Hurricane frequency is up but not their strength, say Clemson researchers

From a Clemson University press release, another peer reviewed study refutes the “global warming to hurricane” linkage that supposedly is causing stronger storms.

The increasing frequency of storms in the last 50 years is to be expected, due to better reporting and improved technology like satellites, Hurricane Hunter planes, and Doppler Radar. NOAA agrees on the improved reporting issue in a study here.

This echoes what I reported on April 11th 2008 about Emanuel’s findings as well as what I reported on February 21st 2008 from Roger Pielke Jr. and Chris Landsea at the National Hurricane Center. On May 15th, 2008, Tom Knutson, a meteorologist with the National Oceanic and Atmospheric Administration’s fluid dynamics lab in Princeton, N.J. reversed his position on the issue in an AP story and argues “against the notion that we’ve already seen a really dramatic increase in Atlantic hurricane activity resulting from greenhouse warming.”

Plus, according to Florida State University’s Ryan Maue,  Accumulated Cyclone Energy has hit a 30 year low. The Global Warming  linkage simply isn’t there.

This graph shows the number of tropical cyclones (hurricanes plus tropical storms) that have been observed since 1850. Image by: Robert Lund, Clemson University

CLEMSON — 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.

Robert Lund, professor of mathematical sciences at Clemson, along with colleagues Michael Robbins and Colin Gallagher of Clemson and QiQi Lu of Mississippi State University, studied changes in the tropical cycle record in the North Atlantic between 1851 and 2008.

“This is a hot button in the argument for global warming,” said Lund. “Climatologists reporting to the U.S. Senate as recently as this summer testified to the exact opposite of what we find. Many researchers have maintained that warming waters of the Atlantic are increasing the strengths of these storms. We do not see evidence for this at all, however we do find that the number of storms has recently increased.”

The study represents one of the first rigorous statistical assessments of the issue with uncertainty margins calculated in. For example, Lund says “there is less than a one in 100,000 chance of seeing this many storms occur since 1965 if in truth changes are not taking place.”

He adds, “Hopefully such a rigorous assessment will clear up the controversy and the misinformation about what is truly happening with these storms.”

The study, submitted to the Journal of the American Statistical Association, also found changes in storm pattern records starting around 1935. This was expected at the onset of aircraft reconnaissance, which allowed record-keepers to identify and document storms occurring in the open ocean.

While the study did conclude that more storms are being documented, researchers found no evidence of recent increases in U.S. landfall strike probability of the strongest of hurricanes. Lund notes that “because these types of storms are so uncommon, it will take many more years of data to reliably assess this issue.”

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mark twain
September 25, 2009 1:29 am

why should we know, how many tropical cyclones did realy exist at 1900, or 1880 or 1930?
if there is a linear trend from about 8 in 1880 to 10 in 2000, so there is never any statistical signifikanz. all this studies are as dump as studies for sea ice aerea limits at 1800 or. 1900 an comparisons to moedern satellite datas. its nonses, maximal poorly estimates.

Ulric Lyons
September 25, 2009 1:31 am

US landfall:
Last 50yrs 76 events, previous 50yrs 97 events.

September 25, 2009 1:37 am

“The study represents one of the first rigorous statistical assessments of the issue with uncertainty margins calculated in. For example, Lund says “there is less than a one in 100,000 chance of seeing this many storms occur since 1965 if in truth changes are not taking place.”
I shall savour that as a perfect example of the genre. Has a poetic quality, doesn’t it? Lewis Carroll would have been proud.

September 25, 2009 1:41 am

The tropical cyclones are observed by satellites for 40 years.
Before that, how many others have been lost to observers because they haven’t reached the shores or ships at sea ?

King of Cool
September 25, 2009 3:10 am

Well even the BOM which is more leaning towards AGW stated the following in 2006 as regards frequency:
The paper reaffirms the finding of a 1998 study saying that any change in the frequency of tropical cyclones (hurricanes/typhoons) due to climate change cannot be determined due to a lack of knowledge and limitations of the available observing technologies. The little evidence that does exist indicates little or no change in global frequency.
And as regards intensity:
It also says that while some recent studies have suggested the intensity of tropical cyclones (hurricanes/typhoons) has increased substantially over the past 50 years due to climate change, the scientific community is “deeply divided”. Some researchers believe the climate record is too inconsistent to draw such a conclusion due to changes in observations equipment and methods over time. The panel says it cannot come to a definitive conclusion in this “hotly debated area”.
Homo praesumitur bonus donec probetur malus?

September 25, 2009 4:21 am

Re Ulric Lyons (01:31:41)
Thank you, a very cogent link, sorta removes the different observation capacity delima over the period of study.
Should not a “professional study” answer such a question, How can the number of US landfall hurricane’s go down, why the number of reported huricanes consistently increases. Instead they note that there is no indication that US land fall will increase, ant take the increase without discussion and statististical anaylisis of how new technoloy development and implementation of said technology, would impact the chart they headline.

Patrick Davis
September 25, 2009 4:36 am

“King of Cool (03:10:49) :
Homo praesumitur bonus donec probetur malus?”
Can I have that in proper POHM England please?

Kevin Kilty
September 25, 2009 5:01 am

Take the annual numbers of hurricanes in the Atlantic of category three or greater since 1944, and assume a Poisson distribution with a secular, linear component of the expected annual number. Perform a maximum likelihood estimate of the “slope” of this secular term, and what you will find is a tiny positive value that is most probably below any statistical significance.
Possibly the incidence of typhoons in the Pacific or Indian Oceans has increased. I don’t know for sure, I haven’t looked at the data. Possibly it is true as well that if one includes the annual count of minor hurricanes of category two and lower in the Atlantic then one might see an increasing incidence. However, in this last case, the example of this 2009 season and the impatience which hurricane meteorologists displayed in naming tropical storms and hurricances, one could propose that increasing incidence of minor storms has more to do with biases on the part of scientists and government agencies than it has to do with changes in instrumentation.

September 25, 2009 5:02 am

Our local forecasters spin the globe all the way over to the coast of Africa to have anything interesting to say. And then they focus on what “might happen” but never seems to happen.
And then they head over the Pacific to Asia, trying desperately to find something to talk about.
Once a cold front makes it past Tampa, the hurricane season is done.

Rick, michigan
September 25, 2009 5:17 am

So let me get this straight…more hurricanes, but no increased chance of hurricanes hitting the US.
Wouldn’t like playing marbles, and saying that I can put more marbles in the ring but not have a better chance of marbles going out of the ring, or that flipping more coins won’t increase the number of tails flipped?

September 25, 2009 5:26 am

‘For example, Lund says “there is less than a one in 100,000 chance of seeing this many storms occur since 1965 if in truth changes are not taking place.”’
Are there any English speakers out there? He’s not talking about storm reporting changes, he’s saying that since 1965 the earth IS warming so hurricane frequency IS increasing. Or Global Warming = More Hurricanes.
This is in direct contradiction to Ryan Maue’s work stating that frequency is dropping. “global-warming-more-hurricanes-still-not-happening”
This supports Joe Romm’s argument, why are you all cheering about it?

September 25, 2009 5:31 am

There could be an unseen force working to increase the frequency of storms. Should there be an increase in the number of named storms and the number of hurricanes, the calculation of insurance risk will increase. It is to the benefit of insurance companies to demonstrate higher risk from storms due to the statistical number of storms recorded and thus charge their customer a larger premium.
The pressures on the National Weather Service to name every tropical system a storm and to classify every possible storm a hurricane cannot be measured through collected data.

Steve M.
September 25, 2009 5:36 am

I’ve come to the conclusion that we can never win the AGW argument:
More hurricanes = AGW caused because of warmer waters
Less hurricanes = AGW causing more wind shear, stopping the formation of hurricanes
rising temps = AGW, well that’s what it’s all about
declining temps = AGW, it fits in the model and part of the overall trend
decreasing ice = AGW melting all the ice
increasing ice = AGW causing more precipitation thereby increasing ice
droughts(decreased precipitation) = AGW
Floods(increased precipitation) = AGW
Really, how can you fight an all encompassing theory? /sarc off

Steve M.
September 25, 2009 5:41 am

kind of ironic too that they publish this study in a year that we have had only 2 hurricanes.

Jeff L
September 25, 2009 6:00 am

Hmmmm…. I would be interested to here more on how they constructed the pre-satellite era record as the two different records would obviously give an upward bias. Given that this is written by statisticians, I would guess they have some reasonable logic. I would be really interested in Steve McIntyre’s take on this paper

Frank K.
September 25, 2009 6:00 am

It is always useful to review how the “experts” have performed in their previous forecasting efforts:
Date: 24th March 2006
“Atlantic hurricane frequency and intensity will remain elevated for at least the next five years.”
Risk Management Solutions (RMS) has announced that increases to hurricane landfall frequencies in the company’s US hurricane model will increase modeled annualized insurance losses by 40 percent on average across the Gulf Coast, Florida, and the Southeast, and by 25-30 percent in the Mid-Atlantic and Northeast coastal regions relative to those derived using long-term 1900-2005 historical average hurricane frequencies.

Expert panel convened
The RMS medium–term view of hurricane activity was developed in cooperation with a panel of leading experts in hurricane climatology convened by RMS in October 2005, including Dr. Jim Elsner, Professor in the Department of Geography, Florida State University; Dr. Kerry Emanuel, Professor in the Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology; Tom Knutson, Research Meteorologist, Geophysical Fluids Dynamic Laboratory, Princeton University ; and Dr. Mark Saunders, Professor of Climate Prediction, Department of Space and Climate Physics, University College London.
Based on the five-year perspective of this expert panel, RMS developed a methodology to update activity rates in its proprietary models based on storm intensity, storm track, and landfall region. This methodology indicates that increases in hurricane frequencies should be expected across the entire US coast, but will be highest in the Gulf, Florida , and the Southeast, while lower in the Mid-Atlantic and Northeast.

So – how’s the 2009 hurricane season going??

Ulric Lyons
September 25, 2009 6:02 am

David (04:21:43) :
“Re Ulric Lyons (01:31:41)
Thank you, a very cogent link, sorta removes the different observation capacity delima over the period of study.
Should not a “professional study” answer such a question, How can the number of US landfall hurricane’s go down, why the number of reported huricanes consistently increases.”
With a $100,000 grant from the National Science Foundation, one would hope for some answers.
How many landfall events of category 1 or above did not get reported in the last 100yrs or so? very few if any. For hurricanes in mid ocean, modern observations would record higher numbers.
The last 50yrs have had 26 category 3 and above US landfall, the previous 50yrs had 39. I finished that tally in 2min 36sec, now that would be a good hourly rate if I was on their money!

September 25, 2009 6:06 am

AGW promoters are scrambling to distract people from the ridiculous Manniac style, while staying with orthodox climate hype.
And failing.

Bill in Vigo
September 25, 2009 6:13 am

Over the years I have noticed that as the AGW movement has grown in intensity there has been a greater hype in the push to prove that catastrophic weather has happened. Much of this has been pushed by such as “The Weather Channel”. While I do watch “The Weather Channel” I do so with a grain of salt. This has happened in recent years and I believe has more to do with the political bent of the now owners of the program. There is also the proposition to sensationalize to increase market share to increase revenue. This has happened with all news reporting agencies especially the television markets. Having lived in the Gulf states, Florida 37 years, Alabama 12 years, and Mississippi 10 years, have seen the detection of these storms become increased over time. It is no wonder that the incidence of reporting has increased but from living in areas prone to the land fall of these storms I see no increase in the overall strength of the storms. In my humble poorly educated opinion this study is only expressing what should be obvious to most that follow the occurrences of these storms in the Atlantic basin. I heartily agree with the findings of this study.
Bill Derryberry

September 25, 2009 6:42 am

In this article:
Lund indicated the observational bias that has lead to more observed storms:
“Lund says the increase in the frequency of hurricanes and some measurable increase in strength of the storms was first observed from data from the beginning of the 20th century. Lund attributes the observations from better and more sophisticated technological devices used to monitor the storms. “We saw them from about 1900 which makes sense because most of the data recorded before 1900 was guesstimated and not very consistent. We also found small changes in the strengthof the storms around 1960 which coincides with the onset of satellites.”
Why do all the alarmists completely ignore the obvious observational bias?

Robert S. Gaza
September 25, 2009 6:42 am

Note that the graph only records storm frequency through 2005. The average number of Atlantic storms has dropped off the last 4 years…including this year which has been unusually quiet….despite forecasts to contrary. I’m glad to see that the authors haven’t resorted to tracking named storms as many do who track storm frequency. The definition has changed this decade to now include tropical depressions…skewing the later years to a higher frequency of named storms, everything else being equal.

Jeff Alberts
September 25, 2009 6:54 am

Even if the Atlantic is getting warmer, it’s simply not possible to have been caused by atmospheric CO2 concentrations.

September 25, 2009 6:57 am

Shouldn’t wind shear be considered as a factor in this, since it can weaken, as well as destroy, a hurricane? As from Saharan winds…or related to an El Nino event.
And, what about the fundamental as-seen-on-tv hurricane track coverage…
‘the hurricane will strengthen as it crosses this area of warmer water.’

Jeff Alberts
September 25, 2009 7:02 am

Patrick Davis (04:36:45) :

“King of Cool (03:10:49) :
Homo praesumitur bonus donec probetur malus?”

Can I have that in proper POHM England please?

Dude, just Google it.

September 25, 2009 7:05 am

How hard is it for people to understand that the tropical cyclone frequency record is not reliable for trend analysis? Did these guys read the recent literature at all?
I’m sorry, it is important that they did an analysis of the strength of storms, but they apparently do not know the issues with the counts. A good place to look is:
At any rate, there has not been any global increase in frequency, which one would think matters in “global warming”.

Tim Clark
September 25, 2009 7:05 am

This can’t be correct. Mann and his foggy bottom bog boys determined something else from three sediment deposits. /sarc

September 25, 2009 7:10 am

Its beginning to make me sick ….. the blatant mis-utilisation of fancy scientific words and fancy statistics to make something out of NOTHING. How can anyone possibly make a graph that stretches back 150 years and make it look like the uncertainties at one end are the same as the uncertainities at the other. Of course there were less observed storms earlier … there was less observation. Its pathetic.
The great thing about comparing landfall events of major storms is that there is a genuinely good chance that all major storms that actually hit land were reported in some scientific manner or other over the last 150 years. And a comparison of THAT shows absolutely nothing in terms of any increasing trend. If anything, it shows that previous decades has more storms.
Its pathetic.

September 25, 2009 7:21 am

It is great that real statisticians are looking at the data. Now, if we could only have somebody who could write/speak simple declarative English, we might know what the hell was going on.

jack morrow
September 25, 2009 8:03 am

Yesterday I thought I might get sick. After reading this I did.

September 25, 2009 8:05 am

Uh oh. Jaxa shows Artic sea ice leveling off or on a slight downturn. Levels seem headed toward the 2007/2008 trend lines. Perhaps those sunspots are already having an effect. I guess the cooling period is over and it’s time to book spots on those Northwest passage cruise lines before all the polar bears drown.

September 25, 2009 8:37 am

Well, I took a look at the current stretch of silence in the Atlantic. It’s approaching a record for the last 30 years during the month of September.

September 25, 2009 8:41 am

Can I have that in proper POHM England please?
Prisoner of her majesty???

Jim Clarke
September 25, 2009 8:49 am

‘For example, Lund says “there is less than a one in 100,000 chance of seeing this many storms occur since 1965 if in truth changes are not taking place.”
Radar (05:26:42) is partially correct. This statement will be used by Romm and his ilk to promote their view, but Radar is wrong in believing that the statement supports that view.
The statement actually supports both views, or none at all. It is practically meaningless. With or without humanity, the Earth is in constant flux. With or without humanity ‘changes’ would have taken place over the last 44 years and the number of storms would have fluctuated. By definition, we would call these changes ‘natural’. It is through the recognition of natural changes that the increase in Atlantic Hurricane activity in 1995 was correctly predicted almost a decade earlier. Nothing in the CO2 theory supports the step change in hurricane activity that we have observed. Natural changes explain it very nicely, along with the general trend since 1965.
Lund’s statement by itself says nothing about AGW, but Romm and Radar will spin it the way they want to. I think Lund said it that way just so they could spin it. Most AGW studies, showing no hard evidence of a human influence, phrase there conclusions that way.

September 25, 2009 9:05 am

Is the historic record of total hurricanes gathered on the same basis as that of today?
Can a good estimate of historical numbers be made?
Answer: GIGO
Many scientific papers fail this simple sanity check – this is yet another one.
When will real Climate science start replacing this pseudo-science rubbish?

September 25, 2009 9:09 am

Here’s part of the abstract:
This paper studies changepoint detection in time-ordered sequences of categorical data. When the data are sampled from a multinomial distribution, the proposed test statistic is the maximum of correlated Pearson chi-square statistics. This test statistic is linked to cumulative sum statistics and its null hypothesis asymptotic distribution is derived in terms of the supremum of squared Brownian bridges. The methods are used to identify changes in the tropical cyclone record in the North Atlantic Basin over the period 1851-2008.
Here’s my translation:
Since nobody really has wind speed data of massive storms prior to 1920 and only crappy incomplete data until 1950 we used highly confusing mathematics to translate the well known increase in detection into more severe storms. Send checks to…
It is unbelievable that they want to pass this crap off. The true answer is — WE DON’T KNOW!
Lucy Skywalker has an interesting post at tAV.

September 25, 2009 9:53 am

Studies have shown that the hurricane frequency/intensity is on a cyclical basis (approximately 60 years). It is closely related to the AMO.

September 25, 2009 10:03 am

Did anyone see that NOAA is looking to change their hurricane strength rating system? I wonder what this will do to the hurricane frequency vs strength statistic?

September 25, 2009 10:17 am

This is junk science as there is no scientific way to make a comparison of hurricane frequency or intensity prior to satellites. It is sad when this type of analysis comes from a university when a bit of common sense would provide limits for selecting the appropriate data.

Adam from Kansas
September 25, 2009 10:49 am

Well let’s consider the fact for this year Unisys is showing an El Nino wannabe (that means a non-nino) in the Pacific and the fact it’s been reported cold fronts are making it all the way down to Florida. It seems like hurricanes are having a hard time forming this year considering this even without a good El Nino to induce wind shear.
Also regarding Jaxa, one half day does not even make a short term trend and it takes time for the Sun to affect the Earth’s climate.
Also, I do note the AO index is strongly positive right now, looking at NOAA’s graphic of the polar vortex strength it seems like positive readings are often associated with a strong vortex. Intellicast’s forecast maps seem to predict below freezing temps. in more places in North America currently than in Siberia, cold air still possible in parts of South America and cool air masses washing over parts of Australia again. Also in North America they’re forecasting colder air across large sections of Canada with perhaps some of it spilling into the U.S.
For our area we get a warm up to the low 80’s in 2 days followed by a possible streak of temps. in the 60’s to start October with.

George E. Smith
September 25, 2009 11:31 am

“”” “The study represents one of the first rigorous statistical assessments of the issue with uncertainty margins calculated in. For example, Lund says “there is less than a one in 100,000 chance of seeing this many storms occur since 1965 if in truth changes are not taking place.” “””
First of all; who says changes aren’t taking place ? Natural variability would be one example of changes taking place.
But that last sentence is a humdinger. Does that mean that if 100,000 research groups studied the number of storms occurring since 1965, that only one of the studies would show a (significant) difference in storm number from this study.
How do you apply statistics to an event that has only happened once in all of time; namely the sequence of storms that has occurred (or is believed to have occurred) since 1965.
Assuming that these mathematicians know how to count storms, one would presume that they got the number since 1965 correct; are they suggesting there is one chance in 100,000 that they counted them incorrectly.
Now I’m perfectly happy to let mathematicians perform statistical AlGorythms on any arbitrary set of numbers they want to concoct; such as the number of animals bigger than a flea per hectare of the earth’s surface.
I start to cringe when they start assigning some meaning to their results.

Robert Lund
September 25, 2009 11:37 am

It is amusing to read the above comments. Edcon, I suggest you read before speaking. You made by bulletin board.
Point of facts are that as statisticians, we are not invested in the outcome. We don’t care what the end conclusions are….we just analyze the record as it is. And we know the laws of probability very well (so we cannot cheat).
In this case, the counts are clearly going up recently, but we see no changes in the strengths of the storms. Blame it on whatever you want, or spin it, but that is what we find.
If you will read the paper, you will find that the crux is about how to develop methods to rigorously assess the issue, not whether global warming is responsible for any changes that we see. It could very well be that the recent increase in counts is due to increases in very small storms that “barely make it into the record”, i.e., observational biases.

September 25, 2009 11:40 am

I have asked this question before, and gotten no reply, so I will ask again.
Through what possible mechanism can an el niño event raise the mean global temperature?

September 25, 2009 11:41 am

Thank you for coming by Dr. Lund.
People, please treat Dr. Lund with respect and courtesy.

September 25, 2009 12:09 pm

enduser (11:40:38) :
“Through what possible mechanism can an el niño event raise the mean global temperature?”
At the beginning, the tropical trade winds blowing out of the east near the equator stop, so there is no wind friction to cause upwelling of cold water off the coast of South America and to blow the warm surface water westward. So the surface water in the eastern tropical Pacific stagnates and warms which shows up as an increase in global temperature. Strong trade winds have the opposite effect, a “La Nina”.

September 25, 2009 12:11 pm

“Patrick Davis (04:36:45) :
Homo praesumitur bonus donec probetur malus?
Can I have that in proper POHM England please?”

My taylor is rich.

September 25, 2009 12:16 pm

re: Jim Clarke
I’m no warmist. My point was to question if wuwt (and those of us who frequent wuwt) should be trumpeting one conclusion of this paper, (no increase in intensity) and rejecting another (increased frequency). Seemed sort of like cherry picking to me.
Dr. Lund,
Your quote from the article “we do find that the number of storms has recently increased.”
Is completely different from,
“it could very well be the recent increase in counts is due to increases in very small storms that barely make it into the record”
Having read your reasoned comment above, I now take the original quote to have meant “we do find that the number of [observed] storms has recently increased.”
But the original quote will be used by the loudest doomsayers of AGW.

September 25, 2009 12:20 pm

“”It could very well be that the recent increase in counts is due to increases in very small storms that “barely make it into the record”, i.e., observational biases.””
There you go. Back in the sailing ship days they wouldn’t have noticed these.

Tim Clark
September 25, 2009 12:36 pm

Charles aka “board wielding” moderator:
Is WUWT going to hit twenty million hits today?
Reply: According to the sitemeter bug yes, but if you click on it and view stats, then no. ~ charles the board wielder of grumdorr
REPLY: the 20 million counter is from WordPress and is internal, which yields the greatest count accuracy. The sitemeter bug is external, with less accuracy, and I also started it a few months AFTER I started the WordPress blog, so it won’t line up, ever. I use it to see some details I can’t get from WordPress. – Anthony

Bob Koss
September 25, 2009 12:39 pm

Accurate statistical treatment done on inaccurate data results in an erroneous representation of reality. Due to historically poor observational ability you can’t use the early part of the record in a storm frequency count and say the increase has any validity in the real world. Satellites have changed the game with respect to all of the older non-landfall frequency counts.
Observations are recorded every six hours. The Atlantic database has 31 storms with 1 observation and 3 others with 4 observations. All those storms were recorded prior to 1871. Two thirds of those were found because they hit land or were sighted within 200 miles of land. 14 of those were full blown hurricanes when discovered. Gimme a break! There were two storms in 1990 each of which lasted 2 weeks that never came within 300 miles of land. Can there be much doubt that many storms in the early record weren’t recorded at all?
It was concluded the frequency of landfall storms hasn’t changed. Not very surprising since that is where humans predominately spend their time and likely have an accurate storm count. The vastness of the ocean has hidden a multitude of older data.

September 25, 2009 12:43 pm

radar (12:16:49) : “My point was to question if wuwt (and those of us who frequent wuwt) should be trumpeting one conclusion of this paper, (no increase in intensity) and rejecting another (increased frequency). Seemed sort of like cherry picking to me.”
Here’s the thing. “Rejecting” has a specific scientific meaning as in “the hypothesis is rejected”. “Trumpeting” does not. However, one has to be ready to go where the evidence takes one self. The evidence that the paper cites for increasing frequency fails tests of “robustness” (like: )
And therefore is rightly rejected as a hypothesis. Now, I want to see the paper before buying their conclusion about storm intensity, however since I do not have a reason to yet, I cannot reject there hypothesis. And it sounds like they probably didn’t screw up in some major way.

September 25, 2009 1:11 pm

The key words are “have been observed”, and for that matter, recorded except for a notation in some ship’s log. Most hurricanes don’t make landfall. In the 19th Century the number of ocean shipping routes increased, along with more shipping, along with wireless radio.
First in the 20th Century came the airplane, and many which would not have been noted at all were then recorded. As over ocean air routes and numbers of these flights increased, more were noted and recorded than otherwise would be. Then came satellites, and all of them are now observed, no matter how small or insignificant to humans they might be.
Hmmm, 2 total this hurricane season so far, I do thinik. I don’t pay as much attention since I moved to Phoenix, AZ from Jacksonville, FL 5 years ago.

P Wilson
September 25, 2009 1:19 pm

There are one or two disclaimers:
“While the study did conclude that more storms are being documented, researchers found no evidence of recent increases in U.S. landfall strike probability of the strongest of hurricanes. ”
“The increasing frequency of storms in the last 50 years is to be expected, due to better reporting and improved technology like satellites, Hurricane Hunter planes, and Doppler Radar.”
So please Mr Lund, is it possible that there isn’t a necessary increase in number of storms if current technology allows you to capture more of these events?

John G
September 25, 2009 1:25 pm

An increase in the number of tropical storms and hurricanes but not an increase in the strength of those storms? I was looking for words to the effect that the proportion of the various categories of storms remained constant but it didn’t say that. it did say the number of big storms making landfall hadn’t increased, which leads me to think they’re counting a whole lot more smaller storms. That makes me think they’re just getting more observant but otherwise things haven’t changed much.

Kevin Kilty
September 25, 2009 1:52 pm

enduser (11:40:38) :
I have asked this question before, and gotten no reply, so I will ask again.
Through what possible mechanism can an el niño event raise the mean global temperature?

Let me have a stab at this. For a variable length of time an excess of solar energy becomes stored in the Pacific Warm Pool. The storage is largely at depth, however, so that this energy cannot reach the surface and be transported into the air. During an El Nino this water becomes spread over a large ocean area in the Pacific and transport to the atmosphere is now quite rapid. Temperatures over a large fraction of the globe increase. There is increased water vapor transport also, and perhaps even an enhanced radition effect from this water vapor.
At this point the global mean temperature is above an equilibrium value (supposing that the global mean temperature is a meaningful measure of equilibrium in the first place.) One might expect a return to equilibrium rapidly. However, there are a number of feedback mechanisms that can prevent a rapid return to equilibrium; most specifically a feedback involving cloud cover, or even others involving albedo other than clouds. I doubt that anyone can say with confidence what is the actual time span required for return to equilibrium, but decades needn’t be beyond the question. Now organize a number of unusually strong el ninos in succession and one might even get an impression of temperature trends characterized by the term “climate change.”

George E. Smith
September 25, 2009 2:12 pm

Well I’ll take professor Lund’s assertion at face value; that they just analysed the record; fair enough. If we want to investigate the meaning of this, we probably have to look at the raw record; which if I understand correctly is summarised (numbers) in his graph of numbers of cyclones.
I do have one criticism of the method of presenting the results.
Presumably each and every storm (cyclone) is a single unrelated event, with no known linking mechanism between storms. They presumably happen as random events; admittedly in a framework of seasonally varying weather patterns; and by happenstance, you count a certain number that meet some criterion in an arbitrary 12 month time interval.
Just as the individual cyclones would seem to have no cause and effect linkage to each other; so too, one would expect the annual counts to be unrelated as well.
So to me it makes more sense to simply plot these annual totals as a scatter diagram of dots.
Linking the dots as if the graph represents some continuous function makes no sense to me. If somebody can fit this function to some mathematical equation having fewer parameters than the number of plotted dots, then I would change my mind; but as it is, the zig zag line shows no ability to predict what the next point to be plotted should be; or even the direction of the next move; but a casual glance might suggest that if one adopted the rule; “Whatever it did for the most recent move, it will do the opposite for the next move.” The data doesn’t adhere rigorously to such a rule, so it can’t be the correct rule, which is why I say the direction of the next move is not predicatble, nor is the extent of that move.
I hate to keep whipping a dead horse; but dare I suggest that the Nyquist theorem does not justify the reconstructed signal evidenced by this zig zag graph; so it should be left as a dot scatter plot.

robert Lund
September 25, 2009 2:43 pm

(Fake name. Snipped entirely. A lot of your time was wasted writing that comment, eh David? -mod.)

Jim Clarke
September 25, 2009 3:29 pm

Dear Mr. Lund,
I see that you are a professor of mathematics, so when you say: “And yes, we do find a change (increase) in counts circa 1995 that has no easy explanation.”, I can only assume that you are not aware of the climatological work that has been done on this issue.
While the mechanism for many natural climate cycles is not well understood, there is no question that these cycles exist. Often, they exist in concert with other cycles, each one varying at their own rate, and producing results that are never exactly the same each time they manifest. Yet we can and do recognize these cycles, the most prominent one being the ENSO events. Evidence for multi-decadal events is also quite robust. It was through such recognition that the increase in Atlantic Hurricane activity in the mid 1990s was predicted long in advance.
Your broad statement that there has been an increase in the number of storms since 1965, while true, seems designed to support an AGW cause. The more accurate statement, which you made in the comments above, supports the idea that natural variability is primarily responsible for the observational data, as AGW can not explain the lack of a trend from 1965 to 1995, with a sudden step change thereafter.
With no evidence of a human influence on Atlantic Hurricanes, you have made a statement that implies that there might be a human influence and most certainly will be used that way. I find it extremely hard to believe that the statement was made with no intent to support the AGW argument. Your comment above was much more descriptive (although still scientifically incomplete) than the ‘general increase’ statement being fed to the press.

David Segesta
September 25, 2009 4:31 pm

This story says there are more hurricanes. But this one below says there are fewer.
Who to believe?
It seems there isn’t even consensus on basic facts.

George E. Smith
September 25, 2009 5:08 pm

To amplify on my point about the method of presenting the data; my understanding of Professor Lund’s graph is that there is a single point plotted for each calendar year; or perhaps for some other 12 month period.
By connecting the dots; one is led to believe that intermediate data can be interpolated between the plotted point.
Now I can see in principle how one could take a running 12 month total (of maybe monthly/weekly/daily) cyclone counts, which could then be plotted as a continuous function with actual computed data between the annual points; and presumably such data could be generated if in fact the time of occurrence of each and every cyclone has been captured.
If in fact such a running 12 month total were generated, one would expect to see the frequency spectrum of the plot more clearly, and I dare say such a plot would point out the fallacy of connecting the annual dots as in the presented graph.
Other than that, I have no quarrel with the study; it would be nice if someone with some specific climate or weather data on each of these storms could correlate such data with just Prof Lund’s cyclone counts.
But it is interesting to point out that “global temperature” anomaly data such as GISStemp; that purports to have a long historical record (well 150 years) also suffers from the fact that while the data has been gathered, the construction workers have been continuously working on building the laboratory; and the way it is today, is nothing like the quanset hut shack that existed at the start of the study.
Climate scientists tend to act as if they have been monitoring a static system for long periods of time; whereas in fact the system has been under constant construction since the first such measurments were taken.
And as Anthony’s survey of the GISStemp data sites has shown; some parts of the system have decayed, rather than been enhanced.
There’s not much Professor Lund can do about the fact that his system was also a work in progress as far as the constancy of data gathering methodology.
I’m sure that just pointing out that the data source itself has been under constant modifications; is itself a valuable piece of information, that should tempera the desire to read too much into the results (climatically)

Richard M
September 25, 2009 7:04 pm

As far as I can tell this report is only good news for the anti-AGW contingent. No increase in stronger storms is the opposite of what AGW proponents have been claiming. As indicated in the article, there’s an obvious explanation for the increase in storms … observation.
Looks pretty cut and dried to me.

John F. Hultquist
September 25, 2009 10:20 pm

enduser (11:40:38) :
Kevin Kilty (13:52:03) :
Suggestions for reading about el niño events raising the mean global temperature:

Ulric Lyons
September 26, 2009 4:04 am

The US landfall record gives 76 events (category 1 or above) for the past 50yrs, and 97 events for the previous 50yrs.
With category 3 and above, there were 26 events in the last 50yrs, and 39 events in the previous 50yrs.
Ships can sail away from storms, the coast cannot be moved.

Mike McMillan
September 26, 2009 6:07 am

The chart shows a rising slope starting in the 1970’s, consistent with the increase in satellites. This seems analogous to the number of tornadoes rising along with the increased availability of weather radar. The lower ACE index is consistent with the lower number of severe tornadoes despite the higher number of reported tornadoes.
The only count that would eliminate this bias is the number of hurricanes making landfall.

September 26, 2009 6:32 am

@Patrick Davis (04:36:45) :
“King of Cool (03:10:49) :
Homo praesumitur bonus donec probetur malus?”
Can I have that in proper POHM England please?
Since you asked nicely, ” Man is presumed innocent until proven guilty.”
I presume King of Cool’s point to be (and I agree) that, recognizing the myriad natural factors in climate variability, Man should be presumed innocent of any contribution until proven guilty. It seems that the opposite POV is in operation in most of climate science these days. Instead of searching for the truth, they seem to assume Man is guilty and are trying to find as many ways possible to prove it.
Thanks for stopping by. The above comment is not directed at you, as I have not yet had a chance to read your study. But I would caution that very precise wording in your conclusions is necessary or people from both sides of the AGW debate will take a study’s results to places you never dreamed of them going.

September 26, 2009 6:32 am

To those that answered my El Niño question: Thanks.

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