ATS 350 Midterm Exam 1 2025

ATS 350 Midterm Exam 1 2025 The most abundant gas in earth's atmosphere is what? - Correct Ans-Nitrogen If you're standing on top of Long's Peak, about what percentage of air do you have to breathe compared to someone at sea level? - Correct Ans-60% because the person at sea level has 100%. A typical value of atmospheric pressure in Los Angeles (elevation 46 meters or 151 ft above sea level) would be what? - Correct Ans-1000 millibars Imagine that the temperature in Fort Collins is equal to that in Greeley. Fort Collins is about 300 feet higher in elevation than Greeley. Which of the follow is true? - Correct Ans-Both the pressure and density at Fort Collins are lower than at Greeley. Which layer of the atmosphere do we live in? - Correct Ans-Troposphere In the stratosphere, the air temperature generally what? - Correct Ans-Increases with increasing height The fact that the air on higher floors of a building tends to be warmer than on lower floors is primarily a result of what? - Correct Ans-Convection The set of instruments attached to a weather balloon and launched twice per day to measure the atmosphere is known as a what? - Correct Ans-Radiosonde If you doubled the temperature of an object, how many times stronger is the radiation? - Correct Ans-16 (if you double the temperature, there's 16 times more radiation, because the Stefan-Boltzmann law states that the intensity of radiation is proportional to temperature to the 4th power, so 2^4= 16. If, by some process, the sun got much hotter, the wavelength of the radiation it emitted would be? - Correct Ans-Shorter The gases in the atmosphere that are primarily responsible for absorbing outgoing longwave radiation are? - Correct Ans-Water vapor and carbon dioxide Latent heat gets released into the environment when these processes occur. - Correct Ans-Condensation and freezing (and deposition) The tropics (low latitudes) receive more radiation than the poles (high latitudes). The main reason the tropics don't keep getting hotter and the poles getting colder is due to what? - Correct Ans-Cyclones and ocean currents transport heat towards the poles ATS 350 ATS 350 Why do we have seasons? - Correct Ans-The earth is tilted on its axis (and earth rotates around the sun, so the areas tilted away/ toward the sun change as the earth orbits) If Earth's tilt decreased (became less tilted), what would we expect in the mid-latitudes? - Correct Ans-Cooler summers and warmer winters (lesser range of temperatures) On June 21, which of these latitudes has the fewest hours of sunlight? - Correct Ans-60 degrees South (the furthest degree south is darkest because it is the summer solstice In Fort Collins, the warmest month (in the long-term average) is? - Correct Ans-July On June 21 (summer solstice), Fairbanks, Alaska sees almost 22 hours of daylight, whereas Fort Collins sees just over 15 hours. Yet the normal high at Fairbanks is 70 degrees F and at Fort Collins 82 degrees F. Why is the location with shorter days warmer? - Correct Ans-The sun is more directly overhead at Fort Collins so the sunlight is more intense than at the lower angle in Fairbanks. The flashlight example. Consider two cities at the same latitude: one in the middle of a continent, and one on an island in the ocean. Which would you expect to have a greater annual range of temperature? - Correct Ans-City in the middle of a continent because a body of water acts as a temperature stabilizer near coastal regions. On average, which hemisphere has the greater annual range of temperature? - Correct Ans-Northern hemisphere because there are more land masses that can change temperature more efficiently than large slow-to-heat oceans. At which of these locations would you expect to observe the greatest daily range in temperature? - Correct Ans-At the ground (on land) because water has a much greater heat capacity than land, so it's harder to heat or cool the ocean surface. Also the ground radiates heat upward more efficiently than air (which radiates both up and down), so the surface heats and cools faster than the air above. A strong radiation inversion is most likely to develop under which of these conditions? - Correct Ans-Clear, calm night because clouds absorb heat and radiate downward, so it tends to stay warmer at the ground. Also the winds mix up the air so that the temperature is more uniform with height at low level (less chance of inversion). Is the air heavier on a humid day? - Correct Ans-No, because of the molecular weight of H2O is less than the molecular weight of dry air constituents. Then why does it feel so uncomfortable on a humid day? - Correct Ans-Because it is harder for evaporative cooling to happen on your skin when the outside air is wetter. On a dry day, evaporative cooling can remove the heat. ATS 350 ATS 350 On a calm, clear night the dewpoint temperature of the air near the surface ____ while the relative humidity of the air near the surface ____. - Correct Ans-Remains about the same/increase. Remember the temperature is decreasing as night falls. Consider the typical conditions in Tucson, Arizona, and Duluth, Minnesota, in January. Which of these describes how the dewpoint and relative humidity compare between these two spots? - Correct Ans-Tucson has higher dewpoint but a lower relative humidity than Duluth. Dewpoint depends on temperature and current water vapor. Tucson generally has a higher temperature than Duluth in January. It has more actual water vapor than Duluth, so it has a higher dewpoint. But the amount of water vapor possible (at saturation) is much more in a Tucson winter than a Duluth winter. Relative Humidity is the actual water vapor in the air divided by the possible water vapor in the air at saturation. So it's like this for example: For a parcel in each location Tucson = 20/100 particles of H2O whereas Duluth = 6/10 particles of H2O. Relative humidity is the actual amount of water vapor in the air divided by the amount that would be in the air at saturation. If the amount of water vapor in the air isn't changing, you still change RH by what? - Correct Ans-Warming or cooling the air. Saturation vapor pressure is a function of temperature only, so warming or cooling the air will change the saturation point and thus the Relative humidity. Why does it get so uncomfortably dry indoors during Colorado winters? - Correct Ans Because the dewpoints are the same (low in both places), but the inside air is much warmer than the outside air. So the Relative Humidity inside is very low, but outside it is very high. What is actually happening when someone says, "the fog burns off'? - Correct Ans-Sun heats the air near the fog, temperature goes above the dewpoint and the fog erodes. How does ozone affect the temperature profile in the stratosphere? - Correct Ans Ozone warms stratosphere How does pressure change with height? What is the average pressure at the surface? - Correct Ans-Pressure decreases with height. Average pressure is 1000 millibars at sea level. What's the relationship between mb, hPa, Pa? - Correct Ans-1mb = 1hPa= 100 Pa Which substance requires more energy to change its temperature: dry air or water? Which changes temperature at a quicker rate? - Correct Ans-Water requires more energy to change temperature because it has higher capacity. Dry air changes quicker. What happens to a parcel of dry air if it is forced to rise over a mountain? The temperature cools to the dewpoint temperature, and what does that mean? - Correct Ans-A dry parcel of air will rise, expand and cool.. If the temperature cools to dewpoint temperature, a cloud will form and possible precipitate. ATS 350 ATS 350 What are the relationships between energy, temperature, and wavelength? - Correct Ans-E=T^4 energy is proportional to T^4 wavelength is 1/T. In radiative balance terms, explain why the Earth's surface heats during the day and cools at night. - Correct Ans-Surplus of radiation during the day and a deficit of radiation at night. Is the annual range of temperatures larger at the poles or the tropics? - Correct Ans Poles have larger annual range of temperature due to tilt and intensity of sun's rays as well as the orbit. The ocean also helps regulate temperature, less range in tropics. How is the radiative balance affected by water vapor (like fog on the ground) during the night? - Correct Ans-Water vapor from fog keeps the night warmer. If the sun's angle increased, what would happen to the summers and winters? - Correct Ans-Summers would get hotter and longer days. Winters would become colder and darker. In what season is the Northern Hemisphere tilted away from the sun? - Correct Ans Winter Is the earth-to-sun distance responsible for the season? When is the earth actually closest to the sun? - Correct Ans-No. January What does a temperature inversion look like (what happens to the temperature as you go up? Is this absolutely unstable or absolutely stable? - Correct Ans-Temperature increases with height. Stable What is the definition of lapse rate? - Correct Ans-How much temperature decreases with height (always positive) What is the MALR value? What is DALR value? - Correct Ans-Moist adiabatic lapse rate 6 degree C/km Dry adiabatic lapse rate 10 degrees C/km Where is the greatest variation in daily temperatures? On the ground or higher up? - Correct Ans-Greater variation on ground (larger heat capacity) At night, is it warmer at the surface, or somewhat above the surface? - Correct Ans Waver above the surface because the ground radiation heat goes up. Would wind cause the nighttime temperature to be higher or lower? - Correct Ans Higher because less variation with height ATS 350 ATS 350 What happens if you set a glass of water in a saturated cloud? Will the water level go down or up, or do nothing? - Correct Ans-It will do nothing; the cloud is saturated (if it wasn't the water would decrease) What 2 things happen when air sinks? When air rises? - Correct Ans-Warms and compresses when sinking ; cools and expands when rising Why does the low temperature occur before sunrise, and not at midnight? - Correct Ans-Sunrise is when the earth has the least net radiation Is the Gulf Stream warm or cold near Florida? - Correct Ans-Warm Give an example of how a parcel can have high RH, but low water vapor. Give an example of how a parcel can have low RH and high water vapor. - Correct Ans-High RH Temp=10 degrees C Td= 10 degrees C (low water vapor content; high RH) Low RH Temp t=100 degrees C Td= 70 degrees C (more water vapor) If you heat up an air parcel, but you don't change the water vapor in it, what happens to its dewpoint? What happens to its RH? - Correct Ans-Stays same; decreases If you add a gas to the atmosphere that absorbs shortwave, what does that mean for the surface of earth? - Correct Ans-Less radiation and cooler temperatures If a parcel saturates at a high altitude, then you bring it back down to the surface, will its final dewpoint be larger or smaller than its original dewpoint? - Correct Ans-Dewpoint is smaller due to raining If you take a parcel over a mountain and it saturates and rains out on its journey, does that mean its final temperature will be more or less than its original? - Correct Ans-Final temperature will be greater than its original due to condensation loss