Hurricane

In 2010, there were 14 named storms, of which 7 were hurricanes and 5 were major hurricanes (that is, category-3, 4 and 5 ones). Hurricane activity this year was about 1.5 times the median hurricane activity level.A hurricane is an intense tropical storm. Tropical storms form over warm tropical oceans when local sea surface temperatures are above 26.5°C (80°F) through a depth of at least 50 meters (160 ft). Under these conditions, evaporation from the ocean surface creates very high humidity in the atmosphere, which in turn generates thunderstorms.

A surefire way to kill a hurricane? Add something called “vertical wind shear” — essentially a change in wind speed and direction with height. It stops the storm from forming in its tracks by ripping it apart.  Another way to kill a hurricane? Whip up a wind across the deserts of northern Africa. Dust gets swept up into the air and helps damp down developing storms. (In fact, it’s the effect of the dust combined with vertical wind shear and super-dry air that’s the killer.)

There’s a school of thought that says that climate change should fuel more hurricanes and more intense ones, because as the planet warms, ocean waters warm and sea surface temperature rises.

In a paper published earlier this year in Science, Thomas R. Knutson, of the Geophysical Fluid Dynamics Laboratory at the National Oceanic and Atmospheric Administration (NOAA) and co-authors suggest that we should expect an increase in the frequency of the strongest hurricanes in the Atlantic, roughly by a factor of two by the end of the century, despite a decrease in the overall number of hurricanes. “But we should not expect this trend to be clearly detectable until we near the end of the century, given a scenario in which CO2 [carbon dioxide] doubles by 2100.” The relationship will become more apparent as we improve our understanding and data and as the climate continues to warm.