Geology 1347 Meteorology

Transcription

1 Geology 1347 Meteorology Exam 1 Review 1. Carbon dioxide enters the atmosphere: a. mainly through the decay of vegetation b. volcanic eruptions c. exhalations of animal life d. burning of fossil fuels (coal, oil, and natural gas) The removal of CO 2 from the atmosphere takes place during photosynthesis. 2. The primary source of oxygen in the earth s atmosphere during the past 500 million years appears to be photosynthesis. 3. Because air near the earth s surface is compressed, air density normally decreases rapidly with height in the lower level and then more slowly as one moves farther away from the surface. 4. The ozone hole in the atmosphere occurs over Antarctica during September and October. 5. The greenhouse gasses are: a. carbon dioxide b. water vapor c. methane d. nitrous oxide e. chlorofluorocarbons (CFCs)

2 6. Wind is the horizontal movement of air. The wind direction is the direction from which the wind is blowing. 7. Pressure is defined as force per area. The force is then pressure times area. 8. The largest storms in the atmosphere are middle-latitude cyclonic storms (extratropical cyclones) which may be 2,000 km (1,450 miles) in diameter. The next size storm is the hurricane. The diameter of this storm is around 800 km (500 miles). The thunderstorm is the next size storm followed by tornadoes. 9. In the northern hemisphere winds blow clockwise and outward from the center of a high, and counterclockwise and inward toward the center of a low. 10. The atmosphere can be divided into layers based on its composition. Below the thermosphere, the composition of the air is fairly uniform (78% nitrogen, 21% oxygen) by turbulent mixing. This lower, well-mixed region is called the homosphere. The region from the base of the thermosphere to the top of the atmosphere is called the heterosphere. 11. The Venusian atmosphere is main composed of carbon dioxide (95%) and minor amounts of water vapor and nitrogen. This thick dense atmosphere produces a surface air pressure of around 90,000 mb. This thick atmosphere produces a strong greenhouse effect, with surface temperatures around 900 F. The atmosphere of Mars, like that of Venus, is mostly carbon dioxide. Unlike Venus, the Martian atmosphere is thin, and heat escapes from the surface rapidly. The surface temperatures on Mars are around -76 F. Because of this thin cold atmosphere, there is no liquid water on Mars and virtually no clouds. The average surface air pressure on Mars is around 7 mb. 12. Other names for tornados are twisters or cyclones. 13. Weather relates to the condition of the atmosphere at any particular time and place. Climate, however, represents the accumulation of daily and seasonal weather events over a long period of time.

3 14. Venus and Mars have atmospheres composed mainly of carbon dioxide. Jupiter s atmosphere is mainly hydrogen and helium, with minor amounts of methane, and ammonia. Earth s atmosphere is mainly nitrogen and oxygen. 15. The energy transferred from the sun to the earth is called radiant energy or radiation. These waves are called electromagnetic waves. This radiation is characterized according to wavelength. As the wavelength decreases, the energy carried per wave increases. The order of waves from longest to shortest is: microwaves, infrared waves, visible light, ultraviolet waves, and X rays. 16. Heat is energy in the process of being transferred from one object to another because of a temperature difference between them. 17. Objects that have a high temperature emit energy at a greater rate than objects at a lower temperature. Thus, as the temperature of an object increases, more total radiation is emitted each second. 18. The atmospheric greenhouse effect raises the earth s average surface temperature. Without greenhouse gasses the earth s average surface temperature would be quite low.

4 19. The wavelengths that an object emits depend primarily on the object s temperature. The higher the temperature, the shorter the wavelengths of the emitted radiation. 20. In conduction heat is transferred by molecule-to-molecule contact. During convection heat is transferred by the mass movement of molecules because of a difference in density. Radiation is the transfer of heat or energy through a vacuum. Since the moon has no atmosphere, the moon s surface is cooled by radiation. 21. The atmospheric greenhouse effect occurs because water vapor, carbon dioxide, and other greenhouse gasses are selective absorbers of infrared radiation emitted by the earth. 22. Albedo is the percent of radiation returning from a given surface compared to the amount of radiation initially striking that surface. Albedo represents the reflectivity of the surface. The albedo of clouds is about 60% meaning that 60% of the incoming solar radiation is reflected by the clouds. 23. Cloudy, calm nights are often warmer than clear, calm nights because clouds strongly emit infrared radiation back to the earth s surface. 24. The greenhouse gasses are: a. carbon dioxide b. water vapor c. methane d. nitrous oxide e. chlorofluorocarbons (CFCs)

5 25. In the middle latitudes of the Northern Hemisphere on December 21, the sun rises in the southeast, reaches its highest point at noon, and sets in the southwest. 26. Seasons are regulated by the amount of solar energy received at the earth s surface. This amount is determined primarily by the angle at which sunlight strikes the surface, and by how long the sun shines on any latitude. 27. Both the ground and air above cool by radiating infrared energy called radiational cooling. At night the ground and air in contact with the ground cool more rapidly than the air a few meters higher. By early morning, the coldest air is found next to the ground, with slightly warmer air above. This increase in air temperature just above the ground is called a radiation inversion. This inversion forms mainly through radiational cooling of the surface. This radiation is infrared radiation emitted by the earth s surface. 28. High latitudes tend to lose more energy to space each year than they receive from the sun, while low latitudes tend to gain more energy during the course of a year than they lose. To compensate for these gains and losses of energy, winds in the atmosphere and currents in the oceans circulate warm air and water toward the poles, and cold air and water toward the equator. The transfer of heat energy by atmospheric and oceanic circulations prevents low latitudes from steadily becoming warmer and high latitudes from steadily growing colder. 29. In middle and high latitudes, large seasonal variations in the amount of sunlight reaching the earth s surface produce large temperature contrasts between winter and summer. Annual ranges are large, especially in the middle of a continent. Hence, the large annual range of temperatures is found in polar latitudes of a continent. 30. The daily variation in air temperature is controlled by incoming energy (primarily from the sun) and outgoing energy from the earth s surface. When incoming energy exceeds outgoing energy, the air temperature rises. When outgoing energy exceeds incoming energy, the air temperature falls.

6 31. Crops can be protected from low temperatures by: a. covering them with straw, cloth, or plastic sheeting b. installing orchard heaters which circulate the air by setting up convection currents c. using wind machines which mix the cold air at the ground with warmer air above d. using an orchard s sprinkling system which allows the water to freeze around the branches and buds. As long as the spraying continues, the latent heat given off as the water changes into ice- keeps the ice temperature at 32 F. 32. The earth is tilted on its axis as it revolves around the sun. The angle of tilt is 23 ½ from the perpendicular drawn to the plane of the earth s orbit. This tilt causes the seasons throughout the year. If the earth s axis were not tilted, the noonday sun would always be directly overhead at the equator and there would be 12 hours of daylight and 12 hours of darkness at each latitude every day of the year. With no tilt of the earth s axis one would expect in the middle latitudes of the Northern Hemisphere cooler summers and warmer winters than at present. 33. On a clear, calm night, the air near the surface can be much colder than the air above. The increase in air temperature with increasing height above the surface is called a radiation temperature inversion. 34. The largest diurnal range of temperature occurs on high deserts, where the air is often cloudfree, and there is less carbon dioxide and water vapor in the atmosphere to radiate much infrared energy back to the surface. 35. Meteorological data shows that summers in the Southern Hemisphere are cooler than summers in the Northern Hemisphere. This is the result of an increase of ocean area in the Southern Hemisphere from the Northern Hemisphere. The Southern Hemisphere has nearly 81% of the surface area covered by water whereas the Northern Hemisphere has 61% of its surface area covered by water.