James Elsner and Thomas Jagger of Florida State University in Tallahassee after examining the past 100 year hurricane records of the United States and Caribbean conclude that their intensity may be linked to 10 to 12 year solar magnetic activity cycles. Data from the National Hurricane Center, Miami, Florida was used in the study.
Sunspots are areas in sun with increased magnetic activity. The number of sunspots vary during the solar cycles. The number of sunspots is predicted by NOAA to be the lowest in 2008 in a 11 year cycle. This decrease in the number of sunspots may related to increased hurricane intensity on earth.
Increased solar activity will allow more ultraviolet rays to reach earth, that can warm the relatively colder upper atmosphere. This decreases the temperature difference between the upper and lower regions of the atmosphere. Decreased solar activity reverses this phenomenon. The more the temperature difference between upper and lower atmospheric regions, the higher will be the hurricane intensity.
Establishing a link between sunspots and hurricane intensity can provide a valuable tool for predicting storms. Other scientists however question the statistical basis of the study and the physical processes attributed to changes in hurricane activity.
"This is something worth investigating, but they made too many assumptions for me to just accept their conclusion at this point," says Judy Curry of Georgia Institute of Technology, Atlanta.
Reported by Wikinews
Elsner, J. B. & Jagger, T. J. "United States and Caribbean tropical cyclone activity related to the solar cycle". Geophysical Research Letters, September 19, 2008
"Sunspot-hurricane link proposed". Free Republic, September 28, 2008
"Increased solar activity results in decrease in hurricane intensity". Yahoo! News, September 29, 2008