As we surmised in earlier posts, the crozon.colorado.edu website was a test run. Here’s the newest graph from the revised http://sealevel.colorado.edu/
They write about the update:
Welcome to the new webpages from the University of Colorado sea level group! We apologize for the delay in updating our sea level releases, but the transition to these new web pages took longer than we thought. In addition, we have made many improvements to our data (new orbits, new tide model, new corrections) which ultimately had little effect on global mean sea level, but brought us up to date with the latest advances in the field.
One important change in these releases is that we are now adding a correction of 0.3 mm/year due to Glacial Isostatic Adjustment (GIA), so you may notice that the rate of sea level rise is now 0.3 mm/year higher than earlier releases. This is a correction to account for the fact that the global ocean basins are getting slightly larger over time as mantle material moves from under the oceans into previously glaciated regions on land. Simply subtract 0.3 mm/year if you prefer to not include the GIA correction.
You may also note that rate of sea level rise over recent years has been less than the long-term average. This is believed to be due to the recent La Nina’s we have been experiencing, though research on this is continuing. We will soon add a plot to the web site illustrating this effect.
Let us know if you spot any bugs in the new web pages. Thanks for your interest!
Comments welcome.
Welcome to the new webpages from the University of Colorado sea level group! We apologize for the delay in updating our sea level releases, but the transition to these new web pages took longer than we thought. In addition, we have made many improvements to our data (new orbits, new tide model, new corrections) which ultimately had little effect on global mean sea level, but brought us up to date with the latest advances in the field.
Yeah, right. Do they make adjustments for water extraction?
I forgot to bold
“(new orbits, new tide model, new corrections) “
I notice that much of the Topex trace is below the line – then much of Jason 1 is above the line ?
Has anybody double checked their 2002 join Topex to Jason 1 ?
This was to be expected. Hide everything that dilutes the message. Under the carpet!
Long term it cannot work. The pile under the carpet is getting bigger and bigger…
I just hate it when people tinker with long term data. This looks like hide the decline part 2.
So to get to the IPCC predictions of sea level rise to 2100 we need some acceleration in the yearly rise. I see no such acceleration. In fact there is a recent deceleration. The next few years will be interesting.
I’ve made a small essay regarding the rate of rise:
http://ecotretas.blogspot.com/2011/05/rate-of-sea-level-rise-going-down.html
It’s going down and FAST! In my opinion, the data was stopped because in cycle 2010.7415 the trend was 2.956158611 mm/year, just enough to round it to 3.0
They have had these months to re-engineer the values so they are at least still bigger than 3.0 mm/year!
Ecotretas
One important change in these releases is that we are now adding a correction of 0.3 mm/year due to Glacial Isostatic Adjustment (GIA), so you may notice that the rate of sea level rise is now 0.3 mm/year higher than earlier releases.
Hocus pocus!
Why don’t they give sea level relative to shorelines where it counts to us inhabitants? Maybe it’s that some are rising and some are lowering due to isostacy and drift and would mean an inconsistent mishmash of positive and negative numbers to average?
Is anyone positively, absolutely, no doubt about it, convinced they can even measure a 3 inch rise in sea level, over any given amount of time, for the entire world?
I imagine Mike Mann did some decentered PCA to calculate that adjustment for them… When the data is not behaving, they just call in a cleaner from AGW team headquarters.
A 100% transparent adjustment based on legitimate observations and folks here are still complaining. It’s not like the Colorado folks are trying to slip one past you.
So La Ninia’s cause a drop but El Ninio’s don’t contribute to the rise?
If the mid 2011 number comes in the same as the last bit of 2010 then I’d say that trying to fit a straight line to the data is folly. Then the plot would have more of the characteristics of a sine wave with a period of about 30 years rather than a straight line
Why do they insist on adjusting empirical data. Sea level is sea level. If I put water into my swimming pool and measure that level on a regular basis, which I do, I don’t make adjustments for the movement of the walls due to weight of water or the descent of the whole pool relative to the surrounding soil. The level is what it is. The data is what it is. LEAVE THE BLàèDY DATA ALONE! It’s cheating. Nothing but cheating. What are the objectives behind sea level measurement? Is it to calculate the point at which we need to be build our houses further in land or on stilts? Is it to allow us to change the profiles of our ports to keep them open? or Is it to prove that the glaciers are melting and we need more funds.
So they are adding a constant to it…
..and it’s still going down
Buzz Belleville says:
May 6, 2011 at 4:18 am
A 100% transparent adjustment based on legitimate observations and folks here are still complaining. It’s not like the Colorado folks are trying to slip one past you.
Just because it’s “transparent” doesn’t make it right!! Puuleeze!!
@Barry Foster Belleville
It depends on the point of this measurement. Typically, people think about sea level rise being how much coastline on average is being reclaimed by the sea because that is what is most important to people on the coast. If that’s what this is supposed to be measuring, adjusting for changes to the volume of ocean space is not helpful.
I have nothing against measuring volume. That would be interesting to track. I’m not sure we have the technology to really do it with any accuracy though.
More hide the decline pseudo-science.
If this is supposed to be a record of sea level it should be showing sea level. It is not supposed to be a record of ocean volume. GIA is a fraud. This is no longer a measure of sea level but some other metric.
People, governments etc. are concerned about sea level as it relates to land. That is what all the alarmism about sinking atolls and flooded coastal plains is based on.
If we want to infer sea volume from sea level *then* there may be a need to apply some adjustment. At that point we need to look at where these adjustments come from. Let me guess… simplistic computer models.
You do understand, fellow posters, that the Colorado page is not just adding 0.3 mm to the current year to show a greater rise in sea levels. It’s adding o.3 mm to all plotted points. It has no effect on the rate of rise.
And the adjustment for GIA is based on peer-reviewed scientific literature, not some nefarious whim.
Regarding the glacial adjustment, the glaciers were primarily on the land. The extra weight pushed down the land and the primarily non-glaciated ocean bottom would have increased slightly or bulged up in compensation.
Now that the glaciers are gone, the land is rising again and the ocean bottom is sinking back to its non-glacier position. There is also the weight of the extra water (which was formerly on land in glaciers) which is now in the ocean which is also pushing down on the ocean bottom.
The overall average depth of the oceans is sinking enough to lower sea level by 0.3 mms per year.
Since sea level is actually measured at increasing 2.7 mms/year, the actual volume change of the water in the oceans must be 3.0 mms/year.
Note that the sea level is actually only increasing by 2.7 mms/year.
(So I think it really shouldn’t count here. If you are going out 100 years and trying to say New York will be flooded by the ocean, you shouldn’t add in the Glacial Isostatic Adjustment because the sea level will not actually increase as a result of this adjustment).
“You may also note that rate of sea level rise over recent years has been less than the long-term average. This is believed to be due to the recent La Nina’s we have been experiencing, though research on this is continuing.”
So, La Nina is affecting the heat content of the Pacific.
I’ve been told that La Nina only causes redistribution of heat. Cold water coming up from the deep and warm water moving away to the west. Not a heat loss in the Pacific causing thermal contraction.
I say look to the PDO!
“NOBODY expects the Glacial Isostatic Adjustment!
Our chief weapon is surprise…surprise and fear…fear and surprise….
Our two weapons are fear and surprise…and ruthless efficiency….
Our three weapons are fear, surprise, and ruthless efficiency…and an almost fanatical devotion to the Pope….
Our four…no… Amongst our weapons…. Amongst our weaponry…are such elements as fear, surprise…. I’ll come in again.”
With respect to Monty Python
@ur momisugly steven richards: it’s not a matter of right or wrong but of comparing like with like. The ocean basins are physically getting larger which – all by itself – is reducing sea levels by about 1.2 inch/century. This is before you can get an accurate picture of the important stuff such as the effect of thermal expansion and the rate land-based ice is melting.
Surely you are not suggesting this should just be ignored – good science means that it has to be recognised for what it is. To compare like with like I suggest it’s better that the figures are adjusted, otherwise we will all have to remember to make manual adjustments every time we look at the data.
I also hope it will later be possible to make accurate adjustments for the effects of thermal expansion, so we can finally get an accurate handle on whether there is any change in the rate at which land-based ice is melting (ie. whether global surface temperatures have truly risen or not).
We have gone completely bonkers. Our researchers have succumbed to the idea that every natural phenomenon must have human causes. They have even added sacrificial austerity and demands for tithe to the backs of peasants.
Turn the money changing table on its head and kick the tax man out of the courtyard. Else we will be forced to join the masses at this temple of research. Eisenhower had it right all along.