the stratosphere. Then in the mesosphere, 30 to 50 miles high, the temperature again decreases.
8. A
The temperature at which water vapor in an air mass will condense. If the air temperature and the dew point are the same, then relative humidity is 100 percent and fog will appear. For example, if the air temperature is 60 degrees and the dew point is 55, then cooling the air to 55 degrees will cause the water vapor it contains to condense and form a cloud or fog.
9. B
Friction at ground level slows down the wind a slight degree, weakening the Coriolis effect in the process.
10. D
There’s really no statistical support for the old folk saying, “Cows lie down before a rain.” As a predictor of weather, this is one example of folklore not being very helpful. Most cows seem to lie down whenever they please.
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