About Jeff Masters
Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather
Intense New England Hurricanes Much More Numerous 340 to 1800 Years Ago
By: Jeff Masters , 6:43 PM GMT on February 17, 2015
Numerous Category 3 and 4 hurricanes frequently pounded New England during the first millennium, from the peak of the Roman Empire into the height of the Middle Ages, said a study accepted for publication this month in the open-access journal Earth’s Future, Climate Forcing of Unprecedented Intense-Hurricane Activity in the Last 2,000 Years. These prehistoric hurricanes were stronger than any hurricane documented to hit the region since the mid-1800s, and would be catastrophic if they hit the region today, according to Jeff Donnelly, a scientist at Woods Hole Oceanographic Institution (WHOI) in Massachusetts and lead author of the new paper. In a press release, Donnelly said, “We hope this study broadens our sense of what is possible and what we should expect in a warmer climate. We may need to begin planning for a category 3 hurricane landfall every decade or so rather than every 100 or 200 years.”
Figure 1. The storm surge from Category 2 Hurricane Carol in 1954 batters New England's Edgewood Yacht Club near Providence, Rhode Island. Image credit: NOAA Photo Library.
The paper is the latest contribution to the field of paleotempestology--the study of past tropical cyclone activity by means sediment deposits, cave speleothems, tree rings, coral deposits, as well as historical documentary records. In this case, the researchers took sediment cores from Salt Pond near Falmouth on Cape Cod, Massachusetts. 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, storm surges from Category 2 and stronger hurricanes have deposited sediment over the barrier and into the pond. The scientists were able to calibrate the timing of the intense hurricane strikes by dating the layers from Category 2 Hurricane Bob of 1991, the 1675 (September 7) New England hurricane, and the Great Colonial Hurricane of 1635, which passed across southeastern New England and caused widespread damage consistent with a category 3 hurricane.
Figure 2. Scientists collect a sediment core from Salt Pond in Falmouth, Massachusetts, to study hurricane overwash deposits placed there by storm surges from intense hurricanes. The aluminum tube was vibrated into the muddy sediment at the bottom of the pond and then extracted with a hoist. Image Credit: WHOI
The prehistoric sediments showed that there were two periods of elevated intense hurricane activity on Cape Cod--from 150 to 1150, and from 1400 to 1675. Previous paleotempestology studies also found evidence of high hurricane activity during 150 - 1150 A.D. from the Caribbean to the Gulf Coast. Both time periods had unusually warm sea surface temperatures (SSTs) in the Main Development Region for hurricanes, from the Caribbean to the coast of Africa. Warm ocean temperatures in this region have been linked to increased intense hurricane activity by a number of recent research papers. In recent decades, ocean temperatures in the Main Development Region have surpassed the warmth of prehistoric levels, and these waters are expected to warm further over the next century as the climate heats up, suggesting that intense hurricane activity in New England may return to the levels of 340 to 1800 years ago. However, other factors besides warming SSTs will also shape what happens in the North Atlantic. For example, the pattern of ocean warming could bring more El Niño-style wind shear to the Atlantic, reducing hurricane activity. Still, New England would be wise to take heed of Donnelly's advice that we may need to begin planning for a category 3 hurricane landfall every decade or so rather than every 100 or 200 years.
Jeff Masters
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.
Reader Comments
Category 6™
236. KEEPEROFTHEGATE (Mod)
it is happening
its cold air displacement from abnormal jet patterns
and warm areas over the high north warmer waters under the ice
causing air too find new colder areas to settle into
trying to establish new cold core regions
maybe just a guess
its climate change and every region on the globe
is experiencing changes to there patterns
235. Pallis1
234. TimTheWxMan
With a highly amplified jet stream due to a blocking high over Cali, it's unusually warm (and dry) out west and pretty cold in the eastern half of the country.
233. beell
Sorry,Ped. It don't count. You're left coast.
:)
232. Methurricanes
calling me ignorant based off your gross misrepresentation of history is utterly insane.
Just incase if there was any question of what "Rights" the south was "protecting"
from the SC Declaration of Secession
"Those States have assumed the right of deciding upon the propriety of our domestic institutions; and have denied the rights of property established in fifteen of the States and recognized by the Constitution; they have denounced as sinful the institution of Slavery"
231. Naga5000
Why shouldn't it be possible? Cold air is still cold, this is a displacement of cold air spilling into areas it normally isn't.
230. Pallis1
229. ClimateChange
I don't know. It seemed like in past blocking episodes it didn't get all that cold. Was mostly hype. But something changed last winter and this winter. We're seeing record cold. That shouldn't be possible with today's globally warmed atmosphere.
228. Naga5000
I would "blame" it on the temperature of the air, after all Anchorage is warming at the rate of about 1.18 C per century, but then again I'm not into perpetuating conspiracy theories about faulty equipment and UHI since those things are checked and adjusted for.
227. TimTheWxMan
226. LAbonbon
Night, all.
225. Pallis1
224. Chucktown
Per NWS Anchorage twitter today:
@NWSAnchorage: Missed it by that much. Today's high in #Anchorage reached 44º... 45º was the record set in 1920. #AKwx #Alaska
223. KEEPEROFTHEGATE (Mod)
222. BaltimoreBrian
221. PedleyCA
So, that makes me Southern and those in Canoga Park are Northern, too funny...
220. WaterWitch11
are you sure florida counts??? i know its swamp land but i am not so sure :)
219. Naga5000
Ok, last statement about Bob...Bob is great because they can only look for Bob's in this location using this method. They aren't looking for all systems, or even some systems, they are looking for guys who look like Bob because it's the only thing they can look for with any accuracy using this specific method at this specific location, they weren't trying to generalize and state as much.
Now on to the meat...I reject the soft versus hard science thing. That's something people like to say to separate themselves from guys like me when we start talking about institutions, structures, power, etc., I like to remind them our methods are based in the same conceptual framework only what we study is different. I think the soft / hard science thing died out awhile ago anyways, I don't hear it much anymore. Besides, my checks and my diplomas say College of Sciences on them same as the "hard" science guys.
You aren't going to like my response about rewriting that paragraph, yes I could rewrite it to make it more readable and understandable to the average person, but I don't think it's the publication itself's job to do it. Journal articles are written in a specific way, it's a discourse between scientists not a communication to the masses. Don't get me wrong, I think there needs to be better communication of studies, but I don't think that comes from changing the wording and stylistic flair within academic writing. I think that comes from removing the sensationalism that comes with reporting on science. I think scientists should stop making hyperreal comments designed to be attention grabbers and not literally correct. I think it would be good if there were scientists/journalists who were trustworthy interpreters to the general public and that scientific research still was regarded as holding privilege in informational creation. Heck, I might even go as far as to argue that a second copy written in more clear language should be made for communicative purposes, but for lack of a better term "dumbing down" academic writing is not the way to go.
Reforming the system would break the system. We are taught to write in certain ways because we are judged in peer review by others who have been taught to write that way and worse, we teach new people to write that way because if they don't the old guard won't publish them. It's completely tautological nonsense, but it's the way it works, and changing it would mean a complete reworking of the system and these ivory towers aren't coming down anytime soon.
Besides my two skills in life are sociology and being able to read journal level articles...what would I do if you took away one of my niches? :)
218. KEEPEROFTHEGATE (Mod)
217. LAbonbon
Not sure I should ask, Pallis, but what's the ESA Swarm mission?
216. LAbonbon
If you ran a pool I think I could clean up
215. KEEPEROFTHEGATE (Mod)
214. LAbonbon
213. hurricanes2018
212. sar2401
But I can't, darn it. :-)
211. Pallis1
210. washingtonian115
209. LAbonbon
Actually, Scott - I'm aware of these points. I appreciate you taking the time and posting them, and for sharing your paper :P
The discussion in the paper is not nearly so straightforward as your summary just was. They discuss it in sections 2.6 (Methods) and 3.1.3 (Results). Here is 3.1.3:
"3.1.3 Changes in event frequency
The Salt Pond record indicates considerable changes in the frequency of event beds over the
last 2000 years, with historically unprecedented intervals of event-bed deposition. A total of
thirty-five event layers were deposited over the last 2000 years (Figs. 2a and 3a); the highest
frequencies were reached at 1420-1675 CE (10 event beds, #2-11) and 150-1150 CE (23
event beds, #13-35). Assuming hurricane landfall occurrence follows a Poisson process we
can estimate the probability of exceeding the number of events expected by random chance
alone. For example, using 0.9 events per century as the expected rate (λ) (derived from the
162-year NOAA Best Track Dataset, Supplementary Fig. 4), the probability of experiencing three or more events in any one century is 0.06 (6%). Several intervals in the 4th to 7th centuries, 11th century, and 15th to early 17th centuries exceed this frequency (Fig. 3a). The
probability of experiencing one or more events in any one century is 0.6 (60%). However, the
probability of experiencing ten consecutive centuries with one or more events per century, as
recorded at Salt Pond between ca. 150 and 1150 CE, is quite low at 0.006 (0.6%). Similarly,
the probability of experiencing two or more events in two consecutive centuries, as
reconstructed in Salt Pond between ca. 1440 and 1640 CE (Fig. 3a), is only 0.04 (4%), and in
fact event bed frequency exceeds three events per century through most of this interval.
Hence, compared to modern event frequencies in the region, significant portions of the 2,000
year Salt Pond record exceed what would be expected based on random event occurrence
alone."
The original question was, where did the 'decade' comment come from? I made a stab/guess at it in an earlier post, but would love to hear your thoughts, if you have time to read the study. If not, no worries :)
208. sar2401
207. hurricanes2018
205. sar2401
South Carolina
Mississippi
Florida
Alabama
Georgia
Louisiana
Texas
Virginia
Arkansas
North Carolina
Tennessee
These are the states of the Confederacy. There no other Southern states. There are other states in the south, but it's not the same.
204. TimTheWxMan
The civil war battles are named differently too. For example, southerners call the Battle of Bull Run the Battle of Manassas.
203. sar2401
202. TimTheWxMan
The South could also be defined based on their political leanings too. They're also heavily religious.
201. sar2401
200. JohnLonergan
199. TimTheWxMan
Uhhh.... what?
198. nymore
197. TimTheWxMan
One of my geography books puts St. Louis and Pittsburgh as part of the "inland south". Ah shure don't sound lak a sutherner... y'all.
196. ColoradoBob1
195. TimTheWxMan
The Taino one's better.
194. BaltimoreBrian
193. TimTheWxMan
Well, he is from Colorado so yeah.
192. Pallis1
191. TimTheWxMan
There's more than one way to define the South. One is their ability (or lack thereof) to handle winter weather and treating one inch of snow like the apocalypse (Atlanta looking like a scene out of the walking dead last year). :O)
190. washingtonian115
189. Pallis1
188. sar2401
187. sar2401
186. ScottLincoln
I have not read much about the paper in question but have seen some of the discussion on it.
With regards to average recurrence interval (ARI), a relatively modern term I prefer over the similar terms "return period" or "return interval", there are a few things that people frequently misunderstand.
1) The value corresponds to a long term average, and should not be used as some sort of expectation of when an event will occur. Comments like "we are overdue" are not warranted when discussing an ARI; one needs to look at the underlying physical mechanisms which will provide better information to use in forecasting events.
2) The majority of the time something is assigned a "return period" or ARI, the chance of occurance is independent, or near independent, from surrounding years. So just because you had a "100 year" (1% chance) flood last year doesn't mean that you chance is reduced this year.
3) The most extreme (most rare) part of an event is often very isolated and not experienced by the vast majority of persons who think that they experienced it. Here's an example to illustrate. Summer, 1993, in the midwest. Most of the state of Iowa experienced heavy rainfall and most rivers experienced decent river rises. A few locations, on a few rivers, had conditions that were classified as "100-year" or greater events. Probably 10% or fewer people actually experienced flooding of that magnitude (the 100 year or 500 year in the hardest hit areas) but many will calibrate to the event as if they had experienced such an event. Not to say that they didn't experience flooding, but they didn't experience the 100 year or greater. Another example: see Fig 10 in this paper. That event was a particularly significant event for the southeast Louisiana and southern Mississippi area and almost everyone in the area recalls it and discusses how bad it was. Yet if you look at the rainfall ARI analysis, only small portions of 3 counties experienced 1000-year (0.1% chance) event and most events I've studied have a much smaller spatial coverage of the maximum.
Does any of that help?