From the NASA Jet Propulsion Lab
NASA Satellites Detect Pothole on Road to Higher Seas
An Update from NASA’s Sea Level Sentinels:
Like mercury in a thermometer, ocean waters expand as they warm. This, along with melting glaciers and ice sheets in Greenland and Antarctica, drives sea levels higher over the long term. For the past 18 years, the U.S./French Jason-1, Jason-2 and Topex/Poseidon spacecraft have been monitoring the gradual rise of the world’s ocean in response to global warming.
While the rise of the global ocean has been remarkably steady for most of this time, every once in a while, sea level rise hits a speed bump. This past year, it’s been more like a pothole: between last summer and this one, global sea level actually fell by about a quarter of an inch, or half a centimeter.
So what’s up with the down seas, and what does it mean? Climate scientist Josh Willis of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., says you can blame it on the cycle of El Niño and La Niña in the Pacific.
Willis said that while 2010 began with a sizable El Niño, by year’s end, it was replaced by one of the strongest La Niñas in recent memory. This sudden shift in the Pacific changed rainfall patterns all across the globe, bringing massive floods to places like Australia and the Amazon basin, and drought to the southern United States.
Data from the NASA/German Aerospace Center’s twin Gravity Recovery and Climate Experiment (Grace) spacecraft provide a clear picture of how this extra rain piled onto the continents in the early parts of 2011. “By detecting where water is on the continents, Grace shows us how water moves around the planet,” says Steve Nerem, a sea level scientist at the University of Colorado in Boulder.
So where does all that extra water in Brazil and Australia come from? You guessed it–the ocean. Each year, huge amounts of water are evaporated from the ocean. While most of it falls right back into the ocean as rain, some of it falls over land. “This year, the continents got an extra dose of rain, so much so that global sea levels actually fell over most of the last year,” says Carmen Boening, a JPL oceanographer and climate scientist. Boening and colleagues presented these results recently at the annual Grace Science Team Meeting in Austin, Texas.
But for those who might argue that these data show us entering a long-term period of decline in global sea level, Willis cautions that sea level drops such as this one cannot last, and over the long-run, the trend remains solidly up. Water flows downhill, and the extra rain will eventually find its way back to the sea. When it does, global sea level will rise again.
“We’re heating up the planet, and in the end that means more sea level rise,” says Willis. “But El Niño and La Niña always take us on a rainfall rollercoaster, and in years like this they give us sea-level whiplash.”
For more information on NASA’s sea level monitoring satellites, visit: http://sealevel.jpl.nasa.gov/ , http://sealevel.colorado.edu , http://www.csr.utexas.edu/grace/ and http://grace.jpl.nasa.gov/ .
h/t to WUWT reader “Pete”
==========================================
[UPDATE by willis]
I trust that Anthony won’t mind if I expand a bit on this question. NASA adduces the following map (Figure 2) showing where they claim the water went.
Figure 2. GRACE satellite changes in land water. Note that for all of the screaming about Greenland melting … it gained ice over the period of the year. In any case, red and blue areas are somewhere near equal, as would be more apparent if they didn’t use a Mercator projection that exaggerates the blue area in the Northern hemisphere.
The sea level was going up at about 3 mm per year. In the last year it fell about 6 mm. So that’s a change of about a centimetre of water that NASA says has fallen on land and been absorbed rather than returned to the ocean. But of course, the land is much smaller than the ocean … so for the ocean to change by a centimetre, the land has to change about 2.3 cm.
To do that, the above map would have to average a medium blue well up the scale … and it’s obvious from the map that there’s no way that’s happening. So I hate to say this, but their explanation doesn’t … hold water …
I suspected I’d find this when I looked, because in the original press release the authors just said:
“This year, the continents got an extra dose of rain, so much so that global sea levels actually fell over most of the last year,” says Carmen Boening.
When people make claims like that, with no numbers attached, my Urban Legend Detector™ goes off like crazy … and in this case, it was right.
Best to all, thanks to Anthony.
w.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
They’ll fix this pothole with some minor post facto adjustments. Let Hansen have his way with it. It’ll be fixed real soon now.
This gave me a mental image of a Josh cartoon where a cowering, comely mer-lass labeled “Sea Level Data” is trembling as Hansen rubs his hands and smiles…
Nick Stokes says:
August 24, 2011 at 5:29 pm
Thanks, Nick, much appreciated. I see you are correct, they do say “don’t trust Greenland” in the GRACE data itself. Seems goofy to include it on the map in any color but gray if it is known to be inaccurate.
I area-weighted the change from March 2010 to March 2011. I got 1.4 cm for the land average change, which converts to about half a cm for the corresponding ocean change. This (if correct) only explains about half the change in the ocean level.
The “if correct” part is crucial. I haven’t calculated the error bars on that number, but I suspect that they are rather wide.
w.
“So where does all that extra water in Brazil and Australia come from? You guessed it–the ocean. Each year, huge amounts of water are evaporated from the ocean. While most of it falls right back into the ocean as rain, some of it falls over land. “This year, the continents got an extra dose of rain, so much so that global sea levels actually fell over most of the last year,” says Carmen Boening, a JPL oceanographer and climate scientist.”
It is hard to believe that they found an adult who would utter those words. The moment I read them I said “preposterous – to the point of childishness.”
The water goes up and the water goes down
sometimes it falls on the ground
While it is running to the sea
Be sure to go and take a pee.
Thanks, Willis, for your more analytical approach to the matter.
Jason Salit says:
August 24, 2011 at 11:03 am
“Just to be clear… is this the “adjusted” (plate techtonics aware) sea level we’re talking about or the real sea level as can be evidenced at the coasts?”
Screamingly funny! You know there is no sea level at the coast.
Out of sheer curiousity, why hasn’t the sea level data at http://sealevel.colorado.edu/files/2011_rel2/sl_ns_global.txt been updated since early April? Are they trying to hide yet another decline?
Willis,
Oddly, I also got 1.397 cm, but in my case it was the average on a whole-Earth basis – I added (with cos(lat)*), and divided by sum of all cell areas. That means it is more than enough to explain the dip. But I think I should check more, though the graphs look right. I think one has to multiply by the scale factors provided, though it may not make much difference.
Magnus says:
August 24, 2011 at 3:27 pm
Warmcold, meltfreeze, floodraught, wetdry etc. all caused by CAGW. Now also: risedrop.
Can’t go wrong. And I mean CAN’t
LOL
Gras Albert says: “Does my eyeball analysis of the sea level rise deceive me?”
Nope. Keep in mind, though, that the Sea Level anomaly data lags the “real time” data like SST anomalies by a few months. The University of Colorado’s 2011_rel2 data only brings us to March 2011, while I’ve presented mid-August SST anomaly data already.
Willis,
I did go over my calcs there and found an error – I now get about 6mm difference, fairly close to yours, and also not so far from the change observed. However, I’ve looked at other ranges, and the amount that GRACE says has accumulated on land is not generally a good indicator of sea level change.
Theo Goodwin says:
The water goes up and the water goes down
sometimes it falls on the ground
While it is running to the sea
Be sure to go and take a pee.
I have to go for a pee. Really.
After all is said and speculated, Dr. Morner could be right and the Satellite trend had about 1.5mm added to it way back in the mid 80’s. Remember a recent paper claims that steric sea level rise is close to 0, goose egg, nada, zilch, well, very little anyway. That is because heat is convected up in the oceans and water close to freezing is continuously going to the bottom keeping most of the oceans a nice 1-2c with only a bit at the top warming.
Another Alarmist myth exploding along with their heads.
Anthony and Willis E., thanks again for a good post.
Willis wrote: To do that, the above map would have to average a medium blue well up the scale … and it’s obvious from the map that there’s no way that’s happening.
Is it obvious? I’d be surprised if the conversion of rainfall to equivalent mass/mm of rise/fall is exact, and it looks to me as though there is a net excess of increase over decrease. Have you computed the global mean change? If you are correct (as you might be, it just isn’t “obvious”), do you have any ideas on where the water has gone to?
If there is another La Niña, as seems more likely than not right now, should we expect more sea level decline, or should we expect them to be unrelated?
Ah, I see that Willis Eschenbach and Nick Stokes answered my question. Thanks.
Stephen Wilde wrote: Doesn’t La Nina reduce energy transfer from ocean to air such that ocean heat content and thus ocean volume should RISE and not fall ?
If I understand Willis E.’s thermostat mechanism, the La Niña is associated with increased heat transfer from water to atmosphere (evaporation) followed by increased heat transfer from clouds to upper atmosphere (rainfall.) (Or else El Niño produces the above average evaporation and La Niña produces the above average rainfall. As I understand it, the mechanisms driving El Niño and La Niña are not completely known.) It would seem to take quite a lot of energy to transfer 6mm of ocean surface water from ocean to land, then a large energy transfer to produce precipitation. Josh Willis’ comment, “But El Niño and La Niña always take us on a rainfall rollercoaster, and in years like this they give us sea-level whiplash,” looks to me like something that should prompt Josh Willis to do a lot of calculations about net heat flows.
Have you calculated the expected sea level from the measured warming of the upper 700 meters of the worldwide oceans, as reported by Levitas et al.? What was interesting about this paper was that little warming was observed below 100 meters.
Levitus S., J. I. Antonov, T. P. Boyer, R. A. Locarnini, H. E. Garcia,
and A. V. Mishonov, April 2009. Global ocean heat content 1955-2008 in light of
recently revealed instrumentation problems Geophysical Research Letters 36, L07608,
doi:10.1029/2008GL037155.
According to graphs of the Levitus data which Dr. Roy Spencer posted on his website (drroyspencer.com), Levitus reported that the top 100 meters of the ocean warmed by an average of about 0.25 degrees C and 100-700 meter depths warmed by an average of about 0.04 degrees C over the 53-year period. Levitus did not report any measurements below 700 meters
If the thermal expansion coefficient of seawater is 0.00021 per degree C, then the expansion due to the measured warming should be 100m * 0.25 * 0.0002 + 600m * 0.04 * 0.0002 = 0.01 meters.
Or about 1 centimeter. Do you agree with that calculation?
Of course, it doesn’t count any expansion below 700 meters, but the measured warming at the 700 m depth was only about 0.03 degrees C and the remaining depth of the world’s oceans averages about 2300 meters (3000 meters total.) So the deep water could not have added much more expansion.
So the sea level has fallen over the past year. If the claim is made that this is due to global warming, why hasn’t the sea level gone down prior to the last year? How long has global warming been going on? Is this too simplistic?
Just like the economy hit a pothole.
Willis writes “they do say “don’t trust Greenland” in the GRACE data itself.”
I can see how they would liketo be able to use the grace measurement along with a model to derive water on the land but surely those grace measurements will be significantly influenced by atmospheric water too?
Thank God for the Internet and Anthony Watts, Joanne Nova and Tory Aardvark, and others.
Most of us unless we read a lot would not be alerted or know about the various climatic conditions and the cause and effect factors. One thing I learned at University when studying a unit in humanities called ‘Earth In Crisis?’ in 2003 was that we are in an Interglacial but can expect one day in the not too distant future we will get colder. We are an ice planet. Spending more eons frozen than in Interglacials. Also the Northern Hemisphere experienced more severe glacial periods than the Southern Hemisphere. What we have to respect is with increasing populations we have to feed them. And the globe gets warmer (more rain) it is beneficial for crops and animal husbandry. If it gets colder this will not be so good for agriculture and we will have to adapt.
May be one of you can explain to me and if this has some truth. The Gulf Stream when it slows
does contribute to a glacial period. Melting glaciers flood the region and the fresh water pushes the warmer water down deeper. However, the Panama canal has been built and this allows some current to flow not like before between the Pacific and the Atlantic to stimulate the Gulf Stream functioning therefore maybe any more mini or full glacial periods might be moderated or less harmful to the Northern Atlantic countries. Australia didn’t suffer to badly last time the only glacial areas were high up in the Alps and also in parts of Tasmania. So ADAPT you stupid humans.
But don’t add oil to the fire by introducing toxic carbon trading a rouse and proving disasterous to countries engaged in this. You get these so called AGW scientist trying to prove by seeing a lump of sea ice break off this means global warming. It happens all the time as if you remember at school, the Arctic is not a continent or rather the North Pole isn’t unlike Antarctica. Only the Arctic circle has Green land and also Iceland that have a land base. Do you know, and Scottish
Skeptic will agree the Hebrides and some Northern Scottish Islands have a land of the Midnight sun like Norway. How can you put the same rules to this region as one does to say Australia or the Equator. I wonder if solar panels would work there eh? LOL
The Washington Post is carrry the story today, BUT they open the article with:
“The global sea level this summer is a quarter of an inch lower than last summer, according to NASA scientists, in sharp contrast to the gradual rise the ocean has experienced in recent years.”
http://www.washingtonpost.com/national/health-science/weather-cycles-cause-a-drop-in-global-sea-level-scientists-find/2011/08/25/gIQA6IeaeJ_story.html
Gee, I guess sea level has only been rising for a few years.
My question is if this 6 mm drop already included the 3.2 mm adjustment for the ocean floor subsiding. Is this post adjustment and really a 9.2 mm drop?
…there’s a hole in the bucket, dear Liza, dear Liza…
“If you mix 9 parts 0C with 1 part 30C you get a smaller volume of 3C. If wonder if climate scientist are aware of this?”
No, they are not very wise and educated in hard science otherwise they will not be climate ‘scientist’ (a.k.a. warmist hysteric)
The NASA PR guy hit a pothole of his own. The sea level has been rising since around 22,000 years ago and tailing off for centuries. The minuscule current rise is part of a mathematical trend to zero, and that’s been measured by floats and similar methods directly for over a century by coastguards and the like. Such a trend, even if it had been begun from scratch by CO2 warming, is so small as to be statistically irrelevant, much as a 0.8C rise in temperature over 150 years. Whichever way they have it, all of the danger they speak of hasn’t actually happened, they don’t claim it has, and expect (quite successfully) enough bloody idiots to accept their ‘models’ (much as Nostrodamus or Harold Camping used) which believe and claim to predict the long term future in an open and chaotic non-linear system. You can fool some of the people some of the time but the weight of contrary evidence in the last few years is gradually becoming noticed by the average followers of authority and wondering why the two are different. This divergence is almost guaranteed to continue until there’s nothing left to support any of their claims.
The Antarctic is getting colder, the ice there is growing. That mops up enough to guarantee a stable or falling sea level if continues, and neither ice nor sea can move in the opposite direction in response to warming. None of the 1990s predictions expected a reversal of any of the warming related phenomena, yet one by one they’ve happened and excuses are generated at a frightening speed to explain every single one away, including two of the coldest winters in living memory in the UK, the exact year the IPCC said snow would become a memory in the UK by 2010. That and the Himalayan glaciers are typical examples of how some newly rich and successful obscure researcher in the backwoods becomes a media star by using Mann’s method of keeping the message clear and not allowing any possible doubts. They got paid already, they don’t care if they were right or wrong as nearly every prediction is forgotten a year on when it doesn’t happen. They all know that so can say anything they like as if it fits the rules then it gets used.
Until the public get the point and stop voting for parties who claim to believe this nonsense nothing will ever change. Even if people start realising it’s junk they still won’t realise if they vote for most major parties they all have the same green policies so must learn exactly who’s going to support what and then vote for the others. Trust me, whatever else happens if the majority of the civilised world goes green it’ll be a depression like we’ve never seen before. No other policies will matter if all the wealth is stolen for windmills and solar panels and fuel costs so much half the poor will get hypothermia. Power rationing was planned in the Stern Report as was in recent Australian policies. Between the taxes, price hikes and energy and travel restrictions the western economy will be wrung dry while the third world will take over.
Really? Rainfall in Louisiana is down this year? I don’t think so. It is Texas that is dry, not Louisiana. They better check their master map again.