Update: Dr. Roger Pielke Jr. says via email “the fake photo is perfectly appropriate” and adds this update to his report on Grinstead from last year:
Today Grinsted et al. have another paper out in PNAS in which they follow up the one discussed below. They make the fantabulous prediction of a Katrina every other year. They say in the new paper:
[W]e have previously demonstrated that the most extreme surge index events can predominantly be attributed to large landfalling hurricanes, and that they are linked to hurricane damage (20). We therefore interpret the surge index as primarily a measure of hurricane surge threat, although we note that other types of extreme weather also generate surges such as hybrid storms and severe winter storms. . .
As I showed in this post, which Grinsted commented on, the surge record does not accurately reflect hurricane incidence or damage. Another poor showing for PNAS in climate science.
– Anthony
Guest Post by Willis Eschenbach
Anthony has commented on the recent paper by Grinsted et al. in his post called “Model predicts more storm surge, but they use what appears to be a fake photo in the press release“. The original study Abstract is here, but the paper has not yet been published. Fortunately, the supplementary material with their summary data is online here. This is the relevant quote from their Abstract (emphasis mine).
We find that warm years in general were more active in all cyclone size ranges than cold years. The largest cyclones are most affected by warmer conditions and we detect a statistically significant trend in the frequency of large surge events (roughly corresponding to tropical storm size) since 1923. In particular, we estimate that Katrina-magnitude events have been twice as frequent in warm years compared with cold years (P < 0.02).
Their claim from the abstract is that historically, warmer years have larger storm surges from cyclones … which seemed doubtful to me. So I got their “Surge Index” data from their Supplementary Information, and took a look. Figure 1 shows the results. I have plotted the size of the surge against the temperature anomaly for the month in which the surge occurred.
Figure 1. Surges plotted against the HadCRUT3 temperature anomaly for that month. PHOTO: Wolf Rock Lighthouse
Well … that sure doesn’t show what they claimed. There’s absolutely no trend in that at all. In particular, “Katrina sized events” (storm surge >= 113) are more common and larger in the colder months, not the warmer months. So having failed there, let me try something else …
They talk about warm and cold years, not warm and cold months. I’ll give that one a try. Figure 2 shows the previous Surge Index results compared to the temperature for that year, rather than for the month … or it will as soon as I go calculate, create, and shoot Figure 2 … OK, here it is.
Figure 2. Surges plotted against the HadCRUT3 temperature anomaly for that year.
That didn’t help in the slightest. Again, no trend in storm surge index with respect to temperature. And again, “Katrina sized” events with a storm surge 113 or greater are more common in the colder years.
So I fear that I can’t replicate their results. They may be using some very sophisticated analysis … but in my experience, if a trend were actually present, it would show up in one of the two charts above.
What am I missing?
Regards to everyone,
w.
DATA: Spreadsheet with the values is here.
[UPDATE] A reader points out that the paper is now available here.
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Hey Willis, do a plot of the difference between the arctic temperature anomoly and equatorial temperature anomoly and the storm surge. See if anything interesting happens then.
Willis,
What you are missing is that there is no additional funding if there is no CAGW-related signal.
The Weather Channel is already trumpeting this study. Just saw them using it tonight.
Willis, thats not climate science – where’s the hockey stick? 😉
Paper available via this link.
http://www.glaciology.net/Home/PDFs/Announcements/ahomogenousrecordofatlantichurricanesurgethreatsince1923
A strong surge in overconfidence by Alarmistas about the supposed meltdown in the Arctic.
Arctic ice recovery continues. Yet again the total ice extent is thundering towards normal. The extent is normal over much of the Arctic; Bering Sea well above normal:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.2.html
There is a trend…..(statistically completely irrelevant)
-0.29*x (monthly) and -0.08*x (yearly) which means the warmer it is, the lower the surge index is!
How can they claim the opposite??
Yesterday, I could not arrive at any conclusions.
You are not missing anything, Willis. They are. Looks to me like they don’t even make a show of checking actual facts – they just make it up.
[snip . . OT . . mod]
You are not using Mannian mathematics, or adjusting the data using a Marcott time series. Once you do that, everything will become clear.
As Robert Wykoff suggests, Dr. Lindzen (MIT climatologist; a real one…) postulates that it’s the magnitude of the latitudinal temperature differential that tends to create big-storm years.
Accordingly, in a warming Earth, the latitudinal temperature differential would tend to be less which would lessen storm severity.
@Willis,
You are missing the grant money that told you to find that storms were higher in hot years…
😉
So here, let me help you. First, that one spot way up high in a cold year, toss it as a suspect data point / data anomaly. Now you have 3 and 3 above the 100 line. As that’s equal, we need to ‘fix it’. Set your ‘cut off’ for ‘warm’ at 0.2+, everything below that is ‘cold’. Seeing that there are a whole lot more data points total on the cold side, we now have our method. Make it a “percentage of total storms”. Those three high rank in the cold times are a smaller percentage of all storms then. As there are few storms during warm times, those three become a larger percentage. Presto! More major storms in hot time! Easy peasy.
Can I have my grant now?
I still can’t come up with any conclusions.
Sample intensity.
Sample frequency.
Perhaps the solution is this: Grinsted et Al considered temperature anomalies of -0.4 to +0.4 degrees C to be ‘normal’ and only considered data points outside those parameters. There are no data points below -0.4 degrees C and a few above +0.4 degrees C.
I guess that is a statistically significant trend and makes sense if you are a climate scientist.
Willis
I have now looked at tens of thousands of contemporary and later weather records dating back to 1000 AD. Some of these were contained in my article ‘the long slow thaw’ which extended CET to 1538 from its instrumental start in 1660.
http://judithcurry.com/2011/12/01/the-long-slow-thaw/
I am currently concentrating on researching the preriod 1250 to 1550 in order to try to pinpoint the transition from the MWP to the LIA.
It is quite obvious from reading the weather observations that the majority of extreme weather events- including storms- take place during the cold-not the warm-periods. This is hardly surprising as there exists a greater potential energy differential betweeen cold winters and hot summrers- which were common during the LIA- than there are in the more benign and equitable climate we enjoy today.
tonyb
If they are lying on our tax dollars then haul the responsible gov agency in front of Congress and demand they either back up their claim or forfeit anymore funding for 10 years.
Good “back of the envelope” analysis, Willis. The correlation between temporary SST “anomalies” and tropical storm intensity is well established; alarmists want to read an anthropogenic signal into the picture — that is where it gets difficult.
I find this 2008 article from Thomas Knutson of the NOAA’s Geophysical Fluid Dynamics Lab (with updates from January 2013), while paying the required lip service to the IPCC projections of a stormier world over the next century under “greenhouse gas induced warming” (see final paragraph), to be a good summary (and far removed from the fear-mongering of Kerry Emmanuel and others).
http://www.gfdl.noaa.gov/global-warming-and-hurricanes
The following quote is the “money” one: “…there is a small nominally positive upward trend in tropical storm occurrence from 1878-2006. But statistical tests reveal that this trend is so small, relative to the variability in the series, that it is not significantly distinguishable from zero.”
Alarmists want so badly to see evidence of continuously worsening weather, they find it hard to contain their Schadenfreude when a big storm like Katrina or Sandy hits. Thereafter, the tabloidazition runs amok and exploitation of damage and destruction has a field day — damn the science. The general public believes all the fear-mongering – while sober analyses are buried, empowering politicians and administrators to incorporate yet more draconian measures to combat “human-caused” CO2. Never mind that this is ONLY being done in the W. World.
Kurt in Switzerland
I’m still trying to arrive at some kind of conclusion about the future of warming. 🙂
It may be that the frequency and strength of hurricanes at least partially relates to the temperature differential between the tropics and the higher latitudes. If the higher latitudes warm faster than the tropics during global warming (which is what is occuring), then the number and frequency of hurricanes might actually decrease with global warming, since the temperature differential has declined.
The same might also hold for tornadoes, which are formed when very cold air mixes with very warm air (best developed in the southen USA); if the cold air is less cold due to global warming, and the overall temperature differential smaller due to differential global warming, then tornadoes might become less frequent and less severe, the exact opposite of what the alarmists predict.
You can see this sort of principle in the ocean called the ‘Pacific’-it was named the Pacific (i.e. peaceful) by Magellan because it struck him as being less violent and prone to storms than the Atlantic, despite the fact that it is much bigger. This may be due to the fact there is less land about the Pacific basin, and therefore the temperature across a greater area is more evenly spread, which might mean less storminess overall.
Also, 1998 was noted in the southwestern Pacific anyway as being unusally calm in terms of swell and general storminess (I know because I am a surfer, and everybody noted then that there was virtually no swell in Eastern Australia that summer), depsite it being a very warm summer. Higher temperatures in the Pacific had a pacifying effect on the southwestern end anyway, possibly because temperature differentials were generally lower.
Yes, E M Smith has a suitable methodology. I myself would have discarded the 7 high points centered around -0.2, because they are obviously spurious. Now a simple trend line will show a spread from below SI 50 to about SI 100. That gives you the claimed doubling.
I would be happy to ‘peer review’ E M Smith’s paper if he will ‘peer review’ mine. We can then have two quite distinct reviewed mathematical analyses ready for ‘publication’ via the press and inclusion in AR5.
Ha! Deniers! You’re in the wrong business! Here are E M Smith and I saving the world, and being paid handsomely for it, while you are still looking for a real signal… /sarc
Well done Willis. When the sophisticated modelling is contradicted by simple graphs or pivot tables good science should try to reconcile those anomalies. Instead we have claims that the scientists know what they are doing, but the truth is beyond the understanding of lesser mortals.
An example I found was the notorious LOG12 paper.
http://manicbeancounter.com/2012/10/04/the-role-of-pivot-tables-in-understanding-lewandowsky-oberauer-gignac-2012/
Given that Katrina was a Cat3 middle of the road average storm then these would be the most common. It is the Cat5’s that would be a possible indicator.
So this paper is a ”storm in a teacup” load of alarmist rhetoric.
Ignore, file under spam.
I see no trend in the graphs, and I’m a six sigma green belt process engineer. I looks at graphs like that every day…
What should I make of the following for the NH bearing in mind storms like temperature differentials.