Hurricane Frequency and Intensity
In recent years more and more attention has been paid to the Earth's climate and how it is evolving. When studying hurricanes it is important to understand that, for a hurricane to grow, warm water is an absolute necessity. So if the Earth continues to warm, what does that mean for hurricanes and their intensity? Your job is to look at past hurricane data by researching the intensity and frequency of hurricanes using the Live Access Server and several Internet sites found in the Lesson Links section.
Grade Level: 9-12
Estimated Time for Completing Activity: Two 45-50 minute class periods.
- Stronger Hurricanes
- Kerry Emanuels Home page: Hurricanes
- Hurricane expert reconsiders global warmings impact
- Global Warming and Hurricanes
- Atlantic Hurricanes With Dr. Jeff Halverson Understanding the 21st Centurys New Threat
- Is Global Warming Making Hurricanes Worse
- Hurricanes, Climate, and Katrina: Research, Reviews, and Articles from Science Online
- Hurricanes and Global Warming FAQs
- Historical Hurricane Information
- Live Access Server (Advanced Edition)
There are four factors that contribute to the birth and growth of a hurricane. They are low pressure, warm temperatures, availability of a warm water source, and tropical wind patterns. Hurricanes have the ability to either grow stronger or weaker, depending on these four factors.
Hurricanes in the Northern Hemisphere usually begin by traveling from east to west. As the storms approach the coast of North America or Asia, however, they shift to a more northerly direction. All hurricanes eventually move toward higher latitudes where there is colder air, less moisture, and greater wind shears. These conditions cause the storm to weaken and die out. The end comes quickly if a hurricane moves over land, because it no longer receives heat energy and moisture from warm tropical water. Heavy rains may continue, however, even after the winds have diminished. It is also possible for a hurricane to stall and grow in size and intensity if the conditions are right. This was the case with hurricane Katrina that hit Louisiana in 2005.
- Go the the Live Access Server using the link in the Lesson Links section
- Click on Oceans
- Click on Weekly Sea Surface Temperature (NAVOCEANO).
- Enter the following coordinates below the map to the left, 60N through 30S of latitude and 120W through 0 degrees of longitude.
- Change the date to 13 September 1999.
- Click Update Plot at the top to make the changes to your plot.
- Be sure to to print or save the output image to look at when answering the questions.
Repeat these steps for the following hurricanes and their corresponding dates,
- Hurricane Iris, 09-October-2001
- Hurricane Isabel, 08-September-2003
- Hurricane Rita, 19-September-2005
- Hurricane Felix, 03-September-2007
- Hurricane Bill, 17-August-2009
To answer the questions you will have to use the 'Historical Hurricane Information' link along side the Live Access Server images. Once you arrive at the page, you will be at the 1999 hurricane season information page, all other years will become available at the top of the page without having to return to the main link on the lesson page. You will find a great deal of information about the individual hurricanes in the first few pages of the individual information sections.
- Are there any noticeable differences in the LAS images that you produced?
- Is there a relationship between sea surface temperature (LAS image) and hurricane intensity (found in the historical information link)?
- If there was a continual increase in temperature over time, how do you think this would affect hurricanes?
- If there was a continual decrease in temperature over time, how do you think this would affect hurricanes?
- From the information found in the 'Historical Hurricane Information' link, what can be said for hurricane frequency as time passes?
- Based on your research, what implications are there for those who live along a hurricane-affected coast line? Be sure to explain your answer based on the ideas of 'intensity' and 'frequency'.
Based on your research in answering the questions above, write 1-2 paragraphs summarizing what trends, if any, might be present in future hurricanes. Be sure to differentiate between the scientific meaning of hurricane 'intensity' and 'frequency'.
Lesson plan contributed by Zach Miller and ESSEA members