Waves Along Florida East Coast Becoming More Volatile
FORT MYERS - Wave activity in the Atlantic Ocean has become more volatile in the past 10 years, according to researchers and scientists in Florida. Nearshore waves on Florida's east coast that once held steady at an annually-based average of 2.8 feet now fluctuate between 2.3 feet and 3 feet.
The variations may seem small, but they are significant, according to William Dally, Ph.D., P.E., principal of Surfbreak Engineering Sciences, Inc., based in Winter Park, Fla.
Scientists classify nearshore waves as those that occur within a few thousand feet of the coast. Because the record from ocean buoys is relatively short, they have been developing the data by transforming long-term 'hindcasted' offshore water wave information to shallow water using computer models. ? ?"We have been developing computer-generated nearshore wave information in the Atlantic Ocean that covers the last 50 years," Dally said. "We found the nearshore wave activity from was stable between 1975 and 1996 but, since 1996, there has been a lot of volatility."
Scientist use a 365-day-long running average of wave heights to examine the 50-year wave record for patterns and trends. From 1975 to 1996, the average wave height held steady at approximately 2.8 feet. In 1997, it dropped to its lowest level of 2.3 feet. The number rose again around 2002, before dropping down again in 2003.
In 2004, average wave heights began to rise again, and in 2005, reached a level of 3 feet - equal to the all-time high on record, which occurred in 1969.
In years with few or no major nor'easters, researchers say average wave heights decrease and waves approaching from the south dominate. In years when the nor'easters return, the average wave height increases and waves from the north dominate.
"The increase in variability of the occurrence of nor'easters that began in 1996 is particularly intriguing," Dally said. "The results we have currently run to the end of 2005. It will be interesting to see what the 2006-2008 information shows when it becomes available later this year."
(This information is provided by the American Shore & Beach Preservation Association.)
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