|MadSci Network: Earth Sciences|
Hi Janaayman, Because hurricanes require warm water to maintain their strength, yes a large enough landmass will weaken a hurricane before entering the Gulf. So a landmass in the Florida Strait would affect hurricanes crossing it. Whether or not it would make any practical difference is a completely different matter. As shown by this graphic from the National Hurricane Center, Katrina came right across the Florida Peninsula, and reintensified to briefly be a Category Five storm on the Saffir-Simpson hurricane scale. Of course, there are also other pathways into the Gulf, as well as the Gulf's own indigenous storms. The reason filling the Florida Straits would not likely dampen hurricane frequency or intensity on the northern Gulf Coast is because hurricanes exist to correct an imbalance in the distribution of energy in the planetary climate system. Heat from the ocean is removed and redistributed to higher in the atmosphere, and as the the storm travels, to other latitudes or inland. As long as the Gulf is there, in the summer months there will be energy to dissipate. Another way in which this heat imbalance can be reduced is through ocean currents. One of these, the Florida Current, passes right through the Florida Straits between Florida and Cuba and later joins the Gulf Stream, a powerful current that runs up the Atlantic coast of the US and helps to contribute to a warmer climate as far away as Norway. The problem is that you dam up the path of the Florida Current, it is possible that you could increase the temperature of the Gulf, and therefore produce more intense hurricanes. A more rigorous estimation of that effect would probably require some pretty complex ocean-coupled climate models. The scale of such a project, and the enormous ecological ramifications in addition to potential for regional climate effects would preclude it from ever being considered, of course. Big storms have happened in the past, and they will continue to happen from time to time in the future. The most reasonable way to respond to this inevitability is through adequate building codes, intelligent planning of coastal communities, and moving out of the way when hurricanes approach. --Gene
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