Lab 3 - Cyclone Cycles
100 points - This lab has been adapted from an activity developed through the SAGE project at the University of Arizona.
Cyclones are large masses of air that circulate around a region of low pressure in the atmosphere. If cyclones gather enough energy, they become hurricanes, one of the most destructive weather phenomena on earth. In this activity you will investigate cyclone patterns and their causes.
Directions
1. Before you begin this actvity, make sure that you have completed the reading on the lesson.
2. You will need to use a plugin program called Quicktime to view several movies associated with this lab. If you do not have a copy of this freeware program, download Quicktime now, and follow the directions to install it.
3. Read through this assignment once, then follow the steps below.
Part I, Hurricane Luis
Open the Quicktime movie of hurricane Luis. This will open in a new browser window. You may switch back and forth between this browser window and Quicktime movie. Close the new window when you are done.
Luis swept through the Atlantic ocean August 27 to September 11, 1995. Luis was a category 4 hurricane (using the Saffir-Simpson Hurricane damage potential scale), with winds reaching speeds of 225 mph, and a lowest central pressure of 935 mb. See a color satellite picture of LUIS.
Before you play the movie, orient yourself: you are looking at the Atlantic ocean, with coastlines and states outlined in yellow. Play the movie several times, observing Luis's path and the motion of the hurricane itself. You can step through the movie frame-by-frame using the right and left arrow buttons on the Quicktime navigation bar.
Questions Answer the following on a separate sheet of paper in complete sentences.
1. (5 points) Is Luis's path clockwise or counter clockwise? What phenomena accounts for this?
2. (5 points) Did the winds in Luis spin clockwise or counter clockwise? If you are having trouble observing this in the movie, consider what you know about cyclones (are they low pressure or high pressure zones?).
3. (15 points) The north coast of Australia is very prone to cyclones. Do the winds in cyclones that occur along the north coast of Australia blow clockwise or counter clockwise? What phenomenon accounts for this? 4. (20 points) Why is it that the west coast of the United States never has problems with cyclones, while cyclones annually cause significant destruction along the east coast of the United States?
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Part II, Cyclone Cycles
Recall from homework 2 that insolation is not distributed evenly over the surface of the earth. Furthermore, water heats up and cools down more slowly than land due to its greater heat capacity. In the second part of this exercise, you will explore the relationship between the sea surface temperature and the formation of cyclones.
Temperature Conversions
In America, we are accustomed to talking about temperatures in Farenheit rather than Celsius. You probably have a pretty good feel about how 'warm' 80° F is, or how 'cold' 50° F. In science we use Celsius to talk about temperatures, so before we go any further, let's get a feeling for what 'hot' and 'cold' really mean in the Celsius scale. Remember to do a reality check with your calculations: based on the temperature map in the GIS (see below), is your result physically reasonable? |
Conversion Formula:
°F = (°C*1.8)+(32)
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Use the conversion formulas to the left to calculate the following:
| 10°C = _____ |
20°C = _____ |
30°C = _____ |
40°C = _____ |
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Questions (you do not have to answer these in complete sentences):
5. (20 points) List the following Fahrenheit temperatures in the Celsius scale: 10°C, 20°C, 30°C, 40°C Round your answers to two decimal places.
Open up your second browser window: the
HTML GIS viewer (this will open a new browser window). Recall from week 1 that GIS (Geographic Information Systems) is a suite of software products that allow geographers to view and manipulate spatial data. In this case, we will be using a simulated GIS to look at the relationship between four datasets: Sea surface temperature in February, sea surface temperature in August, occurrence of cyclones in February, and occurrence of cyclones in August. You can turn on various map layers by clicking in the boxes next to the layer name. By clicking in multiple boxes, you can view multiple layers at once.
Use your HTML GIS viewer to answer the following questions:
Questions (Answer in complete sentences):
6. (10 points) How is the tilt of the earth related to the pattern of ocean heating? Give specific examples.
7. (10 points) What is the optimal temperature for cyclone formation? Why do you think that this is the case?
8. (15 points) If global warming is taking place, and (hypothetically) ocean temperatures were to increase by 3°C world-wide within 100 years, what effect would this have on the frequency (how often) and latitude of cyclones? Cite specific examples based on the data you have gathered with the HTML GIS.
See the Solution and Grading Rubric for this Lab Assignment.
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