From the University of Southampton:
The tides they are a changin’
Scientists from the University of Southampton have found that ocean tides have changed significantly over the last century at many coastal locations around the world.
Increases in high tide levels and the tidal range were found to have been similar to increases in average sea level at several locations.
The findings of the study are published online in the journal Earth’s Future.
It is well documented that global average sea levels are rising; but tide levels, have generally been considered to have undergone little change on decadal time scales. It is also often presumed that tides will not change much over the next century. As such, long-term changes in tides are not accounted for in many practical applications and scenarios affected by rising sea levels.
The team used a dataset of 220 sea level records from around the world, which ranged in length from 30 to 150 years. By extracting the tide data from the other components of sea level, they were able to isolate changes in 15 tidal levels by looking at different records of high and low waters from the tidal signal.
Lead author Robert Mawdsley, postgraduate research student in Ocean and Earth Science, says: “We find that at many sites around the world significant changes in tidal levels have already occurred, and at some sites the magnitude of the changes are comparable with the increase in global mean sea level through the 20th century.
“For example, increases in average high water of over one millimetre per year have occurred around the world, including Calais in France, Manilla in the Philippines, Wilmington in the USA and Broome in Australia. Increases in mean high water of approximately half a millimetre per year occur at UK sites, such as Heysham, Millport and Port Patrick, all of which are around the Irish Sea. Decreases in mean high water and tidal range occur at many sites around the UK, including Milford Haven, Lowestoft and Ilfracombe. This has potential impacts on energy extraction, such as the tidal lagoon in Swansea Bay.”
“The magnitude and global distribution of changes in tides have been hinted at before,” said co-author Dr Ivan Haigh, Lecturer in Coastal Oceanography. “However, here we have been able to assess changes in different tidal levels, which are used for many practical applications. Tides exert a major influence on the coast, affecting coastal flooding and erosion, navigation, tidal energy extraction, sediment movement and the extent of species in coastal ecosystems. Therefore, the changes we have identified have wider ranging practical and scientific implications, particularly if they increase in the future.”
“The cause of these changes is complex and appears to be a combination of mechanisms from local to global, with the primary driver being the rise in sea level associated with climate change,” says co-author Dr Neil Wells, Associate Professor in Physical Oceanography and Meteorology. “Further research is required to more fully understand the mechanisms causing these changes and to understand how tides might further change in the future.”
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I can’t believe no one has pointed out the total and utter stupidity of this. Here two a quoted comments from the article.
By extracting the tide data from the other components of sea level, they were able to isolate changes in 15 tidal levels by looking at different records of high and low waters from the tidal signal.
The cause of these changes is complex and appears to be a combination of mechanisms from local to global, with the primary driver being the rise in sea level associated with climate change,
Okay people look up tides and what causes them. Are you ready for this…. It is the moon’s and the sun’s gravity. It has nothing to do with climate, nothing. In fact the moon is slowly moving farther from the Earth and thus tides are slowly getting smaller. The shape or topography of the sea coast and depth of water next to the beach will affect tides.
Now storm surges are a different thing, but they are not tides.
Good grief where do these people go to school.
Storm surges are not tides but they are also determined by coastal geometry (e.g., Sandy’s storm surge enhanced by the New York Bight) and coastal topography (shape of the sea floor). There are also natural changes over time (e.g., the Mississippi Gulf coast from pre-Camille to post-Katrina) and manmade changes (e.g., the dredging of harbors and shipping channels in the Chesapeake Bay) to consider.
The tide at Calais changes 8,480mm every 6 hours and they can measure it to within 1mm?
And then there is Broome, ever seen the tide at Broome? 9.2 metres, again 1mm.
I have lived and worked at the high tide mark in Broome over the past 30 years, a 1mm rise each year for the past 100 years, would have the Chinatown shopping precinct underwater at high spring tides. It isn’t. Even BoM built new facilities close to the high tide mark. http://pindanpost.com/2011/05/03/underwater-broome-developers-dont-think-so/
when I used to watch waves ( 10 years or something ) it seemed like ever fourth one was bigger than the previous three, would try to catch that one to get on to the slipway which was at right angles to the flow and so a little bit tricky
Where I bodysurf in Florida, it is every seventh wave. Or so. Of course, our offshore reef messes things up unless only really big slow roller swells from some offshore storm…
Which is why sat altimetry is imprecise. Is continuously integrating a return signal over the wavy sea surface. Darned ocean won’t stand still for its picture…
the affection for the sea is a real thing bro
Yup. I sail too. Don’t tell Willis. Oh, and snorkel and scuba reefs. Heck, why just stay on dry land?
@ur momisugly Rud, I blame it on the Dutch, they probably ringed and diked in another polder, pumped out the seawater raised the sea level but smart buggers that they are, are now using the rising CO2 levels to grow more fruit and vegetables!
Nope.
I refer you to a WUWT article about the Maldives, supposedly threatened by rising sea levels.
http://wattsupwiththat.com/2009/03/19/despite-popular-opinion-and-calls-to-action-the-maldives-is-not-being-overrun-by-sea-level-rise/
Quoted from the headline post;
“For example, increases in average high water of over one millimetre per year have occurred around the world,
including Calais in France,
Manilla in the Philippines,
Wilmington in the USA
and Broome in Australia.
Manila, S. Harbor tide gauge data per PSML.
http://www.psmsl.org/data/obtaining/stations/145.php
[quoted ]INCREASE IN TREND IN MSL RISE SUSPECTED TO BE DUE TO DEPOSITION
FROM RIVER DISCHARGES AND EXCESSIVE RECLAMATION ALTHOUGH SUBSIDENCE
NOT TOTALLY DISCARDED (LETTER FROM COAST AND GEODETIC SURVEY 13/5/1987).
My comment ; Manila tide gauge data was flat until around 1960 when it began a rising trend.
See above PMSL note.
Broome; in Australia’s NW per PMSL data;
http://www.psmsl.org/data/obtaining/stations/1159.php.
The 1997/8 super El Nino sea level rise for the western Pacific and it’s delayed flow on
effects into the Indian Ocean is very obvious in the Broome PMSL data.
________
Perhaps this is the real reason for the supposed increase in tidal range levels at least in the western Pacific.
A shift in western tropical Pacific sea level trends during the 1990s
Merrifield, M. A., J. Climate, 24, 4126-4138, doi:10.1175/2011JCLI3932.1, 2011.
Abstract;
Pacific sea surface height trends from satellite altimeter observations for 1993-2009 are examined in the context of longer tide gauge records and wind stress patterns. The dominant regional trends are high rates in the western tropical Pacific and minimal to negative rates in the eastern Pacific, particularly off North America. In the western tropical Pacific, tide gauge records indicate that the recent high rates represent a significant trend increase in the early 1990s relative to the preceding 40 years.
>>This sea level trend shift in the western Pacific corresponds to an intensification of the easterly trade winds across the tropical Pacific. In the eastern Pacific, tide gauge records exhibit higher-amplitude decadal fluctuations than in the western tropical Pacific, and the recent negative sea level trends are indistinguishable from these fluctuations.
The shifts in trade wind strength and western Pacific sea level rate resemble changes in dominant global modes of outgoing longwave radiation and sea surface temperature. It is speculated that the western Pacific sea level response indicates a general strengthening of the atmospheric circulation over the tropical Pacific since the early 1990s that has developed in concert with recent warming trends.<<
I should have added that Broome’s tides in NW Australia range from low tide to high tide through at least 8.2 METRES [ 26.9 Ft ]
It is the largest tide range in Australia.
From this the paper’s authors can apparently diferentiate and derive tide measurement variations at Broome down to a millimeter or so.
http://tides.willyweather.com.au/wa/kimberley/broome.html
Once every 18 to 20 years, Broome has a tidal movement of over 10 metres. The 1998 El Nino gave us a cyclonic near miss with Cyclone Rosita, a Cat 4 system that destroyed Eco Beach Resort, about 40 km south. The previous wet season saw a 5 hour period of almost 20 inches of rain. I guess that was the warmest period of the last 80 or so years.
This year is almost as warm, but no cyclones this season with just a month to go. That must be some sort of record.
2011 saw the biggest spring tides in nearly 20 years. Fortunately, no cyclone arrived during spring tides. The town’s activities revolve around tides. It’s especially interesting when the tide is out: http://pindanpost.com/2014/03/05/cable-beach-mud-reef-garden-part-2/
I’ve been in the delta of the Red River of the North, where its distributaries enter Lake Winnipeg – a location on one of the the continents major wild duck and goose flyways. Because of the long N-S length of the lake, a north wind, naturally common during the bird hunting season, can pile the water up in the delta up to 3 feet (anecdotally) and you can have a very uncomfortable time sloshing around in the square miles of reeds and deepened water channels on a cold cloudy November day. As kids we did this in running shoes having no waders, which can be dangerous to wear if you trip and fill them up – we carried dry clothes and shoes in the car. I had a Springer Spaniel to fetch for me, but when the winds were a bit too strong, we waited for a lull seated on top of a muskrat reed hut because her short legs meant she had to swim too much.
Surely, tide measurements must also be confounded by variations in winds and longshore currents. The measurements also vary with air pressure Do they collect all this data at the gauge stations, too? If not, how do they remove all these effects to get at ~1-2mm sea level rise? They simply can’t. If we are worried about 5-6m of sea level rise per century, we don’t need to measure with a micrometer each day to detect trouble.
IPCC worries about that much occurring in year 2500.
“For example increases of over one millimetre have occurred around the world”. Sorry, call me a crazy skeptic, but 1mm a year??? 1cm per decade, 10cm per century. 4 inches per century. The margin of error in this must surely negate the assertion. What the hell are we freaking out over 10cm a century for anyway?
1/2 mm floors me. whats that , the diameter of a grain of sand? Some very sophisticated equipment would be required to measure the sea to that kind of tolerance. I am skeptical that they have that kind of technology. they must have determined that by assuming or measuring 1″ over 50 years.
In the long term we can expect around 20 metres of global sea level rise per degree C of global warming, with peak rates of multiple metres per century. The crucial question is how much effort and resources we put into adaption vs mitigation. It’s easy to say “We’ll just wait and see, and deal with what happens”, but that’s something which is a lot easier for rich countries than poor ones.
The globe has stopped warming for now so the assumed trend is on hold and may reverse.
In fact global warming accelerated around 2000AD, and there is a lot more ‘in the pipeline’.
There is ice in the pipeline. Arctic and Antarctic sea ice extent [are] both expanding. AGW RIP.
Repetitive: IPCC worst, worst, worst case GCM sees that sort of rise stretching out to year 2500 and it also requires major ice sheet melting. Think 485 years is enough time to adapt?
We’ll definitely adapt, but it will be costly and disruptive, and we’ll lose a lot of land (plus of course sites of scientific and cultural value). We could be condemning our kids and grandkids to have to deal with half a metre of sea level rise each decade, for centuries.
20 meters per degree??? So the assumed warming over the last 150 years or so should raise the sea level what 90 to 120 feet? And Gore buys more ocean front property with OPM.
You have to remember that we’re only now just exceeding the temperature of the Holocene Thermal Maximum. As the last deglaciation came to a halt and global temperature leveled off and started to slowly decline, global sea level rise just about stopped, which means that the world’s ice was roughly in equilibrium with the climate up to the 19th Century. I suggest that it’s the warming from now on which will produce the really large rises in global sea level. I’m happy to defer to anyone with a better analysis of the situation though.
Icarus:
Horse grunt. Temperatures are at the MWP level. Holocene max was 2-3°C higher than now. You have imbibed a bunch of alarmism.
Icarus says, “You have to remember that we’re only now just exceeding the temperature of the Holocene Thermal Maximum”
—————————————————-
An assertion with zero evidence, and much evidence against. We are nowhere close to the Thermal Maximum. it is well accepted that todays SL is one to three meters below the Holocene high.
Here is one link. Many more if you wish.
http://www.cato.org/blog/evidenced-based-sea-level-rise-projections-remain-low
Icarus – so add ONE grain of sand to your foreshore dykes each year and “Voila!” No problemo. Come down from the sun and check out that bouncy little flexible ball we live on. (Think of a water balloon flying through the air with all its oscillations in flight.) You think you are standing on solid ground – but like all climate scientists, you aren’t. The earth is quite flexible – and adaptable. “What? Me worry?”
http://en.wikipedia.org/wiki/Alfred_E._Neuman
http://www.bing.com/images/search?q=What+Me+Worry+Images&qpvt=What+Me+Worry+Images&FORM=IGRE
You ever ask the “poor countries” what they really need ?
What they worry about ?
I can almost guarantee it ain’t millimeters of sea level rise.
Probably more to do with the guys holding the guns and machetes.
Fair point… although individuals are already losing their land, homes and livelihoods to rising sea level in low-lying countries.
Icarus:
Do not let reports of local coastal subsidence fool you.
Icarus,
Seeing as sea level has not risen enough to affect anyone (with enough sense to plan for 1/4″ of sea level rise in their lifetime), personally, I’d be investing in chain mail to thwart the machetes.
Just like olden times.
20 metres per degree? The temperature is supposed to have risen 0.7C in the last 60 years. Last time I looked St Kilda pier and the 14foot jetty that I played on in the mid 50’s were still above water so there is something wrong with your calculations.
Obviously it doesn’t happen instantly. It takes a long time to melt thousands of cubic kilometres of solid ice.
Icarus
‘individuals are already losing their land, homes and livelihoods to rising sea level in low-lying countries’
How about listing a few of those places you refer to, and telling us how much the sea level worldwide has risen to cause those problems?
“We’ll just wait and see, and deal with what happens”
We’ve already done this. These doom and gloom predictions have been going on for 35 years running and none of them have come true. I think we’ve had plenty of time to see they these theories are bogus.
Sea level rise is at the top of the predicted range, so that’s not very reassuring.
http://images.sodahead.com/profiles/0/0/2/0/7/6/2/8/5/sealevelvsipcc-56452112061.jpeg
Icarus:
Sea level guages on stable coasts show no rise, so relax. Do not pay any attention to satellite sea level data, which is unreliable.
“Sea level guages on stable coasts show no rise, so relax.”
“Do not pay any attention to satellite sea level data, which is unreliable.”
do you have any evidence to support either to these statements?
*of these statements 🙂
See NOAA Mean Sea Level Trends, plotted for each gauge. Some locales, such as Grande Isle or Chesapeake Bay area are subsiding and the guages show a rise in SL. Neah Bay is being uplifted hence shows falling sea level. NE coast shows rise, which has been variously attributed to isostasy or change in ocean currents.
Satellite altimetry is unreliable for raw data accuracy problems and the fact that some places, like the U of Colorado or NOAA plot the data on a sloped base.
Global warmers have no qualms about fabricating data and presenting it as honest.
@mpainter
What I mean to say is, do you have any evidence of sea level gauges on “stable coasts” that show no rise in sea level as you claim?
@mpainter
“Sea level gauges on stable coasts show no rise, so relax.”
So do you have any evidence as to which gauges are on stable coasts and also show no rise then?
so you don’t have evidence of any sea level guages on stable coasts that show no rise?
Bevan, how long have you had your disability?
See above for evidence.
mpainter,
So let me see if I am clear on this. Satellite data relating to sea levels is unreliable, so we should rely on sea level gauges. When it comes to temperatures, however, it is just the opposite – ground level thermometers are not reliable, but satellite temperature data is. Do you have evidence to back up those opposite conclusions?
Satellite altimetry is a different measurement from satellite temperature measurement. Do you find that difference difficult to grasp? And do you require evidence that these are different satellites, different measures, etc.?
NOAA tide gauges are reliable, as the data has not been fabricated as in surface temperature data. There are several score of these on US and Canadian [!] coasts. For each gauge is plotted a separate Mean Sea Level Trend. These show a flat sea level trend for the past 15-20 years on the west, Gulf, and east coasts, except for 3-4 gauges at locales that are subsiding, such as Grande Isle, La. The Chesapeake Bay region experiences subsidence and those gauges record sea level rise.
For reliable information on sea level trends, I rely on gauge data. Satellite altimetry is a joke.
Oh, Chris, why ask for evidence?
Rud Istvan’s comment above at 2:53 pm, March 6, gives the information in altimetry satellite data. This shows that it is good for +/- 3.5 cm.
The reliability of surface temperature measurements is doubtful because of the uncertain accuracy but mostly because the keepers of the data cook it to achieve confirmation bias. This is done by lowering past records and raising current data. This is well documented.
Icarus. Can we have your reply to my post above please?
So we have had 0.8C temp increase since about 1750. Maybe only half that is anything but unwarranted adjustments. But where did sea level increase by even 8 meters? Sheesh.
I see, WATTUP had a thread on the mysterious failure of the envisats and the mysterious revision of the envisats sea level data to changing falling sea level to rising sea level.
http://wattsupwiththat.com/2012/04/12/envisats-satellite-failure-launches-mysteries/
P.S. Global sea level is now falling, why it is falling is due to an interesting phenomena and is directly related to what causes the solar TSI to change. As Leif noted TSI for some unexplained reason has risen when the solar magnetic cycle slowed down which is the opposite of what is expected based on the standard solar model (the standard solar model is incorrect). TSI is now starting to drop and will continue to drop.
(See this site, sun, recent TSI)
http://www.climate4you.com/
My cousin was the pilot on a PBY flying boat in the Pacific during WWII, and he said they would time their launch into the sky on a specific wave crest which was higher then the rest. I don’t recall which one it was.
What is even more fun is landing a seaplane on 3 to 4 foot rollers – gets really interesting trying to get it to “stay” on the water. You know you might be in trouble when 20 or so people are standing on the dock to watch your plane try to land …
Think of them as witnesses to your flying skills, then ask if any of them want to do a touch-n-go with ya 🙂
A thousand years ago as a beginning pilot we learned that navigating was measured with a micrometer, marked with a crayon, and then cut off with an axe. An approximation was all you ever got. The same is currently true with sea level.
Abstract alone says a mouthful…
“…For the tidal levels assessed, between 36% and 63% of sites had trends significantly different (at 95% confidence level) from zero. At certain locations, the magnitude of the trends in tidal levels were similar to trends in mean sea level over the last century, with observed changes in tidal range and high water levels of over 5 mm yr−1 and 2 mm yr−1, respectively. More positive than negative trends were observed in tidal ranges and high water levels, and vice versa for low water levels. However we found no significant correlation between trends in mean sea level (MSL) and any tidal levels”…”
So there you have it. Either most of the assessed sites did or did not have any change (somewhere between 37% and 74% had no significant trend). Some followed trends of the past century. More high water levels went up rather than down, and more low water levels went down rather than up. And there was no correlation between tidal levels and sea level.
Groundbreaking stuff.
Well at least Blackpool tower hasn’t yet suffered the same fate poor Liberty did when the photoshoppers drowned her.
Sorry, could not get beyond the open blurb — the tides they are a changin”.
My mind switched it to — the lies they are a changin’ — which about sums up the history of CAGW.
Will now go back and read the article.
Eugene WR Gallun
An engineer is a person who passes as an exacting technical expert on the basis of being able to turn out with prolific fortitude, infinite strings of incomprehensive estimates calculated with microscopic precision from vague assumptions and debatable figures taken from inconclusive data obtained with recording devices of problematical accuracy by uninformed persons of doubtful reliability and questionable mentality under the influence of ….
So what is a climate scientist?
I thought you guys added a 50% “fudge factor” 🙂
Q: So what is a climate scientist?
A: A person that flunked out of Engineering.
That is an unfair criticism of anyone who flunked out of Engineering.
To be fair, Bill Nye and Pachy made it through. Then again, we have these guys.
http://www.ae911truth.org
A paid official who works by fixed routine without exercising intelligent judgement
Oh, and in case you wondered, “I are one.” 😉
Me, too. And w/ that BSME came demonstrated competence in: chemistry, physics, heat transfer, thermodynamics, statistics, calculus, algebra, etc. Get the picture? A “climate scientist” is just a snake oil peddler trying to impress everyone that they have some kind of specialized or inside knowledge no one else has.
( I do presume )
Hockney is interested in theatre doing Jarre and something else ( about television )
then I notice Picasso wanted to be a playwright.
giving a form to reality that they liked the look of
do you see ?
people try to imagine things
why do they do that ?
As I recall the rates of sea rise went up when they added in the subsidence of the floor below the sea thus re defining sea level relative from the bottom of the sea bed rather than the surrounding land.
Of course this exaggerates the claimed rise
If something is perfect why would somebody try to change it?
increases in average high water of over one millimetre per year
*****************************************************
ONE mm….
1
oooohhhh thats a huge amount, I bet their instrument error range more than that.
The two pix at top show a sea level change of several feet in 4 hours and 40 minutes. Concerns about millimeters in decades is asinine.
It’s akin to warnings about temps changing 2 degrees, when temps change 20 degrees EVERY DAY.
1mm a year rise cited in this study for the fast rising gauges is less than the ambient rise in sea level BEFORE AGW.
So, sounds like the centuries long rise is sea level is slowing.
I did a quite scan of this…am I missing something ?
Mt. Everest is also rising. I suppose that is also due to CO2 emissions. It never ceases to amaze me how people can come up with dogmatic statements about measurements of fractions of a millimeter or hundredths of a degree when we have only had the instrumentation to measure this accurately for the last 35 years. (I don’t even think there was an operational laser until 1957).
Reading this paper reminds me that the sea level debate needs an audit similar to Anthony Watts’ Surface Stations research.
Even after their reported “quality control” measures, most of the data used by the authors remains subject to large potential errors. For example, many of the tidal gauges that survived their culling process still had enormous uncertainties due to sea wall construction, land subsidence and tectonic activity, estuarine environments, dredging and construction, etc. Although they were aware of these potential problems, they still report statistical confidence based upon the precision of the mathematics employed, rather than the accuracy of the actual data.
So we have land subsidence and erosion in play.
The great assumption over sea levels is that the land is static. Shorelines, in particular.
If you look at the islands and atolls making up the Hawaiian Island chain, the biggest are where the hotspot is still making land. Where the land has moved north and west of the hotspot, they get smaller and eventually become seamounts. Does anyone know how large they were during initial formation?
Any kid who’s ever made sandcastles knows water always wins. So is the land actually getting higher (as in the Himalayas and where vulcanism is active, or is the land sinking, as is the fate, apparently of all dormant sea mountain islands?
And what about the “permanence” of so-called continental shields? How do we know they aren’t rising and falling on some scale?