SCIN 137 AMU week 6 lesson Hurricanes and also Air Pollution Introduction to Meteorology American Military university
- Lesson Overview
This week we cover Hurricanes and also Air Pollution. While these are two completely separate topics, each has tremendous impacts on human settlements and activities. Air pollution is in always the news these days, and many of you may remember the controversies surrounding the Olympic Games in China due to the poor quality of air there. Air pollution is something we can control, since man-made pollution is the vast majority of what ails us – we’re our own worst enemies when it comes to air pollution!
Students will be able to:LO-39. Explain why hurricanes form and dissipate. LO-40. Explain why hurricanes move along somewhat predictable paths. LO-41. Compare tropical cyclones with mid-latitude cyclones. LO-42. Explain why the atmosphere can become polluted. LO-43. Identify the various types and sources for pollution. LO-44. Discuss why some locations are more prone to pollution than others.
The following activities and assessments need to be completed this week:
- Read Barry and Chorley: Chapter 11
- Week 6 Lesson
- Week 6 Forum
- Week 6 Lab
- Week 6 Quiz
- COMET Modules (Optional):
- Anticipating Hazardous Weather and Community Risk, 2nd Edition
- Supporting Military Emergency Response During Hazardous Releases
- Tropical weather is very different from the weather in the middle latitudes. The tropics give birth to hurricanes that have done much damage and caused much loss of life. Why do they form? What distinguishes a tropical storm from a hurricane? Why are they more likely to hit the east coast than the west? You will find the answers to all these questions in this lesson. The second part of the lesson examines air pollution – the types, sources, and contributing factors. Topics to be covered include:
- Tropical weather
- Hurricane formation
- Naming hurricanes and tropical storms
- Hurricane damage
- Types and sources of air pollution
- The Air Quality Index (AQI)
- Acid deposition
The tropics is a band from 23 ½ degrees north of the equator to 23 ½ degrees south of the equator. The weather in the tropics differs greatly from that of other latitudes in several ways:
- There is very little difference in temperature year-round.
- The sun’s angle is nearly overhead throughout the year, so this is the warmest region on earth.
- The humidity level is generally high.
At sea level, pressure variations are small so forecasters use streamlines, maps that depict windflow, more than pressure maps with isobars. The first map shows just the wind direction and speed and is provided to help you read the streamlines on the second map. This is an area of the South China Sea during a cyclone, as indicated on the map. Notice how the wind direction north of the cyclone is opposite to the wind direction south of the cyclone. You know by now that temperature differences are very important in weather. The temperature difference between the poles and the tropics is greatest in the summer. The heat stored by the end of summer in tropical oceans fuels the development of hurricanes.
A hurricane is an organized group of thunderstorms centered around a very low pressure center (a severe tropical cyclone) and has winds of at least 64 knots or 74 mph. They are known as hurricanes in the western Atlantic, typhoons in the North Pacific, as tropical cyclones in Australia, and as cyclones in India. The international standard name is tropical cyclone for all such storms that form in the tropics, but we will call them hurricanes in this lesson. Before a storm becomes a hurricane, it is a less violent tropical storm.
Tropical storms and hurricanes are given unique names in alphabetical order each year. Names are recycled every six years, so the names of the 2020 storms will be the names of the 2026 storms. However, the names of the epic hurricanes like Katrina are retired and no longer appear in the lists. You will likely never see a hurricane named Xavier because the letters Q, U, X, Y, and Z are not used for the official list. Some years the tropical storms and hurricanes stop with the Ks, but in 2005 the entire list was used before the season was over. They named the additional six storms after Greek letters: Alpha, Beta, Gamma, Delta, Epsilon, Zeta (NOAA, n.d.).
If you blow across the surface of your coffee in its cup, you can disturb the coffee, maybe even blow some of it out of the cup. Hurricane winds also push the ocean along since the wind is stronger on one side.
Suppose a hurricane is headed west for the coast of Florida. The most powerful wind is usually on its northern side, at the surface. The winds heading west that push a hurricane on its path increase the winds moving west and oppose the winds moving east. In this situation, the most damage from wind and the highest storm surge usually occurs just north of the eye. So this intense wind just north of the eye at the surface of the ocean pushes water east. The winds can also create high waves (up to 15 m or 49 ft high) that bring more water and damage. The low pressure eye causes the ocean level to rise (up to one meter or 3 ft). The lift of the ocean surface together with pushing the water and the waves creates a storm surge, a rise of several meters above normal ocean levels, flooding coastal land. This picture shows the destruction of the Bolivar Peninsula in Texas from Hurricane Ike’s storm surge in 2009.
If the hurricane changes directions, the direction of the storm surge changes with it, so the hurricane brings a storm surge in whatever direction it is headed.
When do you think air pollution first became a problem? Air pollution has been with us since the first fire. It is “a mixture of natural and man-made substances in the air we breathe” (NIH, 2016). Smoke in London was so great a problem that King Edward I banned the burning of coal in London (Committee, 1871, p. 4):
“In 1306 Parliament petitioned the King Edward I to prohibit the burning of coal in London, on the grounds of its being an intolerable nuisance. It was prohibited, and wood ordered to be used.”
However, despite the law, coal continue to be burned. In 1661, John Graunt blamed many deaths on the burning of coal by factories and homes (Graunt, 1661). The five-day Big Smoke of 1952 caused the deaths of at least 4000 people. Legislation has greatly improved the air in modern London, but it is estimated that 380 premature deaths are caused each year by air pollution (Davis, et al. 2002).
The Industrial Revolution in the U.S. greatly increased air pollution