 |
|
Warmer seas linked to strengthening hurricanes: FSU study fuels global warming debate
September 04, 2008TALLAHASSEE, Fla. -- The theory that global warming may be contributing to stronger hurricanes in the Atlantic over the past 30 years is bolstered by a new study led by a Florida State University researcher. The study will be published in the Sept. 4 edition of the journal Nature.
Using global satellite data, FSU geography Professor James B. Elsner, University of Wisconsin-Madison Professor James P. Kossin and FSU postdoctoral researcher Thomas H. Jagger found that the strongest tropical cyclones are, in fact, getting stronger -- and that ocean temperatures play a role in driving this trend. This is consistent with the "heat-engine" theory of cyclone intensity.
"As seas warm, the ocean has more energy that can be converted to tropical cyclone wind," Elsner said. "Our results do not prove the heat-engine theory. We just show that the data are quite consistent with it."
Kerry Emanuel of the Massachusetts Institute of Technology first suggested the possible connection between global warming and increases in tropical cyclone intensity in a 2005 paper. He linked the increased intensity of storms to the heating of the oceans, which has been attributed to global warming.
Critics argued that the data were not reliable enough to make assertions about the relationship between climate change and hurricanes. Moreover, when scientists looked at the mean tropical cyclone statistics, they did not see an upward trend.
Elsner's team addressed both issues by using globally consistent, satellite-derived tropical cyclone wind speeds as opposed to the observational record and by focusing on the highest wind speeds of the strongest tropical cyclones each year.
Emanuel's theory is that the intake of warm air near the ocean surface and the exhaust of colder air above the cyclone is what drives a hurricane. Other factors being equal, the warmer the ocean, the warmer the intake of air. This heat-engine theory of how hurricanes increase their intensity is well accepted, but there are many environmental factors, such as wind shear, that might prevent a hurricane from strengthening, Elsner said.
To address that problem, Elsner's team looked at a subset of hurricanes that are closest to their maximum possible intensity (MPI). Under the heat-engine theory, every storm will lose some energy through inefficiency, and that loss will limit the storm's potential. The MPI represents the storm's maximum potential under ideal environmental conditions.
"We speculated that you might not see a trend in the intensity of typical hurricanes due to environmental factors, but if the heat-engine theory is correct, you should see a trend in the intensity of hurricanes at or near their MPI," Elsner said. "On average, the strongest storms are closest to their MPI."
The researchers created a data set from satellite observations of hurricane intensity of all tropical cyclones around the globe and looked at the maximum wind speeds for each one during a 25-year period. Tropical cyclones, which include hurricanes, typhoons and tropical storms, occur on average about 90 times per year worldwide.
The researchers found that the strongest tropical cyclones are getting stronger, particularly over the North Atlantic and Indian oceans. Wind speeds for the strongest tropical storms increased from an average of 140 mph in 1981 to 156 mph in 2006, while the ocean temperature, averaged globally over the all regions where tropical cyclones form, increased from 28.2 degrees Celsius to 28.5 degrees Celsius during this period.
"By creating a better, more consistent historical data set, we've been able to weed out quality issues that introduce a lot of uncertainty," Kossin said. "Then, by looking only at the strongest tropical cyclones, where the relationship between storms and climate is most pronounced, we are able to observe the increasing trends in storm intensity that both the theory and models say should be there."
While Elsner said the heat-engine theory might explain how tropical cyclones intensify given that everything else is the same, he noted, "We still do not have a complete understanding of why some cyclones intensify, sometimes quite rapidly, and others don't."
Florida State University
Kerry Emanuel of the Massachusetts Institute of Technology first suggested the possible connection between global warming and increases in tropical cyclone intensity in a 2005 paper. He linked the increased intensity of storms to the heating of the oceans, which has been attributed to global warming.
Critics argued that the data were not reliable enough to make assertions about the relationship between climate change and hurricanes. Moreover, when scientists looked at the mean tropical cyclone statistics, they did not see an upward trend.
Elsner's team addressed both issues by using globally consistent, satellite-derived tropical cyclone wind speeds as opposed to the observational record and by focusing on the highest wind speeds of the strongest tropical cyclones each year.
Emanuel's theory is that the intake of warm air near the ocean surface and the exhaust of colder air above the cyclone is what drives a hurricane. Other factors being equal, the warmer the ocean, the warmer the intake of air. This heat-engine theory of how hurricanes increase their intensity is well accepted, but there are many environmental factors, such as wind shear, that might prevent a hurricane from strengthening, Elsner said.
To address that problem, Elsner's team looked at a subset of hurricanes that are closest to their maximum possible intensity (MPI). Under the heat-engine theory, every storm will lose some energy through inefficiency, and that loss will limit the storm's potential. The MPI represents the storm's maximum potential under ideal environmental conditions.
"We speculated that you might not see a trend in the intensity of typical hurricanes due to environmental factors, but if the heat-engine theory is correct, you should see a trend in the intensity of hurricanes at or near their MPI," Elsner said. "On average, the strongest storms are closest to their MPI."
The researchers created a data set from satellite observations of hurricane intensity of all tropical cyclones around the globe and looked at the maximum wind speeds for each one during a 25-year period. Tropical cyclones, which include hurricanes, typhoons and tropical storms, occur on average about 90 times per year worldwide.
The researchers found that the strongest tropical cyclones are getting stronger, particularly over the North Atlantic and Indian oceans. Wind speeds for the strongest tropical storms increased from an average of 140 mph in 1981 to 156 mph in 2006, while the ocean temperature, averaged globally over the all regions where tropical cyclones form, increased from 28.2 degrees Celsius to 28.5 degrees Celsius during this period.
"By creating a better, more consistent historical data set, we've been able to weed out quality issues that introduce a lot of uncertainty," Kossin said. "Then, by looking only at the strongest tropical cyclones, where the relationship between storms and climate is most pronounced, we are able to observe the increasing trends in storm intensity that both the theory and models say should be there."
While Elsner said the heat-engine theory might explain how tropical cyclones intensify given that everything else is the same, he noted, "We still do not have a complete understanding of why some cyclones intensify, sometimes quite rapidly, and others don't."
Florida State University
Hurricanes Current Events and Hurricanes News RSSResearchers can predict hurricane-related power outages
Using data from Hurricane Katrina and four other destructive storms, researchers from Johns Hopkins and Texas A&M universities say they have found a way to accurately predict power outages in advance of a hurricane.
Seismic Noise Unearths Lost Hurricanes
Seismologists have found a new way to piece together the history of hurricanes in the North Atlantic - by looking back through records of the planet's seismic noise. It's an entirely new way to tap into the rich trove of seismic records, and the strategy might help establish a link between global warming and the frequency or intensity of hurricanes.
For safer emergencies, give your power generator some space
To subdue the steaming heat of hurricanes or to thaw out during a blizzard, gasoline-powered, portable generators are a lifeline during weather emergencies when homes are cut off without electricity.
Killer bees may increase food supplies for native bees
Aggressive African bees were accidentally released in Brazil in 1957. As "killer bees" spread northward, David Roubik, staff scientist at the Smithsonian Tropical Research Institute, began a 17-year study that revealed that Africanized bees caused less damage to native bees than changes in the weather and may have increased the availability of their food plants.
Storm Killers: LSU's Earth Scan Lab Tracks Cold Water Upwellings in Gulf
Complex interactions between the ocean and overlying atmosphere cause hurricanes to form, and also have a tremendous amount of influence on the path, intensity and duration of a hurricane or tropical weather event.
Hurricane frequency is up but not their strength, say Clemson researchers
In a new study, Clemson University researchers have concluded that the number of hurricanes and tropical storms in the Atlantic Basin is increasing, but there is no evidence that their individual strengths are any greater than storms of the past or that the chances of a U.S. strike are up.
Texas A&M researcher shows possible link between 1918 El Niño and flu pandemic
Research conducted at Texas A&M University casts doubts on the notion that El Niño has been getting stronger because of global warming and raises interesting questions about the relationship between El Niño and a severe flu pandemic 91 years ago.
Tornado threat increases as Gulf hurricanes get larger
Tornadoes that occur from hurricanes moving inland from the Gulf Coast are increasing in frequency, according to researchers at the Georgia Institute of Technology.
Rhododendron expansion may increase the chance of landslides on Southern Appalachian slopes
Research by U.S. Forest Service Southern Research Station (SRS) scientists and partners suggests that the expansion of rosebay rhododendron (Rhododendron maximum) in Southern Appalachian mountain hollows may increase the likelihood of landslides during and after intense rain events.
Tropical storms endure over wet land, fizzle over dry
If it has already rained, it's going to continue to pour, according to a Purdue University study of how ocean-origin storms behave when they come ashore.
More Hurricanes Current Events and Hurricanes News Articles
 |
The Wrath of God, Disasters in America - The Hurricanes: Deadly Wind, Deadly Rain (History Channel) Starring: Artist Not Provided They are storms that can reach 600 miles across dumping torrential rains and battering the landscape with winds that easily exceed 100 miles per hour. They can put islands underwater level cities and kill thousands of people.Only one or two hurricanes hit U.S. soil each year but when they do the repercussions are enormous. Widespread panic and staggering loss of life and property come with them often made worse when people foolishly think that the calm of the eye of the storm indicates that danger has passed. HURRICANES reveals how scientists have made great strides understanding and predicting these storms in the 20th century. But as the population in America's coastal areas increases their threat remains undiminished. By profiling three awesome storms the "big one" in Miami in 1926 the... |
 |
Miami Hurricanes NCAA Light Weight Fleece Blanket (031 Series) (50"x60") by Northwest This is the softest, brightest, and plushest printed blanket on the planet! This luxurious throw can be used at the game, on a picnic, in the bedroom, or cuddle under it in the den while watching the game. These blankets are extra warm and have superior durability. They are easy to care for, and are machine washable and dryable. The throw blanket is made of acrylic and polyester. |
 |
Hurricanes by Seymour Simon (Author) Hurricanes. Typhoons. Cyclones. No matter what you call them, these formidable, swirling storms are the most devastating events in nature. hurricanes takes young readers on an in-depth exploration of one of the most awe-inspiring phenomena on Earth! This dramatic account of hurricanes and the disasters they leave behind, including Andrew and Katrina, are intensified through arresting full-color photographs and satellite images. Award-winning science writer Seymour Simon has teamed up with the Smithsonian Institution to bring you a new, updated edition of his acclaimed look at this astonishing, and often terrifying, natural disaster. |
 |
National Geographic - Inside Hurricane Katrina Studio: Warner Home Video Release Date: 01/17/2006 Rating: Nr |
 |
The Very Best of Johnny & The Hurricanes by Johnny & The Hurricanes Johnny & The Hurricanes, The Very Best of Johnny & The Hurricanes |
 |
Butterflies and Hurricanes Muse (Primary Contributor) |
 |
Hurricane Force: Forecasting a Storm Science of Hurricanes will answer the most basic and profound questions about hurricanes. It will examine why they form, how they move, and what we know about the ingredients that create their destructive power. It will unravel the mystery behind hurricane predictions, the science and technology used to produce them, and show the devastation that drives forecasters to get people out of harms way. The program will also explore the latest theories about aspects of hurricanes that we do not fully understand, like rapid storm intensification, and the conditions that spawn more active and devastating hurricane seasons. These concepts will be presented through insightful narration and interviews with some of the world's leading hurricane experts, and illustrated with an exciting array of storm... |
 |
Divine Wind: The History and Science of Hurricanes by Kerry Emanuel (Author) Imagine standing at the center of a Roman coliseum that is 20 miles across, with walls that soar 10 miles into the sky, towering walls with cascades of ice crystals falling along its brilliantly white surface. That's what it's like to stand in the eye of a hurricane. In Divine Wind, Kerry Emanuel, one of the world's leading authorities on hurricanes, gives us an engaging account of these awe-inspiring meteorological events, revealing how hurricanes and typhoons have literally altered human history, thwarting military incursions and changing the course of explorations. Offering an account of the physics of the tropical atmosphere, the author explains how such benign climates give rise to the most powerful storms in the world and tells what modern science has learned about them. Interwoven... |
 |
Hello Hurricane by Switchfoot Switchfoot is an alternative rock band from San Diego, CA. They are known for their energetic live shows, the three guitarists in the line-up often operate simultaneously, building on the pop sensibilities of Foreman's songwriting, rounded out by Fontamillas's work on the synthesizer, bringing his industrial roots to the sound, the band works up 'the Switchfoot sound'- a melodic crunch of densely layered sound featuring some electronic experimentation, and often driven by hard-charging guitar riffs, while throwing in a few softer ballads as well. |
 |
Merona® Womens Cozy Furlined Cardigan - Hurricane Gray - XS by Merona |
| © 2009 BrightSurf.com |