Note:John Droz asked me for help with research yesterday, and while I have no time at the moment, I did suggest he contact Bob Tisdale, and this is the result. In an effort to get him some help, I present this on WUWT – Anthony
Guest Post by John Droz, Jr.
Friends:
I am asking for help from oceanographers and/or others who have experience with sea level measurements.
I am a physicist (energy expert) who has been involved with several environmental issues over the last thirty years.
I am a traditional scientist in that I am a strong advocate of subjecting hypothesis for solutions to our environmental issues to the Scientific Method. In other words, I would expect that proposed solutions have a comprehensive, independent, transparent and empirical based assessment. (Unfortunately, this now seems to be the minority view among scientists.)
I have written extensively on energy issues, and have given free presentations in some ten states. This is online at EnergyPresentation.Info. There are also several slides about AGW.
Anyway, the case at hand is that I was recently asked by my local representatives for some scientific assistance.
The brief story is that North Carolina is attempting to be the first state in the nation to impose rather comprehensive and consequential (i.e. expensive) rules and regulations on its coastal communities. This is based on projected substantially increased sea levels, due to the assumed effects of AGW.
But it’s worse than that. The basis for these changes is a 2010 NC Sea Level Assessment Report (http://dcm2.enr.state.nc.us/slr/NC%20Sea-Level%20Rise%20Assessment%20Report%202010%20-%20CRC%20Science%20Panel.pdf).
I have been told that the US federal government funded this study. The stated intention was that they would like that this study be used by the rest of the coastal states (plus the federal government) as a basis for new rules and regulations. If this came about as planned, there would clearly be worldwide implications to this simple report.
As such, it is my view, that it is imperative to get it right.
In my reading of the report, the key assumptions are that:
1 – the IPCC sea level rise projections (15± inches by 2100) are the minimum expected, and
2 – that Rahmstorf (rahmstorf_science_2007, is a credible source to use as a high end (55± inches by 2100).
To give the appearance of being reasonable, the report authors (13 esteemed scientists) selected a value near the middle of these numbers: 39± inches by 2100.
Figure 2 (page 11 of the NC sea level report) and the accompanying text in the report shows and explains this.
This is not my area of expertise, so I can not make a technical critique of Rahmstorf’s work, or the referenced Church & White (2006) report. If anyone can provide some scientific evidence, pro or con, regarding these documents, it would be greatly appreciated.
Again, what happens about this in NC will likely be a precursor to other coastal states (and countries), so this is an international big deal.
Feel free to email me directly at “aaprjohn [ at ] northnet dot org”.
THANK YOU!
john droz, jr.
physicist & environmental advocate
Morehead City, NC
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I want to thank all who graciousy took their time to make comments here.
I will seriously consider each one. Of those that I have had the time to investigate so far, many have proven to be insightful. I have contacted most of the experts recommended, and they have been helpful.
I will hopefully finish a report on this sometime next week, so additional comments will still be considered.
Apologies to initial readers, that (due to my error) the wrong “Figure 2” was shown in the article. It is correct now.
If anyone wants a copy of my report, please email me your name and email. My email is “aaprjohn” at “northnet.org”.
The analysis of sea-level variations is very, very tricky due to the varying datum levels in the historical tide gauge records and the highly erratic nature of the changes. Sattelite records are simply too short to establish a secular trend, which starts to emerge stably only in records longer than half century. If you ask the few oceanographers who are truly expert on the subject, they’ll give you a long-term expectation of 2-3mm/yr. Of course, some know-all nonoceanographers will give a far greater and more certain answer.
Contact/Google Dr. Nils-Axel Mörner
steven mosher says:
February 25, 2011 at 12:01 am
If you ask me to use the best available science to predict sea level rise, I’ll use the historical trend. Since there was allegedly all of this CO2 caused warming in the last century, and since there has been no corresponding increase in sea level rise in either the tide gauge or satellite records (indeed, there is a recent decrease in the satellite records), I fail to see why you would use a Tinkertoy model rather than the measurable lessons of history.
I fear you have not completely grasped the limitations of using a trivially simple linear model in a thermostatically regulated chaotic system if you really think that the limitations of GCMs are so minor. I can replicate the GISS model output with a single line, single-variable equation. Are you seriously claiming that simple equation even approximately models the planetary climate, much less models it well enough to inform our judgements?
If you don’t think that “limitation” precludes any serious use of such models, I don’t know what to say. I use computer models, I write them, I love them, but the GCMs are junk.
Having said that, I’d expect around a foot of raise over the next century. Triple that for a safety factor for structures that are likely to be around that long, so about a metre as a design guideline.
Also, with intelligent planning, you can often respond incrementally to increasing sea level. Walls can be raised, piers can be jacked up, wharves can be filled and resurfaced. So the actual guidelines need to differ for different kinds of structures.
The real uncertainty, of course, is not in the sea level. It is in the storm surge plus tide plus runoff. The storm surge is the huge area of water under the center of a hurricane that is driven onshore with a hurricane. These can reach as much as eight metres or so above the normal sea level. Couple that with a high tide and huge rainfall runoff coming from the land side and a wind driving the water even further onshore … I don’t think the difference between an 18″ advisory height or a 36″ advisory height will matter a tinker’s dam at that point.
In any case, after a century of warming, we show absolutely no sign of the widely heralded CO2 induced increase in sea level rise. None whatsoever. On the other hand, a quarter century ago Hansen said his model showed parts of Manhattan would be underwater.
Now, in the face of that, I’m sorry, Mosh, but I’m not going to believe the models. I’m going to believe the historical data on how the sea is actually behaving, over Hansen’s synthetic ocean. You’re free to follow Jim Hansen down the rabbit hole of models if you wish, where they believe six impossible things before breakfast … but you can’t convince me that’s the “best available science”.
w.
See also Putting the Brakes on Acceleration.
Anthony,
Has my 48-hour timeout expired yet?
I’d like to make a comment here, as I have some expertise in this area (USACE ERDC CHL, and first worked at the FRF (Duck, NC) for Mr. William Birkemeier, at the start of my Coastal Engineering career.
Thanks.
REPLY: Comment away, be civil. – Anthony
OK then, well first off I’m in almost total disagreement with most of what Willis just stated above.
The storm surge is not under the center of the hurricane, that is just the low pressure bulge, which is at most ~3 feet. The storm surge is wind and wave driven at the shoreline. I almost always occurs in the NE quadrant of the hurricane’s path in the NH and the SW quadrant in the SH, given their CCW and CW rotations, respectedly.
Most of the Atlantic and Gulf coasts coastal areas are in areas of low land relief, think 1:1000 or 1:10000 slopes. The vast majority of our barrier island system is below +10′ MHHW.
When I worked at the Outer Banks (FRF) we had a tropical storm with about a 3-4 foot storm surge, the beach road was inundated with 2-3 feet of standing water, and we went around in chest waders checking out buildings and the shoreline, kind of fun actually.
Storm surge, at the coastline proper, is just one rather small factor. Inland inundation is the ultimate killer.
Thus, adding just one additional foot of sea level, can lead to additional miles of inland inundation.
The USACE has a state-of-the-art GCM (general circulation model) called ADCIRC which is used to perdict storm surge and inland inundation from hurricanes and extra-tropical storms. I can assure you that ADCIRC, as a GCM, is definitely not junk.
The USACE current guidance on sea level rise is the IPCC AR4 WG1 estimates, which IMHO are rather conservative (low) as we speak today, given many subsequent research papers, and what we know is happening in the Arctic (and the potential implications this has for the western side of the Greenland ice sheet).
The USACE can be rather slow in updating their guidance, and they are at odds many atime with respect to beach nourishment projects due almost entirely to local political considerations.
Now in offshore engineering designs, the usual factor of safety (FS) is ~three times the actual calculated, or expected theoretical forcings. In soils engineering, FS’s are typically 6-18, and in structural engineering, FS’s are typically 1.5-2.0.
Thus, even if we take a linear extrapolation of current sea level rise, at ~3mm/yr, we end up with the magical one foot number by the end of the 21th century.
Thus a prudent coastal engineer “should” be using, for design guidance, a FS of ~3 attached to the minimum expectation of sea level rise (the one foot linear extrapolation), leading to what I believe the NC people have done with respect to their report recommendation of 39 inches (one meter). This is where I agree with Willis.
What this will mean is that coastal structures (new builds only) will need to be built (almost always on stilts) 39 inches higher than they are now currently built. If you go to the Outer Banks, even now, historical buildings built originally at ground level, are still there and still being used and lived in. Old existing buildings get grandfathered, in other words.
NC has historically been very anti-shore in terms of coastal structures and beach nourishment projects.
Also note that linear extrapolations of ~90+ years is a very bad idea IMHO.
Sea level rise is, IMHO, very much a laging indicator of potental global warming effects. It will be the last thing we see, for sure, when/if ##it hits the proverbial fan.
Finally, as an aside, if you don’t code in Fortran, than you are neither a serious research scientist or a serious research engineer IMHO, if you don’t code the models, if you’ve never used the models firsthand, that of which you cast down, you simply don’t have the slightest clue what all you are talking about in the first place.
Models are a tool, they serve a purpose, you might not like what the models say, but they are the best tools we have at any given point in time. Heck, here at CHL, we rarely use a physical model today, which is a dramatic change from just 10 years ago, even.
EFS_Junior says:
“The storm surge is wind and wave driven at the shoreline.”
Well, that’s part of the surge. Wiki defines a storm surge this way:
So the surge is the combined effect of low pressure [the eye of the cyclone], wind/wave action, tides and flooding. How does that make Willis wrong? Junior also says:
“Sea level rise is, IMHO, very much a laging (sic) indicator of potental (sic) global warming effects.”
Wait a minute. For years and years we’ve been told by the alarmist crowd that sea level rise proved that CAGW was already happening. Now it’s a lagging indicator?? Talk about moving the goal posts! Is that lag sort of like the rise in CO2 levels 800 years after a rise in temperature is a “lagging” indicator of temperature?
Junior says of Willis, “…you simply don’t have the slightest clue what all you are talking about in the first place.” I think the rational folks here would strongly disagree.
Smokey says:
February 27, 2011 at 6:29 pm
EFS_Junior says:
“The storm surge is wind and wave driven at the shoreline.”
Well, that’s part of the surge. Wiki defines a storm surge this way:
It is this combined effect of low pressure and persistent wind over a shallow water body which is the most common cause of storm surge flooding problems. The term “storm surge” in casual (non-scientific) use is storm tide; that is, it refers to the rise of water associated with the storm, plus tide, wave run-up, and freshwater flooding. [my emphasis]
So the surge is the combined effect of low pressure [the eye of the cyclone], wind/wave action, tides and flooding. How does that make Willis wrong? Junior also says:
“Sea level rise is, IMHO, very much a laging (sic) indicator of potental (sic) global warming effects.”
Wait a minute. For years and years we’ve been told by the alarmist crowd that sea level rise proved that CAGW was already happening. Now it’s a lagging indicator?? Talk about moving the goal posts! Is that lag sort of like the rise in CO2 levels 800 years after a rise in temperature is a “lagging” indicator of temperature?
Junior says of Willis, “…you simply don’t have the slightest clue what all you are talking about in the first place.” I think the rational folks here would strongly disagree.
_____________________________________________________________
So now you believe Wikipedia? 🙁
Storm surge is not due to the eye of the storm, as it were. Maximum storm surge, never has, and never will, occur in the eye of the storm, because, THERE’S NO WIND THERE!
Pressure drops significantly away from the eye of the storm simply due to the Bernoulli Principle, the pressure term is replaced by the velocity SQUARED term.
Simple enough concept for even you to understand, I hope.
For example, take Rita or Katrina, get their storm tracks, then get the storm surge data from both storms.
Guess what?
Maximum storm surges occures significantly far (tens of miles) from the accociated storm tracks, in there respective NE quadrants.
Heck, I live in Vicksburg, MS (USACE ERDC CHL also known as Waterways Experiment Station).
I’ve seen all the data from hundreds of storms, always the same, NE quadrant, never in the eye of the storm, it’s all just a matter of degree.
So that dispenses with your rather linited, or should I say, total lack of knowledge on said subject matter.
I won’t even bother with the rest of your nonsense.
First, EFS_Junior, despite its tone let me thank you for the science content of your post.
EFS_Junior says:
February 27, 2011 at 5:56 pm
Meaningless. Quote exactly what I said and tell me why you object to it. It’s also curious because generally you go on to agree with me.
My friend, I have lived through cyclones. I went through the tail end of one at sea on a 50′ sailboat. I watched the storm surge of another drive the ocean clear over the outer reef of Suva Harbor and into the bay. As an ardent lover of the weather, I had to see it firsthand, so I went outside on the high point of land where I lived. I was driven back in immediately, the rain drove bullets into my eyes and when I faced the wind and opened my mouth it pumped my lungs full of air. I went back inside defeated, but I had to see it. I put on my diving mask and snorkel and went back out. I could stand it, although to stand it I had to lean at about fifty degrees. So although my description might not be up to your standards, your claim that I don’t understand a cyclonic storm surge is a joke. I’m a weather guy. I watched the cyclone as it rolled in, I studied its path, guessed at where the “dangerous quadrant” would strike.
Agreed, very clear.
I can assure you that I had not heard of the ADCIRC, so I am mystified why you believe I think it is junk. Hang on, let me go take a look …
OK, thanks for waiting. Contrary to your claim, ADCIRC is not a GCM as the term is commonly used. Instead, it is a “Coastal Circulation and Storm Surge Model”, which is a very different beast. It has a number of huge advantages over global climate models. It is solving a much smaller problem in both time (weeks/months) and space (a section of a coastline). The problem has far fewer variables (e.g. no cosmic rays, no solar variations, no biosphere responses). The hydraulics and their equations are well understood. The model can be predominantly physics based. The results can be tested and compared to reality, both historical and more importantly, on wave tables. This last is a huge advantage.
So yes, I would expect the ADCIRC results to be good. And I strongly support their use by the Army Corps of Engineers, as you mention.
But you are making a very, very serious mistake if you think that models like the ADCIRC are related to GCMs. Well, I guess they’re related, they’re both models, but the current global climate models are more like some related clan of hereditarily inbred, developmentally disabled, genetically damaged cousins of models like the ADCIRC. You know those relatives, the inlaws you don’t talk about that can’t read or write and try cover it up.
The rate of sea level rise has been falling lately, so it’s not at all clear what studies you mean. Citations beat pointing at the Arctic and waving your hands.
Agreed, and that comes with the territory. Do big projects, you have to deal with politics.
Like I said, so far we haven’t disagree about much except whether I understood cyclonic storms and their effects.
Again, agreed. Best people for building/stabilizing beaches are Holmgren Technologies. There’s been lots of failures by other folks, the shifting banks are a bitch, which has made many areas resistant to further coastal work. Also, often with sand one man’s gain is another man’s loss …
Absolutely.
In the first sentence, it’s your humble opinion, and in the second sentence, it’s for sure? … just saying.
Again, vague. Sea level rise has a steric component, the amount that is due to the temperature change of the ocean. It also has a volumetric component, where melting land ice is added to the ocean. Unfortunately, the sea level budget is not well constrained, although it has been narrowed in recent years. Not sure why you expect a large lag between rising surface air temps and rising ocean temps, is there a sign of one in the records?
Lastly, I’m not sure what a lagging indicator of a potential effect might look like if I saw one.
Dude, you are sooooo last century. In the sixties I learned Alcom. I learned Fortran and COBOL. Moving on in rough chronological order, I learned Datacom. I learned MSDOS. I learned CPM. I learned Basic. I learned C. I learned C++. I learned Pascal. I learned 68000 assembly. I learned Mathematica programming languages, there’s several conceptually different ways to program it, it’s fascinating. I learned LISP. I learned VBA. Within the last decade I learned R.
So Fortran is an old friend of mine. And I agree it should be in a serious scientists bag of tools. But the idea that serious research only gets done in Fortran? It is to laugh.
Here’s the problem. Suppose I have a huge block of data, it is measurements of some variable, with rows being years and columns being months. I’ll call it “MyData”.
In most programming languages, if I want to say take the square root of every datapoint in MyData, I have to declare some variables, then do something that (in pseudocode) looks like this:
numberofyears=Rows(MyData)
numberofmonts=Columns(MyData)
for i =1 to numberofyears;
__for j=1 to numberofmonths;
____MyNewData[i,j]=squareroot(MyData[i,j]);
__next j;
next i;
In R, on the other hand, you say
MyNewData = squareroot(MyData)
As a result, R is infinitely superior to any looping language for handling large datablocks. Think about the time savings in never writing loops again, the ease of debugging. For me, you’re not a serious scientist unless you can read and write Fortran but given the choice, you program in R. It’s free, it runs on all platforms. What’s not to like?
And if you can’t build a car, you shouldn’t complain if a wheel falls off? You are confusing a model’s inner workings with whether it produces diamonds or dust. Non-modelers can certainly find fault with model results. In any case, I’ve coded models and used them firsthand, I abhor using models secondhand, my arms aren’t long enough.
Generally true, but definitely not necessarily true for individual models or classes of models. No model is better than the misconceptions of its programmers.
I know that all models are wrong, and some are useful. I don’t think we disagree all that much, except for your idea that global climate models are anything like those you use in your work.
w.
Willis,
You clearly did not get the storm surge correct as you originally stated;
“The storm surge is the huge area of water under the center of a hurricane that is driven onshore with a hurricane.”
I rather clearly stated that this was NOT the case.
There is no “huge wall of water under the center of a hurricane”.
You need to go back and carefully re-read what it was that I actually stated. Come back then, and I’ll try to clear up any further misunderstandings you may have with respect to maximum hurricane surge and it’s location relative to the eye of the storm.
The pressure bulge is only ~3 ft at most, at the maximum pressure drop at the center of the storm, and it’s incredably simple to figure this out this number, I’ll leave it as an elementary exercise for you to figure out how that number is derived.
Since I’m a Research Hydraulic Engineer, let’s just say it’s like 2 + 2 = 4, but even you should be able to figure it out in less then a few seconds, even.
Anecdotal references are totally meaningless, and clearly subjective, without models, and much more specifically data, on actual storm surge events.
But do carry on, with several pages of anachdotal references, I won’t be wasting any more time on those thoughts though.
Second, as to ADCIRC, it is a general circulation model (GCM), which is what I clearly stated.
GCM can be either a global circulation model or a general circulation model, same acronym for both, get it? Where I’m from, a global circulation model is a subset of a general circulation model.
Beach erosion?
I’m not, nor have I ever been, a Sand Engineer. Do not get me started on Sand Engineers, they’re much worse than climate scientists, even.
Sea level rise?
Not going to go there either, nothing you’ve stated is news to me, plus I know way more than you’ll ever be capable of knowing in said subject matter. I do happen to have worked for the USACE ERDC CHL, and CRREL before then. My thesis was all about stratified flows, something called OTEC, dealing with salt water and temperature gradients even, hundreds of experiments with both even. 🙂
Dude, all engineering and scientific software, as used on all the world’s supercomputers is STILL WRITTEN IN FORTRAN! Big iron is nearly 100% Fortran, still writes the fastest code possible, short of assembly coding (And who does that anymore? Seriously.).
Now on the desktop we have dozens of flavors of *NIX in 64-bits, the main one being OS X, and Windows 7 (I’ve been 64-bit Windows for over five years now).
Do I need to point you to Intel’s (64-bit and multi-core and vectorizable) or PGI’s (CUDA (or still vectorizable without it) and multi-core and 64-bit) modern Fortran compilers? Or the Fortran 2003/2008 standards?
There are literally dozen’s of 64-bit Fortran compilers on the market today, and two free 64-bit Fortran compilers (G95 and gfortran).
So, for instance, FFTW, is written in Fortran, and is the algorithm that MATLAB uses to solve large vector based FFT’s.
C99 (that’s 1999, as in the year of adoption) finally got complex numbers and IEEE double precision floating point (64-bit longs).
1999? 🙁
That’s all folks, this is now page 2, you won’t be hearing from me again in this thread (with the very slight minor exception of clearing up any misunderstandings you might still have on storm surge).
Bye-bye.
EFS_Junior says:
March 1, 2011 at 9:57 am
You are serious? That’s your nitpick? That I said that the storm surge is the water under the center of a hurricane, when in fact it is both under and in front of the hurricane?
You come back with the asinine statement that there is no “huge wall of water” … well, duh, EFS_Junior, I didn’t say there was a huge wall of water.
Next, you say:
That’s your nitpick on this one? Everyone in the climate science field uses GCM for a global model. You say you know better, you say where you come from, a local coastline model is called a GCM … but you’re not playing in your own backyard here. You may call it that in your small corner of the planet. Out here in the big world, what you may call it means nothing. Get with the program. Around here, we DON’T USE YOUR TERMINOLOGY, and so no matter how right you may be in your own backyard, out here your’re wrong.
Nope. You need to stop being an idiot about small nits that you want to pick. You may be the global expert on storm surges, for all I know. If so, you could likely make a good contribution to this discussion.
But if all you want to do is whine about the location of a storm surge, and try to get us to call a coastal surge model a “GCM”, you’re useless.
Thank god. Your focus on trivialities is typical of AGW supporters. I intend to hold you to your claim that “you won’t be hearing from me again”. Don’t bother to try to “clear up any further misunderstanding”, your style is unpleasant and your insistence that we respect your quaint provincial attitudes about computer models doesn’t work here in the real world. In other words, you’re wasting your time casting your pearls of wisdom before us swine, we don’t care …
w.