Download Investigation 12A and 12B

Investigation 12A: Hurricanes
The purpose of Investigation 12A is to describe the track taken by a hurricane that occurred in
the western North Atlantic Ocean and to indicate the probable position of highest storm surge when a
hurricane takes landfall. Figures 1, 2, and 3 along with Tables 1 and 2 were used to answer questions 117. Figures 4 and 5 were used to answer questions 18-25.
A hurricane is a tropical cyclonic storm system that has maximum sustained surface wind speeds
of 119 km per hour of higher. Hurricanes are low-pressure centered rotating circulations. Hurricanes
form over the warm tropical ocean and gain energy from heat released when water condenses in the
storm system. Hurricane are one third the size of a typical cyclone of the middle latitudes. It forms a
uniform mass of warm and humid air that has no fronts or frontal weather. Hurricanes can be
detrimental because they cause flooding, strong winds, heavy rain and tornados. Hurricanes that affect
eastern North America are usually formed in the Gulf of Mexico, the Caribbean Sea, or in the West
African coast. Hurricanes initially are steered westward by trade winds, but sometimes curve northward
or northeastward. Where the hurricane curves will determine what part of the United States it will
effect. Not all hurricanes move this way. Hurricanes have been reported to move in circles or figure
eights.
Hurricane Katrina greatly affected the United States. It intensified to a category 5 storm with
winds of 173 mph. It weakened to a category 3 storm when it hit land near the Louisiana-Mississippi
border. The storm was very large and brought upon major flooding in the area. Because of this, students
would probably be interested in learning about its path. Figures 1, 2, and 3 are different tropical storm
advisories from the NHC Katrina Graphic Archives. I would have my students study these maps in order
to answer the questions. They can get a better understanding of the path that Katrina took and why it
was so detrimental for so many people. Students can also take a look at the North Atlantic Storm Tracks
in order to better understand the hurricane systems that affect us every day.
Investigation 12B: Hurricane Wind Speeds and Pressure Changes
The purpose of Investigation 12B is to describe the relationship between the maximum wind
speeds and the central pressure in a hurricane, categorize the damage potential of a hurricane based on
wind speeds, and explain how wind speeds in hurricanes are affected by landfall. Figure 1 and Table 1
are used to answer questions 1-9. The wind speeds on Table 1 were used to plot the winds speeds every
six hours onto Figure 1. These plotted points were connected with straight lines, and this line was used
to answer questions. A coin was centered on the Figure 2. The coin was moved northeastward and
counterclockwise along hurricane Wilma’s track to simulate the surface wind directions of the traveling
hurricane. A vertical line was drawn on Figure 3 across the wind and pressure panels at 24 October 7
a.m. Figures 2 and 3 were used to answer questions 9-21.
Hurricanes are intense tropical cyclones that are created over warm ocean waters. They gain
momentum through energy transported to the atmosphere from the ocean through evaporation and
condensation of water vapor within the hurricane and cumuliform clouds. Latent heat is released as the
water vapor condenses, warming air that expands and rises as more humid air flows upward from the
ocean. Air sinks within the storms center and warms. The less dense air in the center of the storm or eye
of the storm exerts a lower pressure compared to the surrounding atmosphere. This produces intense
inward horizontal pressure gradients that result in strong winds. This continues until the energy supply is
disrupted which weakens the system. This can happen if the hurricane travels over colder waters or an
encounter with land.
Directly following studying Hurricane Katrina, I would have students study the path of Hurricane
Wilma in Figures 1, 2, and 3. Students can analyze the graphs to study water levels and wind speeds at
certain times. Students can see where Hurricane Wilma went and how it affected Miami and Naples. As
always, being able to read and interpret graphs is a large part of the mathematics curriculum and I
believe that studying hurricanes is a great way to get students engaged in the learning.