A new press release from AGU, suggests past data shows this to be true, but Dr. Philip Klotzbach suggests this graph of current data and notes:
“Florida Peninsula and East Coast has seen a downturn in major hurricanes. Only 40% as many impacts the past 50 yrs.”
Monster hurricanes reached US Northeast during prehistoric periods of ocean warming
Joint release: AGU, WHOI, NSF
WASHINGTON, D.C. – Intense hurricanes possibly more powerful than any storms New England has experienced in recorded history frequently pounded the region during the first millennium, from the peak of the Roman Empire into the height of the Middle Ages, according to a new study. The findings could have implications for the intensity and frequency of hurricanes that the U.S. East and Gulf coasts could experience as ocean temperatures increase as a result of climate change, according to the study’s authors.
A new record of sediment deposits from Cape Cod, Mass., show evidence that 23 severe hurricanes hit New England between the years 250 and 1150, the equivalent of a severe storm about once every 40 years on average. Many of these hurricanes were likely more intense than any that have hit the area in recorded history, according to the study. The prehistoric hurricanes were likely category 3 storms – like Hurricane Katrina — or category 4 storms – like Hurricane Hugo — that would be catastrophic if they hit the region today, according to Jeff Donnelly, a scientist at Woods Hole Oceanographic Institution in Massachusetts and lead author of the new paper accepted for publication in Earth’s Future, a journal of the American Geophysical Union.
The study is the first to find evidence of historically unprecedented hurricane activity along the northern East Coast of the United States, Donnelly said. It also extends the hurricane record for the region by hundreds of years, back to the first century, he said.
“These records suggest that the pre-historical interval was unlike what we’ve seen in the last few hundred years,” said Donnelly.
The most powerful storm to ever hit Cape Cod in recent history was Hurricane Bob in 1991, a category 2 storm that was one of the costliest in New England history. Storms of that intensity have only reached the region three times since the 1600s, according to Donnelly.
The intense prehistoric hurricanes were fueled in part by warmer sea surface temperatures in the Atlantic Ocean during the ancient period investigated than have been the norm off the U.S. East Coast over the last few hundred years, according to the study. However, as oceans temperatures have slowly inched upward in recent decades, the tropical North Atlantic sea surface has surpassed the warmth of prehistoric levels and is expected to warm further over the next century as the climate heats up, Donnelly said.
He said the new study could help scientists better predict the frequency and intensity of hurricanes that could hit the U.S. East and Gulf coasts in the future.
“We hope this study broadens our sense of what is possible and what we should expect in a warmer climate,” Donnelly said. “We may need to begin planning for a category 3 hurricane landfall every decade or so rather than every 100 or 200 years.”
“The risk may be much greater than we anticipated,” he added.
Donnelly and his colleagues examined sediment deposits from Salt Pond near Falmouth on Cape Cod. The pond is separated from the ocean by a 1.3- to 1.8-meter (4.3- to 5.9-foot) high sand barrier. Over hundreds of years, strong hurricanes have deposited sediment over the barrier and into the pond where it has remained undisturbed.
The researchers extracted nine-meter (30-foot) deep sediment cores that they then analyzed in a laboratory. Similar to reading a tree ring to tell the age of a tree and the climate conditions that existed in a given year, scientists can read the sediment cores to tell when intense hurricanes occurred.
The study’s authors found evidence of 32 prehistoric hurricanes, along with the remains of three documented storms that occurred in 1991, 1675 and 1635.
The prehistoric sediments showed that there were two periods of elevated intense hurricane activity on Cape Cod – from 150 to 1150 and 1400 to 1675. The earlier period of powerful hurricane activity matched previous studies that found evidence of high hurricane activity during the same period in more southerly areas of the western North Atlantic Ocean basin – from the Caribbean to the Gulf Coast. The new study suggests that many powerful storms spawned in the tropical Atlantic Ocean between 250 and 1150 also battered the U.S. East Coast.
The deposits revealed that these early storms were more frequent, and in some cases were likely more intense, than the most severe hurricanes Cape Cod has seen in historical times, including Hurricane Bob in 1991 and a 1635 hurricane that generated a 20-foot storm surge, according to Donnelly.
High hurricane activity continued in the Caribbean and Gulf of Mexico until 1400, although there was a lull in hurricane activity during this time in New England, according to the new study. A shift in hurricane activity in the North Atlantic occurred around 1400 when activity picked up from the Bahamas to New England until about 1675.
The periods of intense hurricanes uncovered by the new research were driven in part by intervals of warm sea surface temperatures that previous research has shown occurred during these time periods, according to the new study. Previous research has also shown that warmer ocean surface temperatures fuel more powerful storms.
The sediment coring and analysis by Donnelly and his colleagues “is really nice work because it gives us a much longer period perspective on hurricanes,” said Kerry Emanuel, a professor of atmospheric science at the Massachusetts Institute of Technology in Cambridge. “It gives you something that you otherwise wouldn’t have any knowledge of.”
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The new research was funded in part by the National Science Foundation’s Division of Ocean Sciences.
The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation on Facebook, Twitter, YouTube, and our other social media channels.
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Southeastern Virginia had our only historical major hurricanes during the LIA~!
How much does the quality of the fuel impact the top speed of your automobile? It is a very small percentage of the total speed. A Viper will go many times faster than a go-kart using the exact same fuel. In other words, the quality of the fuel is just not that important, when compared to all the other factors.
Sea level water temperatures of about 80 degrees F qualify as fuel for tropical cyclones. Increasing the temperature of the water just doesn’t make a huge difference in the strength of the storm. Other factors, especially atmospheric conditions and tendencies, are vastly more important than water temperature, once the minimum threshold had been crossed.
The phrase, “…all else being equal…” is only relevant if there was any chance that all else could be equal. It is just not reasonable to draw any conclusions about hurricanes and water temperatures from the historical record, since the atmosphere has always been in flux, and that flux is orders of magnitude more important than a degree or two of water temperature.
The big thing here is that the AGU report states that the older period was considerably warmer than the current one. That is at odds with Michael Mann’s position and the eco-green who say today is “unprecedented”.
This makes good sense because during periods in which zonal flow predominates, as from 1965 to the present, high amplitude Rossby waves in the polar jet stream would tend to redistribute tropical heat poleward more efficiently than in periods in which zonal flow predominates, with lower amplitude waves, as from 1909 to 1965. Under zonal conditions, the lack of high amplitude Rossby waves to transfer tropical heat toward the poles would be compensated for by hurricanes performing that function.
I’d propose a new drinking game involving the phrase “much greater/worse than we anticipated/predicted,” but I fear we may all die of alcohol poisoning.
Now at a record stretch of years without ANY major hurricanes!
From the article;
A new record of sediment deposits from Cape Cod, Mass., show evidence that 23 severe hurricanes hit New England between the years 250 and 1150, the equivalent of a severe storm about once every 40 years on average. Many of these hurricanes were likely more intense than any that have hit the area in recorded history, according to the study.
The operative word in that paragraph is “likely”. Are there any records of permanent settlements along the East coast that long ago, can someone point me that direction? Because as I remember my history, some of the early settler’s descriptions and records are that they found little evidence of that until they travelled further inland.
Some folks predict and some folks plan. In the case of the already developed US east coast, none of this will matter. When the next “unprecedented hurricane takes a big chunk out of that development the response will be to rebuild it – with other people’s money.
Improvements are possible. After Hurricane Andrew (1992):
http://www.miamisci.org/hurricane/andrew.html
I have never understood why they allowed building on the ocean side of Rt. 9 (also the GS Parkway) in NJ. Seriously go look. The ocean is literally right there and you are maybe one or two feet above it. To make it worse, the are back bays on many communities that dot the Jersey coast.
I would ask a hurricane expert what increase in power could be expected by an x increase in ocean temps.
The last response I heard was that if ocean temps rose to the extent they were expecting back at the time of Katrina (a lot), the max wind speed would hardly have been affected – perhaps 5 mph faster. Hurricane experts provide the best evidence.
It occurs to me that those who believe global warming causes more (or more powerful) hurricanes simply don’t understand hurricanes. Warm oceans, in and of themselves, do not cause hurricanes. It is the temperature difference between the ocean surface and the upper troposphere. Yes, hurricanes tend to occur in the summer, when the oceans are at their warmest. But that is because seasonal warming is caused by more direct sunlight and less atmosphere to penetrate, and thus acts more directly on the surface, with a smaller effect on the upper atmosphere. The upper atmosphere is always cooler than the surface, so if the surface warms more than the upper atmosphere, the temperature difference INCREASES, resulting in a higher probability of hurricane formation.
Greenhouse warming, on the other hand, has its most direct effect on the upper atmosphere (that’s where the greenhouse gasses are after all). Only a fraction of the additional heat in the atmosphere finds its way back to the surface, so the upper atmosphere warms more than the surface. Again, the upper atmosphere is always cooler than the surface, so warming the upper atmosphere more than the surface necessarily REDUCES the temperature difference, thus decreasing the chance of hurricanes.
Of course, we are always going to have hurricanes in the summer, whether global warming continues (resumes?) or not, because, seasonal warming is much more powerful than the man-made portion of greenhouse warming. But it is obvious that greenhouse warming, if anything, will LESSEN the probability of hurricane formation, and those that do form will tend to be less powerful.
This is all Meteorology 101. Why should we believe the rantings of global warming alarmists when they are so BADLY mistaken on the basics of weather?
So how is it that WeatherAction UK can predict these extreme events many months in advance without using Global Warming theories? Just a laptop, not 93 Million pounds worth of super computer like the UK Met office?
It appears that only the abstract is released, along with Supporting Information. That seems about par for the “proof by press release” course.
Their Figure S4 (on page 9 of 15 (SI)) shows tracks for Cat 2 or above storms making landfall in New England over the past 162 years. Hurricane groupies know that the northeast quandrant of storms packs the biggest punch. Only one of the seven storm tracks shown on Fig S4 placed the subject Salt Pond in that quandrant. “Close enough” counts in horseshoes and hand grenades, but not hurricanes. It is extremely difficult to project even regional frequency from a single pond. It’s like looking for your lost car keys only under the street lights…
The 1915-1964 total of major hurricanes striking USA’s Florida peninsula or East Coast from 1915 to 1964 should be 22, not 23. The pair of maps have both of them showing the same 1965 hurricane.