A hurricane is a strong tropical cyclone that measures several hundred miles in diameter and has 74+ mph winds. It is an area of intense low atmospheric pressure.

Hurricanes have two main parts. The first is the eye of the hurricane, which is a calm area in the center of the storm. Usually, the eye of a hurricane measures about 20 miles in diameter, and has very few clouds. The second part is the wall of clouds that surrounds the calm eye. This is where the hurricane's strongest winds and heaviest rain occur.

Hurricanes are born over warm, tropical oceans. The top 50 meters of the ocean surface needs to be 26.5^o C. The air above the ocean must be cooler than the water temperature, allowing thunderstorms to form. Hurricanes are fueled by water vapor that is pushed up from the warm ocean surface, so they can last longer and sometimes move much further over water than over land. The combination of heat and moisture, along with the right wind conditions, can create a hurricane.

Hurricanes are enormous, and they can range in size from 300-600 miles wide and about 10 miles high. They typically have a lifespan of about 10 days. The wind speed of a hurricane is 75 miles per hour or more. Between 40 mph and 74 mph winds, the storm is called a tropical storm.

The fierce winds and rains cause damage to natural areas such as mangrove swamps, estuaries as well as causing major erosion in coastal areas. Also hurricanes damage manmade structures such as housing, buildings, and infrastructure.

Hurricanes play an important part in maintaining marine habitats.

Marine animals can withstand the natural effects of these storms, but they are not adapted to withstand

discharge of boat fuel and oil that can continue for weeks, damage caused by the movement of lobster and crab traps, pollutants from runoff, introduction of non-native plant species. Historically man has been a primary contributor to the dispersal of non-native plant species; however, a hurricane event can quickly disperse the non-native plant species with the high speed winds.

The Puerto Rican Parrot inhabits vegetated sand runs of clear creeks. Hurricane Opal improved this endangered species partly because fallen logs from the storm provided more cover. Also, more eddies were formed so the fish could hide from the severe weather.

Sea Turtles live only in forests of very old pine trees. Foraging habitat is provided in pine and pine hardwood stands 3O years old or older with foraging preference for pine trees 1O inches or larger in diameter. Almost all the nesting trees were destroyed in Hurricane Andrew. The species was already endangered due to deforestation of these older trees.

The Red-Headed Duck are bottom dwellers and they filter feed. Phytoplankton had a major bloom due to runoff and the sediment layer smothered many organisms. Turbidity, nutrient loading, and dissolved organic carbon had a negative effect on the organisms. Pollutants from sunken boats and from runoff were deadly.

Humans living and working in coastal areas cause these problems. Humans also affect the survival of these animals by diminishing large portions of different species. Many of the animals who are most affected by hurricanes are endangered species already.

Hurricanes are natural, but the affected species populations must be healthy in order to withstand these mighty storms. Our responsibility is to ensure they are allowed the best chance possible.

- Tornado tube connectors and 2 2-liter bottles per connector

(found at many toy stores)

• Posters with newspaper clippings and facts
• Typing paper
• Construction paper
• Markers
• Drawing compass
• Scissors (1 per student)
• Transparent tape
• Thread (3" per student)
• Hot water
• Large pyrex glass bowls (3)
• 2 balloons and an extra 2 liter bottle

• The patterns for the mini hurricanes should be traced on the tissue paper before class.
• The thread should be cut into 12" sections.
• The water should be heated up at the beginning of class.
• Enough tornado tubes should be made for every few students to get one.
• Prepare a timeline puzzle using these steps:

1. Hot air rises over tropical oceans near the equator.
2. Thunderclouds form
3. Winds begin circling around the eye of the storm.
4. Storm travels.
5. Circling winds increase to 74 MPH or more.
6. If hurricane reaches the shore, land is flooded by the storm surge.
7. Hurricane fades gradually as it moves inland.

• Prepare a poster with facts from The Magic School Bus Inside a Hurricane.

Weather

• We all experience it every day.
• In certain extreme cases, weather can cause severe damage.

• Hurricanes: Hurricane Andrew caused around $20 billion of damage

Hurricanes

Can somebody please describe what a hurricane looks like?

(Bring out and demonstrate the tornado tube for a warm-up activity)

• This is what a hurricane looks like. Does it remind you of any other type of storm?

• Hurricanes are actually very similar to tornados and cyclones, but they occur over water.
• The eye of the hurricane is the calmest part of the storm.

• These areas usually have cool air and warmer water.

• Let’s do an experiment to see. (call up a volunteer) This bottle is filled with cool air. By placing the bottle in a bath of hot water, we can heat up the air to see what happens.

• The balloon inflated. Why?
• Hot air expands, which means the air molecules move further apart. This makes the hot air less dense or "lighter" than the cool air, so it rises up and "floats" on the cooler air.

• We can do an experiment to see how it moves. (Pass out mini-hurricanes and hot water to every two students.)
• The spiral represents the clouds in a hurricane. Put it above the hot water and see what happens. You can use the cold water to change the temperature of the water.
• Predict what will happen with different water temperatures.
• (Discuss everyone’s observations…does hotter water make it spin faster?)
• (Turn over hurricane poster and discuss the movement of air)

• No, before the wind speed reaches 74 MPH (and after it reaches 40 MPH) it is called a tropical storm. Many of these never reach land.

• (Explain this description on the poster)
• We have a short video clip that shows this process very well (show video)

• (sum up the ingredients of a hurricane.)

Now we understand how hurricanes work, but why do the do so much damage?

• (Describe the storm surge on the poster.)

- To sum up, let’s see how much you all understand about hurricanes.

• (Call up a volunteer to put the correct words with the definitions. Discuss.)
• (Call up another volunteer to put together the puzzle. Discuss.

Give at least two questions you could ask the students after the experiment and/or formulate a conclusion that ties the experiment together with larger concepts.

1st question: From your experiments, what do you need to create a hurricane?

2nd question: (If there is time) Pick your favorite marine animal. What might happen to that animal in a hurricane?

3rd question: What effects might humans have on how well animals survive hurricanes?

4th question: What are some steps that we can take to reduce the human impact on the survival of the environment.

Conclusion

Go around the group and have the students explain why the hurricane models work. Does it work like that in the real world?