Monday, May 21, 2007

Global climate change and hurricanes

Climate Feedback: The 2007 hurricane season is about to get officially underway. Never mind that nature has already provided the first named storm in the North Atlantic: Andrea. Several forecasts suggest that the 2007 season in the North Atlantic will be well above average. Sea surface temperatures (SSTs) are above normal and atmospheric conditions look likely to be favorable for tropical storm activity….

What we expect from the dynamics is that the storms will experience increased intensity because there is more fuel for the storms (higher SSTs and more water vapor) but stronger storms take more energy out of the ocean and leave behind a colder wake, and so the expectation is that numbers could actually decrease. There is some evidence to suggest that size, and thus damage, may increase, but there are no statistics on size at all. A key issue for the Landsea paper is what about duration? As long as the storms keep moving to a new piece of ocean they do not get affected by the cold wake, and so in recent times the storms may be developing farther to the east and this may mean there are fewer storms missed than Landsea claims. Moreover, storms that were east of 55 degrees W that might not have been subject to aircraft surveillance tend to move west into the area where they are tracked, and so all that may be missing is a bit at the start of the storm?

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