Study: fewer Caribbean hurricanes during Maunder Minimum of solar activity

“We didn’t go looking for the Maunder Minimum, it just popped out of the data.”

Hurricane Katrina, Aug 28, 2005

Hurricane Katrina, Aug 28, 2005

From the UNIVERSITY OF ARIZONA

Shipwrecks, tree rings reveal Caribbean hurricanes in buccaneer era

Records of Spanish shipwrecks combined with tree-ring records show the period 1645 to 1715 had the fewest Caribbean hurricanes since 1500, according to new University of Arizona-led research. The study is the first to use shipwrecks as a proxy for hurricane activity.

The researchers found a 75 percent reduction in the number of Caribbean hurricanes from 1645-1715, a time with little sunspot activity and cool temperatures in the Northern Hemisphere.

“We’re the first to use shipwrecks to study hurricanes in the past,” said lead author Valerie Trouet, an associate professor in the UA Laboratory of Tree-Ring Research. “By combining shipwreck data and tree-ring data, we are extending the Caribbean hurricane record back in time and that improves our understanding of hurricane variability.”

Although global climate models indicate hurricanes will be more intense as the climate warms, those models are not yet good at making regional predictions, Trouet said. Learning more about how hurricanes correlated with climate for the past 500 years may lead to better regional predictions of hurricanes.

“We’re providing information that can help those models become more precise,” she said.

What is now the U.S. National Hurricane Center did not begin keeping records of Caribbean hurricanes until 1850, she said. Researchers have used lake sediments to develop a record of hurricanes over the past centuries, but these data provide only century-level resolution.

The new research provides an annual record of Caribbean hurricanes going back to the year 1500 – shortly after Christopher Columbus first reached the Caribbean.

Ship traffic between Spain and the Caribbean became commonplace. Spain kept detailed records of the comings and goings of ships–at the time, ships returning with gold and other goods provided the income for the Spanish kingdom. Storms were the major reason that ships wrecked in the Caribbean.

Figuring out how climate change affects hurricane activity is important for emergency management planning. For U.S. hurricanes from 1970 to 2002, other investigators estimated the damages cost $57 billion in 2015 dollars.

The team’s paper, “Shipwreck Rates Reveal Caribbean Tropical Cyclone Response to Past Radiative Forcing,” is scheduled to be published online by the Proceedings of the National Academy of Sciences the week of March 7.

Trouet’s co-authors are Grant Harley of the University of Southern Mississippi in Hattiesburg and Marta Domínguez-Delmás of the University of Santiago de Compostela in Lugo, Spain.

The University of Southern Mississippi, the National Science Foundation, the U.S. Fish and Wildlife Service and an Agnese N. Haury Visiting Scholar Fellowship supported the research.

Trouet and her coauthors hatched the idea for the study while sitting on the patio of Tucson’s Hotel Congress. The three scientists were attending the Second American Dendrochronology Conference, which was held in Tucson in 2013.

Harley mentioned he had tree-ring records from the Florida Keys that went back to 1707 – and that the tree rings revealed when hurricanes had occurred. The growth of trees is retarded in years with hurricanes. That reduction in growth is reflected in the tree’s annual rings.

Domínguez-Delmás, a dendroarchaelogist, figures out when Spanish ships were built by retrieving wood from shipwrecks and dating the wood. Trouet wondered whether the tree-ring record of Florida hurricanes could be combined with shipwreck data to create a long-term history of Caribbean hurricanes.

The team discovered that a book used by treasure hunters, Robert F. Marx’s book “Shipwrecks in the Americas: a complete guide to every major shipwreck in the Western Hemisphere,” had a detailed record of Caribbean shipwrecks. The team also used “Shipwrecks of Florida: A comprehensive listing,” by Steven D. Singer.

The books, combined with ship logs, allowed the researchers to compile a list of Spanish ships known to have been wrecked by storms during the hurricane seasons of 1495-1825. The team found that the hurricane patterns from the shipwreck database closely matched Florida Keys tree-ring chronology of hurricanes from 1707-1825.

In addition, the team compared the Florida Keys tree-ring records to the systematic recordings of hurricanes from 1850-2009. Again, the patterns matched.

When they overlapped the shipwreck data with the tree-ring data, the researchers discovered a 75 percent reduction in hurricane activity from 1645-1715, a time period known as the Maunder Minimum.

“We didn’t go looking for the Maunder Minimum,” Trouet said. “It just popped out of the data.”

The Maunder Minimum is so named because there was a low in sunspot activity during that time. Because Earth receives less solar radiation during lulls in sunspot activity, the Northern Hemisphere was cooler during the Maunder Minimum than in the time periods before or after.

Learning that a lull in Caribbean hurricanes corresponded to a time when Earth received less solar energy will help researchers better understand the influence of large changes in radiation, including that from greenhouse gas emissions, on hurricane activity.

Having better predictions about how anthropogenic climate change affects hurricane activity is important because hurricanes are so destructive and have big societal impacts, Trouet said. She anticipates the new findings will help improve future hurricane predictions under a changing climate.

###

121 thoughts on “Study: fewer Caribbean hurricanes during Maunder Minimum of solar activity

  1. How can this possible, since the LIA was just a regional phenomenon in Western Europe and maybe Greenland? What is it doing in the tropics?

    And how can the sun possibly be important to climate? I hope nothing bad happens to such heterodox authors.

    • Agreed. there are too many other unconsidered inputs that this ceases to be scientific. Sailors back then were not daft and would not have sailed if a hurricane threatened thus reducing risk of being sunk. History shows that colder climates bring bad weather.

      • Of course back then, they didn’t have satellite imagery. Hurricanes aren’t always visible from a distance, and they do tend to move around!

      • Sailors in smaller boats can tell which way the storm-driven swells are approaching – an art that allowed the Polynesians to navigate the open Pacific.
        Unfortunately today’s very large, powered ships are far less susceptible to the rocking due to ocean swells, and their sailors have lost this ‘weather sense.’

      • Tad,
        Yes.
        The modern fashion for enclosed Bridges exacerbates the problem.
        They need to be enclosed for the electronics, I am told; and I worry that [young] junior Officers of the Watch treat the whole voyage as a form of computer game.
        Even looking out of the window gets less attention – never mind ColRegs Rule 5.
        And no matter how big the ship, there is some weather that means you must slow down – or suffer the damage. Rule of Thumb – if it’s Beaufort 8 [Gale] or above, from four points on the bow through right ahead to four points on the other bow – think about slowing down.

        Auto

      • John — we have two quite recent counters to your assertion that “sailors are not daft and wouldn’t have sailed….” — one the cargo ship did sink with loss of all hands, and the other the passenger liner cut short its cruise with the passengers treated as “Bond’s Vodka Martini” — shaken not stirred

        These two examples occurred in a era of satellite nav, radar and satellite imagery as well as advanced weather system modeling

  2. The growth of trees is retarded in years with hurricanes….

    Pleeeze, the growth of trees is retarded in years that are very dry, it is retarded in years that are very hot, it is retarded in years that are very cold… about 40 years ago someone asked my father, who had been the Associate Dean for Research in the College of Agriculture at a major land grant university, (if I told you which one it would give away my identity, so place your guess here) … “what are the ideal growing conditions for corn?” My father’s response was: “If anyone ever figures that out I’ll let you know.”

    and they’re 100% sure that it was hurricanes?

    • ideal growing conditions for corn?
      Whenever the market price, less costs, will be higher than average. (what do I win?)

      • DonM, I think you win nothing.
        Whatever the market price, it still has to grow before it can be sold. The lowest condition for growth will limit growth regardless of the abundance of the rest of the conditions.
        The going market rate has nothing to with the growth, only the willingness of the farmer to invest in supplying the lowest condition….if he knows what it is.

        That’s where Mann was so wrong. He assumed that temperature trumped all else that affected tree-rings . (And he neglected to include all of the tree-rings available.)
        Yamal 06.
        What a tough life it must have had!
        Spurned by all the wolves.
        No rabbits or caribou would die and decompose near it.
        All the bigger trees wouldn’t let it get light!

        Perhaps it takes a perverted kind of solace in the fact that it’s made life tough for the rest of us.

      • I know, you are right. We were talking about two different things, of which neither has a valid answer. There is no ideal corn growth matrix, which makes it impossible to ideal for market profit either.

        (… and there is no ideal temperature and no real way to honestly or realistically look at cost-benefit with respect to that phantom ideal)

        Mark’s father was honest … too bad we don’t get that anymore.

    • BSME 1975, Purdue

      I was in the basement of big block building and thought I was safe from tornadoes. Thirty miles away a historic courthouse just up and disappeared into the funnel cloud.

      A good time to worry is when you think you are safe.

      • Not Florida; just the Florida Keys.

        There are a lot of folks living in Key West because they believe a majority of hurricane paths miss the keys.

        Then there is the alleged ‘ship departure and return times’. It did not take long before the great sea powers figured out the basic hurricane season and scheduled ship movements during what were considered safer times.

        There are too many assumptions going into this study.
        a) Florida tree growth rings are only affected by hurricanes
        b) Hurricane years are visible in tree growth rings; as in what is the proof?
        c) Ship manifests, routes and sinkings provide a consistent background for reliably estimating hurricanes and sunspots.
        d) That there is a proven connection between sunspots and hurricanes.

        “…Trouet and her coauthors hatched the idea for the study while sitting on the patio of Tucson’s Hotel Congress…”

        Is there a difference between porch swing or sofa based research?

        University of Arizona… Known for dodgy climate science…

      • “What about the Hurricanes that never made landfall in Florida?”

        Great question. My answer from Orlando is that if a cane don’t hit Florida then it does not exist!

  3. Hmmm… tree ring records for hurricanes? Now that’s interesting. I can see that it might work; limbs down and leaves stripped. It would make for a poor year for a tree that survived.

    • Tree gets whipped around … small roots get damaged?
      Significant salt added to tree?
      stunted from psychological damage (for the vegans that believe tomatoes and trees have feelings)?

      • All I could think of was leaf loss, if substantial enough, might cut the growing season off.

      • Certainly true – they didn’t even have tree psychologists back then! It’s a wonder all trees didn’t die of bi-polar syndrome.

      • Just how does one decide the difference between:
        a) Severe thunderstorms
        b) Tornadoes and waterspouts which are far more common than hurricanes and also accompany hurricanes.
        c) rodent damage to tree root systems
        d) drought
        e) insect infestations
        f) local tribes using a tree for their privacy while passing through

        Then there is second growth, when/if trees enter into a late year flush by actively growing new shoots and leaves. Much of Florida is semi-tropic and capable of year round growth. Florida is not Yamal…

      • Issues with salt would only matter within a few miles of the shore.
        Hurricanes have been hitting that coast for millions of years, it’s possible the trees close to the coast have evolved ways to handle small increases in salt.

  4. That sounds like – the more CO2 we have, the MORE PIRATES!

    I’m not sure if that proves Global Warming, or the Spaghetti Monster…

  5. How can that possibly be? Haven’t the “experts” been assuring us that the change in TSI is way to small to have any impact on weather or climate?

    • TSI is way to small
      ==============
      Ever amateur radio operator knowns that radio propagation varies greatly during the solar cycle, and this propagation is directly tied to solar activity.

      So it seems very strange that a radio can measure something that TSI cannot. Maybe solar scientists are using the wrong kind of ruler to do their measuring.

      • @ferdberple:
        The issue is in the definitions.

        TSI is a measure of near-infrared to near-ultraviolet light, since that is what is able to penetrate to the surface of the Earth barring cloud cover. This is where nearly all of the energy for the climate system is believed to come from, and yet from the height of the solar cycle to the lowest depths, this number varies less than the average 60W incandescent bulb in a 1st World house (by percentage).

        This is why the Sun was discarded for a long time as the source of short (i.e., decadal to millenial) climate changes.

        It is, by contrast, also true that the output of the solar wind and magnetosphere change dramatically from low to high in the average solar cycle, sometimes by several tens of percent! If one could somehow show how THAT energy was translated into the climate system (as opposed to the relatively sensitive HAM radio system, e.g.), we could all breath easy and join in the typical “It’s the Sun, Stupid!” chorus. Trouble is, there are no clear links, and the ones which may exist based on observations are tenuous at best.

        I’m sure lsvalgaard will expound as needed, since this is his area of expertise, for sure.

      • What the HAM radio system propagation depends on is atmospheric IONIZATION. The greater the ionization, the greater the reflection of radio waves back to earth, the further you can transmit and receive higher frequency SW radio signals (10-20 meters).

        Clearly there is a huge difference in atmospheric ionization between the high and lows of the solar cycle. Why does TSI not register this? It seems a very misleading measure as a result. Clearly it is not telling the whole story.

  6. It seems miraculous that some authors bothered to check climate proxies (shipwrecks and tree rings in this case) against each other. If only Michael Mann had bothered.

  7. Correlating tree rings with climate is a function AGW that just won’t die. As if every tree is placed in the same position and has the same access to sun, water, and nutrition. And is growing without regard to elevation or differing temperature regimes.
    Perhaps the number of shipwrecks could give us a clue, but that doesn’t tell us about the total number of ships at any given time, the time of year they were sailing, or the state of ships. How long were they in service? How did the captains get their commission, based on politics or merit?
    Maybe we could tell something about climate based on airplane crashes.

    • Indeed, we have periodic insect invasions roughly every 20 years when they eat EVERYTHING in the forest and then the trees have small rings due to this.

    • I thought the article mentioned that there was a good correlation between tree rings and hurricanes back to 1707 which was the beginning of the colonial era and there were Europeans in Florida making official records of when hurricanes struck land.

      • It’s a red herring type of article. Somebody in the CAGW field believes that skeptics are so dumb that we will latch on to any kind of research that sort of disproves CAGW by a failed method. The width of tree is/can be more accurately be affected by drought than by temperature. They know this. There was a research paper published in 1976 on isotopic information in tree rings that does match climate. For a group of people that claim they are scientists, why do you suppose they wrote this paper?

  8. “She anticipates the new findings will help improve future hurricane predictions under a changing climate.”

    I think weather satellites have improved predictions. Just saying!

    While working in China, three typhoons hit our living compound which was on the ocean with one road out. My wife was in bed with vertigo so I came home to fix her lunch. The weather was getting ugly so I checked the internet. A typhoon was coming so I headed for the store to make sure we had food for a few days without power.

    On the way back I bumped into the French doctor from the clinic. While discussing my wife, he received a text that the typhoon had been upgraded to one level below site evacuation. We decided it was time to get my wife to a specialist in Hong Kong.

    Sixty-five people perished 100 km down the coast. The excuse is always the same. It was the worst typhoon that anyone remembered.

  9. Counting on ship wrecks only may be misleading. A more complete account would be the percentage of ship crossings that ended in ship wrecks. Why? Spain faced a period of severe depopulation from the late 16th century and well into the 18th century. There could be less ship wrecks because there were less ocean crossings and has nothing to do with hurricanes. The English were gaining dominance of the seas because their population was growing.

    • Yeah, what if having the fewer wrecks was due to fewer ships sailing? Or better captains? Or a changes to navigational routes? Ships probably waited to sail until they had sufficient cargo, so no regularity there. If a ship didn’t arrive for whatever reason (hurricane, lack of funds, piracy, illness, mutiny, or whatnot), further shipments would have to wait on a new ship, which ought to skew the odds for a hurricane-induced shipwreck.

  10. This theory doesn’t fit well with records from Europe. The Great Storm of 1703 was apocalyptic.

    from Wiki
    In London, approximately 2,000 massive chimney stacks were blown down. The lead roofing was blown off Westminster Abbey, and Queen Anne had to shelter in a cellar at St James’s Palace to avoid collapsing chimneys and part of the roof. On the Thames, some 700 ships were heaped together in the Pool of London, the section downstream from London Bridge. HMS Vanguard was wrecked at Chatham. Admiral Sir Cloudesley Shovell’s HMS Association was blown from Harwich to Gothenburg in Sweden before way could be made back to England.Pinnacles were blown from the top of King’s College Chapel, in Cambridge

    The entire channel squadron of the RN was lost

    Daniel Defoe wrote in his book The Great Storm that “No pen could describe it, nor tongue express it, nor thought conceive it unless by one in the extremity of it.” Coastal towns such as Portsmouth “looked as if the enemy had sackt them and were most miserably torn to pieces.” Winds of up to 80 miles per hour (130 km/h) destroyed more than 400 windmills, in some the sails in some turned so fast that the friction caused the wooden wheels to overheat and catch fire.

    One individual story was that of a fishing boat off Devon caught in the storm that was eventually found wedged between tow pinnacles of the Needles Rocks off the Isle Of Wight, by some miracle the crew survived.

    • I bet some of the people who live in south-western Ontario wish a strong wind would blow down some of the windmills the Liberal government have erected practically in their backyards. The government currently allows wind companies like Samsung to place these 215m (700 ft.) tall behemoths as close as 550m (1/3 mi.) from homes.

      • as close as 550m (1/3 mi.) from homes.
        ================
        how many politicians have one in their backyard? Clearly the 550m limit only applies to the little people.

  11. l can see how this may have worked.
    The past has shown that during times of climate cooling North America is one of the areas that tend to suffer the most from this cooling. Which suggests that during climate cooling both Polar air and a more active jet stream gets pushed further to the south over North America. Now with both colder air and a more active jet stream been nearer the Caribbean. That would have likely made the atmosphere over the Caribbean more unstable. Which then may have lead to a increase in the amount wind shear over the Caribbean. So which in turn leads to a decrease in the amount of hurricanes forming in the Caribbean.
    lts just a idea?

    • The Subtropical jet stream produces the wind shear over the Caribbean not the Polar jet. The Polar jet acts as a steering force as storms approach North America. When it is further south the storms would probably veer northeast earlier. But that is after they leave the Caribbean.

      • Tom thanks for the reply.
        Yes its the Subtropical that flows over the Caribbean, but at times the Polar jet pushes so far to the south over North America that it joins up with the Subtropical and can even change its track. My point is that this would have happened more often during climate cooling, and this would have lead to a more unstable atmosphere over the Caribbean. So making it less suitable for the forming of hurricanes. Remember they are just talking about hurricanes in the Caribbean.

  12. I would research the Spanish Colonial Records for Hispaniola and Cuba too. Bet the authorities recorded hurricanes and reports of hurricanes.
    French, English and Netherlands records would be good too. Even Denmark was in the Caribbean.
    Written records would be easy and reliable if read.
    The last paragraph of the story is …well…”PC”.

  13. Why don’t we subject this study to the same level of scrutiny as the ‘Extreme Tornado Outbreaks Have Become More Common’ study?

  14. Riiiight … it is a spliced record, and the anomalous period is right before the splice. Not only that but the puff piece above is pre-publication, so they get to put their claims out there with no chance of anyone even reading their study, much less falsifying it, until after their version has gone round the world. No data, no code, no methods section, no nothing.

    Sorry, but to me that’s scientific malfeasance. I’ll remember the names of the authors so I can avoid them in future.

    w.

    • Well, further research reveals that the editor of the piece was Kerry Emanuel … that explains a lot.

      w.

      • AC,
        Oliver Heavyside did not have much of an establishment C.V. either. I also remember some of my highly credentialed profs saying that continental drift was B.S.

      • ‘Alan Cates’ asked for “just one” research result that had any impact on climatology.

        Willis Eschenbach’s ’emergent phenomena’ of tropical thunderstorms drew hundreds of comments, many from well known folks with advanced degrees in the hard sciences, so obviously it had an impact. Just like his dozens of other science articles posted here over the years. Just put ‘Eschenbach’ into the search box for a week’s worth of interesting and informative reading.

        Now I have a question: why the hatred and animosity? Is it green-eyed jealousy? Is it your inferiority complex? You sound just like another loser who hides behind fake screen names here. Izzat you, 1oldnwise/’Cates’?

      • Willis, the work has been peer reviewed. It cannot be wrong. It is physically impossible. The gods have spoken. One might as well question the Pope. It has all been handed down from Zeus on Mount Olympus. It cannot be wrong,

      • “Your inability to provide a single “result” shows how much “impact” the blogger has.”

        In the area of AGW vs. NGW, the bloggers of the latter have been far more effective in swaying pubic opinion than the bloggers of the former. Since the debut of this website, I have shared what I’ve learned with scores of students who now have a more ethical approach when developing software than the programmers at CRU.

        (Yes I know that W.E. was being referred to specifically.)

      • For some reason, certain people attract trolls who’s sole purpose in life is to follow them around trying to convince everyone that the person is not worth attention.
        AC seems to be Willis’s.

      • We had an article on scientific elitism just a few days ago.
        AC demonstrates that article perfectly.
        Unless Willis has articles in it’s preferred journals, than Willis isn’t a scientist and everyone should just ignore him.

        It really is sad the way so many people substitute credentials for credibility.

    • Nothing to do with my inability.

      Do a bit of your own research then talk about “impact” or lack thereof.

    • Alan cates:
      Why the focus on Willis’s CV?

      What part or point of Willis’s comment is wrong?

      The news release is a definitive and typical climate approach to science; i.e. science by PR announcement.
      No data
      No code
      No replication
      No verification

      Whether your idol or whether you answer the obvious weaknesses of the above announcement is immaterial. The science stated, that your idol participated in, is all imaginary. Where are the proofs?

      Many people here would especially like to know how Florida tree rings can explicitly show hurricanes, as opposed to severe thunderstorms, tornadoes, waterspouts, tsunami, droughts, insect infestations, and so many more.

      It would be very intriguing to know how ships that explicitly sailed outside normal hurricane seasons; when sunk, provide evidence for hurricane numbers?

      Or how silt layers in the Florida Key’s provide any evidence for hurricanes in Florida? Or how silt layers prove hurricanes period; for all we know the silt layer could be built up by fish nesting, gators nesting, birds wallowing, or so many other of life’s interactions.

      the PR announcement above is a disgrace to science, pure and simple. That is what Willis conveyed. Yet you have instead resorted to personal attacks, not science. Typical useless CAGW disciple, all preach and castigation, no science.

      • Really?

        Where did Willis ‘attack’ Emanuel? By stating that he ‘that explains a lot’?
        That wasn’t an attack; so get over it and stop using false reasons to attack Willis.

        But you, Alan, have agreed with everyone here, including Willis, who knew exactly what Willis meant.

        So when is your ‘Emanuel’ idol going to work on earning respect for his science and strict scientific methods? Blind worship from groupies just ain’t useful.
        Assumptions ≠ Science
        Correlation ≠ Science, especially dreadfully weak correlations

    • Steven Mosher,

      I’ve always been polite to you. Too bad you won’t do likewise. Also, I have never sockpuppeted my name. Never. Sockpuppetry is when you use multiple screen names simultaneously, like ‘1old…’, and the many other sockpuppet screen names that ‘Cates’ uses at the same time, pretending that his views have more support than they do. In reality, he’s just one disgruntled commenter who can’t support his belief system, so he has to invent fictitious support.

      And yes, I changed my screen name when Anthony started referring to fake names like ‘1old’ as anonymous cowards. After that I just switched to using my name. So your implication is false. But I know better than to expect an apology from you.

      Finaly, I note that ‘1old’ is now using ‘Alan Cates’ as his sockpuppet identity, which he stole from the real Alan Cates. He refuses to answer my question, even though I’ve answered his. I know his real identity, and I know why he is an anonymous coward. I know more about him than he thinks I do.

  15. A hurricane can be the best thing to ever happen to a tree, and need not be reflected as a narrower ring. I large, old, and beloved red oak tree fell last summer at the YMCA camp in New Hampshire where my family has gone for many years. I wrote an “obituary” of sorts for that tree a few months ago that included a review of the rings. The Hurricane of 1938 was a direct hit. The surrounding pines were wiped out and suddenly the oak tree had all of the light and water it needed for maximum growth. Call me skeptical. You can read the story here: http://ymcaboston.org/sites/default/files/file_uploads/grains_of_sandy-waterfront_tree.pdf

    • The abstract says:

      “We find a 75% reduction in decadal-scale Caribbean TC activity during the MM …”

      Given known historical variations, that seems way, way too big.

      w.

      • IIRC, Soon & Yaskell (2003) found more rather than fewer TCs during the MM. This IMO would be more in line with expectations, as a cooler world ought to be stormier. There could however be countervailing factors.

        Could be that the Spanish just gave up sailing during the active hurricane seasons during the depths of the MM, which if so should be reflected in their records. Historical documentation is useful in climatology.

  16. There will be no ships lost to hurricane shipwrecks if there are no ships sailing. During that period the New World was vital to Spain’s economy however and the gold from Peru was essential to pay for the Spanish military adventures. Thus the ships were under Royal pressure to sail. It is also a given that no sailing master will sail directly into a hurricane if avoidable since it is reasonable to assume they were not suicidal. And the captains certainly knew the season when the hurricanes were likely.
    It is also true that, in order to avoid being pirated along the way by the many enemies of Spain, it was necessary to sail in fleets, often with naval protection. It is often impossible to delay a departure of many ships until potentially dangerous conditions abate so, under orders, the captains sailed anyway (fleet admirals are not necessarily the best sailors).
    The result is a statistical phenomenon where ships can wreck in bunches because they all sailed in deliberate proximity and with resultant poor maneuverability. It is not clear from the summary presented that these anomalies are adequately accounted for. ie For these reasons it is MUCH riskier to sail bunches of ships in hurricane season than sailing singly.

    • NW sage says, ” it was necessary to sail in fleets”.

      This is statistically important, because for unbiased results, “statistical events” should be independent. If the independent events for this study should have been “fleets” (each comprising one or more ships) and not “ships”, that might have introduced bias into the study. However, the authors state that Spanish shipping was merely the inspiration for the study. Based on the proxies they used rather than on Spanish shipping, their conclusions seem robust.

      The same problem in defining “independent events” applies to estimating risk of fatality in vehicle traffic. The event should be the “vehicle trip”, not “passenger trip”. The potential for bias is related to the number of passengers per vehicle. (Less bias for cars than for buses because the ratio of ‘passenger to vehicles’ is lower.)

      Commercial aircraft contain so many passengers that the least biased measure of air safety relies on “aircraft movements” (specifically takeoffs). The reasoning is that “aircraft movements” define independent events better than “passenger trips”. (The rueful expression, ‘We are all in the same boat’ captures the essence of the risk.)

      Finally: If solar activity could so influence tropical cyclones over such a long time period, could it be that the Modern Warm Period is merely recovery from the Little Ice Age, warming having resulted from increased solar activity, not mostly caused by humans?

  17. If I was in charge of the Spanish Treasure Fleet I’d get tired of losing ships, crews and cargoes. So, I’d issue an edict: no sailing from mid-August to mid-October. By simply avoiding that period I’d cut my losses by two-thirds. Problem solved.
    So, I wonder if the study took into account changes in sailing schedules. I imagine that the Spanish were capable of learning and adjusting, and did so.

    • Good point, but sailing dates and routes were constrained by prevailing winds, which vary seasonally. Your idea does indicate a possible way to assess the methodology used in the study.

    • From wikipedia..

      “The 1715 Treasure Fleet was a Spanish treasure fleet returning from the New World to Spain. At two in the morning on July 31, 1715, seven days after departing from Havana, Cuba, eleven of the twelve ships of this fleet were lost in a hurricane near present-day Vero Beach, Florida”

      Plus the, at that time usual,l inconvenience of English, Dutch and French privateers and pirates at all times of the year

  18. Lordy. This is the worst kind of research. Find something over here, that happens during something over there, and then suggest cause and effect. Back when a short redheaded Irish lass could live in a cave and be a goddess priest who could predict that right after she woke up the Sun would rise is the equivalent to this piece of garbage science. And BOTH asked for more coinage on your way out the door!

  19. Am not so quick to dismiss this study as some on hear are, as l can see there could be some truth to it.
    A colder climate in North America would have had an effect on conditions in the Caribbean. As its highly likely that the jet stream would have been more active and pushed more to the south then it does now.
    So the chances of it having a effect on the atmosphere over the Caribbean would have been greater. And one of these effects would surely been a increase in the amount of wind shear. Which reduces the chance of hurricanes forming. l think there is a case for further study of this idea.

    • I agree. While Spanish shipping may have inspired the study, it is not the main empirical basis for the authors’ claims . It is possible to be right for the wrong reasons. (cf. Wegener and continental mobility.)

  20. Having better predictions about how anthropogenic climate change affects hurricane activity is important because hurricanes are so destructive and have big societal impacts, Trouet said.

    How on Earth does an alleged Maunder Minimum effect relate to anthropogenic climate change? What, Man will now trigger a Maunder Minimum?!

    • Yup.
      The only way to save ourselves is to reenergize the sun, by firing shiploads of climate scientists into its core.
      Especially scientist of the quality that produced this study.

      • firing shiploads of climate scientists into its core
        =================
        the EPA will outlaw this. it is the worst form of carbon pollution.

  21. Historical records appear to indicate that convoy sizes halved from it’s peak, earlier in that century at 50 odd ships per convoy, by the mid 1600’s and did not pick up again until early 1700 all due to cooling economic conditions in Spain. Coincides nicely with the findings of above study but of course correlation etc. Seeing the Spanish were so good at record keeping (supposedly as per above) surely someone writing the above report would have noticed the reduction in convoy sizes rather then just a reduction in ships lost. But when the search is selective one could miss certain related data.
    One can, possibly more accurately, conclude that the MM caused the economic hardship and as such the reduction in shipping leading to the reduced losses due to hurricanes. Which is not the same as saying that there were fewer hurricanes during the MM.

  22. The study assumes that people during that period were not better at avoiding hurricanes than at other periods. Perhaps one group got an education or experience which were more relevant to sailing.

  23. After Medina Sidonia’s not so excellent adventure of 1588, things did not go well for Spain. Many ships were lost, many sailors were lost. The depredations of Drake and Morgan, did not help with the rebuilding the Spanish fleet.
    I wonder if the trade winds decreased or increased during the Maunder Minimum, as that would have had an impact on sea voyages at the time.

  24. Although global climate models indicate hurricanes will be more intense as the climate warms, those models are not yet good at making regional predictions, Trouet said.

    Well if the models cannot predict hurricanes on a basin by basin ‘regional’ level why would we have any faith in what they show as a global average.? Tropical storms are emergent phenomena which spring up out of variations in local ‘regional’ conditions.

    If you can’t model that you can’t model hurricanes, period. You model is WORTHLESS. Come back when you have a model that works.

    Anyone looking for naive linear relationship between tropical storms and global average temperature has zero understanding of climate and weather.


    https://judithcurry.com/2016/01/11/ace-in-the-hole/

    When their GCMs can reproduce the drop off of cyclone energy since 2005 and during the mid-century warm period they may have something to tell us.

  25. “We’re providing information that can help those models become more precise,” she said.

    We are now living in the hottest period EVAH and have a trough in hurricane activity. Models say is should be at a max. Becoming “more precise” than that should not be difficult.

    The stupid language tries, dishonestly, to pretend that models are already “precise” but just need a bit more input from sunken spanish ships to tweak then into being “more precise”

    The models are diametrically WRONG for the current period. That is not a degree of precision.

  26. This is proof positive that when there is a Maunder Minimum, there are more pirates about, as fewer of them go to Davey Jones’ Locker.

    • Good point, Maybe the recent drop in solar activity explains the increase in piracy of the Somali coast !

  27. Learning that a lull in Caribbean hurricanes corresponded to a time when Earth received less solar energy will help researchers better understand the influence of large changes in radiation, including that from greenhouse gas emissions, on hurricane activity.

    Says who?
    There is the spurious assumption that IR that affects a few microns of the surface has the same effect on SST as UV that penetrates tens of metres.

    Do they even think about physics before writing such garbage?

  28. Harley mentioned he had tree-ring records from the Florida Keys that went back to 1707 – and that the tree rings revealed when hurricanes had occurred. The growth of trees is retarded in years with hurricanes. That reduction in growth is reflected in the tree’s annual rings.

    Isn’t it great how tree rings are just like tea leaves ?

    All you have to do is concentrate really hard on the thing you want to know about and tree-rings will give you the answer.

    You then totally ignore all the other things tree-rings are also claimed to indicate any you have proxy result.

    MAGIC isn’t it?

    • I love then hand-waving explanation for the proxy. Never mind doing a study to establish the proxy relationship before doing a study based on the proxy. Just assume it is a reliable proxy if it gives the answer you want.

      Once your dressed it up with a few words like “societal impact” and “anthropogenic climate change” and it’s sure to get published.

      You’re in !

  29. http://link.springer.com/article/10.1007/s10933-015-9861-3
    [W]e reconstructed the history of typhoon and storm-rain activity only for the interval AD 1400–1900. The record indicates that typhoon frequency throughout the Korean Peninsula varied in response to the state of the El Niño/Southern Oscillation. Typhoon variability was likely modulated further by the state of the East Asia summer monsoon (EASM) pattern, associated with variation in the magnitude of solar irradiance. During periods of minimum solar activity, such as the early Maunder Minimum (AD 1650–1675), typhoons struck the east China coast and Korean Peninsula more frequently because of a strengthened EASM.

    http://link.springer.com/article/10.1007%2Fs00382-010-0883-2
    The linear trend in the number of severe TCs [tropical cyclones] making land-fall over eastern Australia declined from about 0.45 TCs/year in the early 1870s to about 0.17 TCs/year in recent times—a 62% decline.

    http://linkis.com/wiley.com/lXQQS
    Our record of tropical cyclone activity reveals no significant trends in the total number of tropical cyclones (tropical storms and hurricanes) in the best sampled regions for the past 318 years. However, the total number of hurricanes in the 20th century is ∼20% lower than in previous centuries.

  30. Apologies for this OT comment, I’m having difficulties getting the tips and notes page to load. I was just wondering if this article from the Conversation has been mentioned here yet?

    ‘We traced the human fingerprint on record-breaking temperatures back to the 1930s’
    “In recent years climate scientists have looked at the role climate change played in unusual extreme weather events such as Australia’s hottest summer in 2012-13 and recent heatwaves.
    Before now no one had looked at how far back in time we could go and still link these weird weather events and record-breaking climate extremes to our influence on the climate.
    Our study, published in Geophysical Research Letters, addressed the question of when climate change started altering the influence of record hot years and summers in a way we can detect. We looked at five regions of the world, as well as the whole globe.
    We’ve been changing the weather for a long time
    Human-made climate change has been influencing heat extremes for decades, with many past records directly attributable to the effect we have had on the climate…”
    https://theconversation.com/we-traced-the-human-fingerprint-on-record-breaking-temperatures-back-to-the-1930s-55438
    The paper is paywalled
    http://onlinelibrary.wiley.com/doi/10.1002/2015GL067448/abstract

  31. “Harley mentioned he had tree-ring records from the Florida Keys that went back to 1707 – and that the tree rings revealed when hurricanes had occurred.”

    But that is only the time period that covers the last 18 years of the this, 70 year period mentioned in the “study”:

    ‘Records of Spanish shipwrecks combined with tree-ring records show the period 1645 to 1715 had the fewest Caribbean hurricanes since 1500″‘

    Talk about cherry picking.
    And can tell some-one tell me? What is with this ad hominum attacking on WE by Alan Cates? Mr. WE has provided many (to me and others) excellent LOGICAL hands on articles on thunder- storms , cloud development in the tropics and again HANDS on experience of working on and with the sea, from the arctic to the tropics. Frankly I doubt that any of the “writers” of this “study” has ever set foot on a vessel further off shore than the middle of a 100 ft wide pond.
    ( some where on another thread somebody made the reference to a Brit that said something along the line of ” You can captain a ship at sea but you can run a Navy from behind a desk” That is very apt.
    To me the amount of experience that Mr. E gathered all the years he actually worked in those environments and has been able to write understandable, logical records of those years compared to someone that spends 6-8 years sitting behind a desk in a university followed by a few more years behind a desk studying models rates just a wee bit higher in my HO. but then who am I? And thanks for the rant. good night from chilly Canada. ( which for this time of the year is quite normal, it isn’t even spring yet!).

    • You mean like Capt. Edward Teach, aka Blackbeard? Who ran his ill gotten ship ‘Queen Anne’s Revenge’ aground off of Beaufort island.

      • That was in 1718, so after the MM is generally considered to have ended. A common end date is 1715, but its depths were in the 1680s-90s.

    • Thanks for the link, Geoffrey Preece. I’m off to work, but from a quick read, it looks like hurricanes might register in tree rings. I didn’t get to any error estimates yet, where they examine tee rings that give a false positive for hurricanes.

      Thanks again.

    • “…Suppressed growth patterns were noted in cores collected from all but two control sites. In particular, there were rings missing for years immediately following hurricane Camille. Several innovative approaches were used to determine whether the timing of a hurricane was coincident with changes in growth pattern. These detection methods included repeated measure analysis of growth rates before and after the hurricane, differences in within-tree stemwood distribution, and growth departures from expected biological growth. All site collections demonstrated some growth sensitivity to one or more hurricanes with one or more of the above analytical approaches…”

      Reads like they were darned determined to link hurricane to growth rings, reasons be dam_ed. That last sentence above is especially telling.

      “…rings missing for years immediately following hurricane Camille…”, rings missing entirely, for years? Perhaps because of bark loss?
      Bark loss is not restricted to hurricanes.

  32. I once read the hypothesis that a colder average temperature for the planet meant that the difference in temperature of the poles and the equator was less. In other words, than the temperature differences were reduced. It has been speculated that it is temperature difference that leads to a lot of weather impact and that a lesser difference would lead to a calmer weather in general. (not better, as warmer is better for life)

    This paper seems to be saying much the same it looks like at first glance.

  33. I see that in the press release they claim:
    “Although global climate models indicate hurricanes will be more intense as the climate warms, those models are not yet good at making regional predictions, Trouet said.”
    What they don’t mention is that the GCMs indicate only about a 5% increase in strength, but many also indicate a substantial DECREASE in overall tropical cyclone numbers. The warmunists keep fudging on this and the IPCC tried to bury this in its AR5. Imagine how the public would react if someone were to mention that the global climate models were predicting a decrease in hurricanes in a warmer world.

  34. The hurricane/tree ring connection looks plausible to me. I checked their supplemental data on specific years of suppressed growth vs. storms in the Florida Keys and it looks correlated to me. And it makes sense – Keys trees damaged by storms, both from wind and the salt from storm surge, take a year or so to recover.

    The one thing I’m not clear about is the timing – hurricanes occur at the end of the growth season, I believe, and so should affect the following year, not the current year. Their lag-1 data shows that delay but not their lag-0.

    I don’t see using shipwrecks to establish hurricane frequency. There are too many variables in shipwrecks. I looked for commentary in the paper by a professional historian but did not see any.

    • Thanks for that, David. I got a copy of the paper, lots of strange stuff. All of the data is available in the Supplemental Information online, but the paper talks about the methods. I’ll probably write something up on it, but the TLDR version is that it doesn’t hold up.

      w.

  35. Surely we can do better than tree rings and shipwrecks for regional climate measures. Drill some coral reefs, karst features, or maybe Miami beach for some data.

  36. It is funny how every new finding can improve the settled science of climate models.
    If you counts all the improvements possible for climate models they must be in a very infant state, especially as it is believers that say it..

  37. How could this study have any credibility at all? None of the authors are from Harvard or Yale.

  38. Major problems with this.
    a) The bulk of negative NAO in Maunder was 1672-1705, the 1650’s and 1660’s were largely very warm in NW Europe.
    b) Increased negative NAO leads to a warm North Atlantic (AMO), as from 1995 and from 1925, and through the last solar minimum in the late 1800’s.
    c) The weakest solar magnetic phase of the Dalton Minimum through 1807-1817 saw an increase in Caribbean tropical cyclones, along with a noted southward shift of the ITCZ.
    d) The big change in solar activity through solar minima is the solar wind strength rather than irradiance.
    https://en.wikipedia.org/wiki/1800%E2%80%9309_Atlantic_hurricane_seasons
    https://en.wikipedia.org/wiki/1810%E2%80%9319_Atlantic_hurricane_seasons

  39. There is now a shipwreck in Arizona — the remains can be seen at the university. No recovery possible.

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