Are Storms getting Stronger?
Research has mostly been focused on short-term forecasting when it comes to hurricanes, winter storms, thunderstorms and tornadoes with much less focus on how storms are changing over long periods of time due to a lack of reliable, long-term records.
However, there are new efforts directed on the study of how the changing climate is impacting storms and so far there is a growing consensus that global warming may be producing stronger, but fewer storms, according to a new report from NASA's Earth Observatory.
After Sandy devastated parts of the Northeast coast last year there were many questions about whether or not climate change had caused Sandy to be such an extreme event.
Key excerpts from the NASA article.........
Rising sea levels exacerbated Sandy’s storm surge, for example, a direct link between global warming and storm damage. And abnormally high sea surface temperatures in the Atlantic probably intensified the storm. But pinning all of Sandy’s fury—its hybrid nature, the scale of its winds, its unusual track—on global warming is premature, says Shepherd, the current president of the American Meteorological Society.
Storms feed off of latent heat, which is why scientists think global warming is strengthening storms. Extra heat in the atmosphere or ocean nourishes storms; the more heat energy that goes in, the more vigorously a weather system can churn.
A study based on over 20 years of satellite altimeter data showed that hurricanes intensify faster now than what they did 25 years ago, according to the report.
Extra water vapor in the atmosphere is also making storms wetter. Over the past 25 years, satellites have detected a 4 percent rise in water vapor in the air column.
Climatologists think the differing rates of warming from the equator to the poles could have a significant impact on some types of storms. Extra-tropical cyclones, for example, harvest energy from the atmosphere when masses of warm and cold air interact along the polar front—the boundary between cooler polar air and warmer subtropical air. As the difference between the temperature at the poles and the tropics decreases, there could be less energy for these storms to absorb, a change that could weaken them or make them less frequent. (via NASA)
Latest research also suggests that Atlantic wind shear could increase by 1 to 2 mph for each degree that global temperatures increase, which is why many climate simulations project that the number of tropical cyclones will stay the same or decrease while the strongest storms get stronger.
There has also been new research showing a possible link between Arctic sea ice extent and a slowing of the jet stream winds across the far north, which would lead to more high latitude blocking and the potential for colder, stormier weather farther to the south.
Climate change should, theoretically, increase potential storm energy by warming the surface and putting more moisture in the air through evaporation, says Harold Brooks, a meteorologist at NOAA’s National Severe Storms Laboratory. But on the other hand, disproportionate warming in the Arctic should lead to less wind shear in the mid-latitude areas prone to severe thunderstorms, making the storms less likely.
However, Another study, led by Robert Trapp of Purdue University, found that a doubling of greenhouse gases in the atmosphere would significantly increase the number of days that severe thunderstorms could occur in the southern and eastern United States. Cities such as Atlanta and New York could see a doubling of the number of days that severe thunderstorms could occur, the models suggested. “The increase in CAPE more than compensated for the decrease in wind shear,” Trapp says.
When it comes to the strength and number of tornadoes, there is just too much uncertainty at this point on whether or not climate change will have a significant impact.Report a Typo