Global sea level rise dampened by Australia floods

Aug 19, 2013
Heavy rains transformed Australia's landscape, as show in these two NASA satellite images of floodplains in southwestern Queensland. The first image was taken on September 26, 2009. By the time of the second image, on March 26, 2011, so much rain had been driven over Australia instead of falling on the ocean that global sea levels temporarily dropped. (Image taken with the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite.) Credit: LANCE MODIS Rapid Response.

When enough raindrops fall over land instead of the ocean, they begin to add up. New research led by the National Center for Atmospheric Research (NCAR) shows that when three atmospheric patterns came together over the Indian and Pacific oceans, they drove so much precipitation over Australia in 2010 and 2011 that the world's ocean levels dropped measurably. Unlike other continents, the soils and topography of Australia prevent almost all of its precipitation from running off into the ocean.

The 2010-11 event temporarily halted a long-term trend of caused by higher temperatures and sheets.

Now that the atmospheric patterns have snapped back and more rain is falling over tropical oceans, the seas are rising again. In fact, with Australia in a major drought, they are rising faster than before.

"It's a beautiful illustration of how complicated our climate system is," says NCAR scientist John Fasullo, the lead author of the study. "The smallest continent in the world can affect sea level worldwide. Its influence is so strong that it can temporarily overcome the background trend of rising sea levels that we see with ."

The study, with co-authors from NASA's Jet Propulsion Laboratory and the University of Colorado at Boulder, will be published next month in Geophysical Research Letters. It was funded by the National Science Foundation, which is NCAR's sponsor, and by NASA.

Consistent rising, interrupted

As the climate warms, the world's oceans have been rising in recent decades by just more than 3 millimeters (0.1 inches) annually. This is partly because the heat causes water to expand, and partly because runoff from retreating glaciers and ice sheets is making its way into the oceans.

But for an 18-month period beginning in 2010, the oceans mysteriously dropped by about 7 millimeters (about 0.3 inches), more than offsetting the annual rise.

Fasullo and his co-authors published research last year demonstrating that the reason had to do with the increased rainfall over tropical continents. They also showed that the drop coincided with the atmospheric oscillation known as La Niña, which cooled tropical surface waters in the eastern Pacific and suppressed rainfall there while enhancing it over portions of the tropical Pacific, Africa, South America, and Australia.

But an analysis of the historical record showed that past La Niña events only rarely accompanied such a pronounced drop in sea level.

Using a combination of satellite instruments and other tools, the new study finds that the picture in 2010 was uniquely complex. A rare combination of two other semi-cyclic climate modes came together to drive such large amounts of rain over Australia that the continent, on average, received almost one foot (300 millimeters) of rain more than average.

The initial effects of La Niña were to cool surface waters in the eastern Pacific Ocean and push moisture to the west. A climate pattern known as the Southern Annular Mode then coaxed the moisture into Australia's interior, causing widespread flooding across the continent. Later in the event, high levels of moisture from the Indian Ocean driven by the Indian Ocean Dipole collided with La Niña-borne moisture in the Pacific and pushed even more moisture into the continent's interior. Together, these influences spurred one of the wettest periods in Australia's recorded history.

Australia's vast interior, called the Outback, is ringed by coastal mountains and often quite dry. Because of the low-lying nature of the continent's eastern interior and the lack of river runoff in its western dry environment, most of the heavy rainfall of 2010 remained inland rather than flowing into the oceans. While some of it evaporated in the desert sun, much of it sank into the dry, granular soil of the Western Plateau or filled the Lake Eyre basin in the east.

"No other continent has this combination of atmospheric set-up and topography," Fasullo says. "Only in Australia could the atmosphere carry such heavy tropical rains to such a large area, only to have those rains fail to make their way to the ocean."

Measuring the difference

To conduct the research, the scientists turned to three cutting-edge observing instrument systems:

  • NASA's Gravity Recovery and Climate Experiment (GRACE) satellites, which make detailed measurements of Earth's gravity field. The satellites enable scientists to monitor changes in the mass of continents.
  • The Argo global array of 3,000 free-drifting floats that measure the temperature and salinity of the upper 6,000 feet of the world's oceans.
  • Satellite-based altimeters that are continuously calibrated against a network of tide gauges. Scientists subtract seasonal and other variations to closely estimate global sea level changes.

Using these instruments, the researchers found that the mass in Australia and, to a lesser extent, South America began to increase in 2010 as the continents experienced heavy and persistent rain. At the same time, sea levels began to measurably drop.

Since 2011, when the atmospheric patterns shifted out of their unusual combination, sea levels have been rising at a faster pace of about 10 millimeters (0.4 inches) per year.

Scientists are uncertain how often the three atmospheric events come together to cause such heavy rains over Australia. Fasullo believes there may have been a similar event in 1973-74, which was another time of record flooding in that continent. But modern observing instruments did not exist then, making it impossible to determine what took place in the atmosphere and whether it affected sea level rise.

"Luckily we've got great observations now," Fasullo says. "We need to maintain these observing platforms to understand what is a complicated ."

Explore further: NASA HS3 mission Global Hawk's bullseye in Hurricane Edouard

More information: Australia's unique influence on global sea level in 2010, John T. Fasullo, Carmen Boening, Felix W. Landerer, R. Steven Nerem, Geophysical Research Letters

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User comments : 17

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Kiwini
1.8 / 5 (19) Aug 19, 2013
"Global sea level rise dampened by Australia floods".... is that a weak attempt at a pun, or is it the usual confusion about that word being wrongly substituted for damping, ie: reducing in intensity.
NikFromNYC
2.2 / 5 (24) Aug 19, 2013
"when three atmospheric patterns came together over the Indian and Pacific oceans, they drove so much precipitation over Australia in 2010 and 2011 that the world's ocean levels dropped measurably."

Indeed, this is strikingly seen in satellite data:
http://ibis.grdl....ries.php

What is not seen is any upswing in trend. Instead, it has become standard operating procedure for the press offices of NASA and other four letter agencies to cut tide gauge data off (apples) and next to it plot satellite data (oranges) and then spout mealy-mouthed propaganda about apples turning into oranges, er I mean sea level suddenly jumping in trend:
http://s22.postim..._Two.jpg

Such behavior toppled the Copenhagen Accord of December 2009, after the November 2009 "Climategate" release of Hockey Stick Team "Hide The Decline" e-mails which involved similar data deletion (the decline of crucial tree ring widths as recent temperature kept rising).
runrig
3.2 / 5 (11) Aug 19, 2013
Such behavior toppled the Copenhagen Accord of December 2009, after the November 2009 "Climategate" release of Hockey Stick Team "Hide The Decline" e-mails which involved similar data deletion (the decline of crucial tree ring widths as recent temperature kept rising).


Those of an open mind might wish to view this:
http://www.youtub...Ve6KE-Us
Which while debunking the above also has the happy adjunct of addressing the once anti-AGW crowds favourite son Dr R Muller's conversion to believer.

Oh - and I feel this has a lot to say about certain opinions expressed on here.
http://www.earthm...carolina
NikFromNYC
2.1 / 5 (21) Aug 19, 2013
runrig's very article is slanderously headlined: "Denying sea-level rise."

Who the hell looks at a graph of steadily rising sea level and "denies" it?!

Amateur hour "Climate Communicator" Gorebots infest sites like this after huddling in a private forum where they recently planed to promote a confirmation of the 97% consensus claim *prior* to crunching the data. That's fraud.

A similar example is from the above study, which mentions "The Argo global array of 3,000 free-drifting floats...."

When the data showed significant cooling, they corrected it to only slight cooling back to 2004 and part of 2003. But the statistically significant *lack* of warming required a smoke screen, so out came the Gorebot$, screaming about how the mild *cooling* wasn't statistically significant and spread claims that serious skeptics willfully misunderstand statistics, all based on a few newbie skeptics pointing to the damn Argo data plots that indeed showed "cooling" based on random endpoint cutoffs.
NikFromNYC
2 / 5 (20) Aug 19, 2013
runrig's article digs deeper in total mindfuck fashion: "However, just below the surface, there is another America. This America is populated by people who — on economic, political or religious grounds — have chosen to reject the consensus of the global scientific community on various topics."

The study by runrig's buddy, the evangelical Christian comic pane artist John Cook, which was plugged in Obama's Twitter feed that supported the 97% consensus claim (the original of which the vast majority of skeptics would be counted within since it only asked if recent warming was enhanced by CO₂ and *not* if they agreed that CO₂ represented any danger instead of benefit) turned out to be utterly bogus:

http://www.popula...sts.html

Their entire result pivots the other way if you correct their use of the boutique search term "global climate change" and substitute the legitimate term "climate change."
NikFromNYC
1.8 / 5 (19) Aug 19, 2013
runrig wrote: "... the once anti-AGW crowds favourite son Dr R Muller's conversion to believer."

"Former skeptic" Muller in 2008: "Back in the early '80s, I resigned from the Sierra Club over the issue of global warming. At that time, they were opposing nuclear power. What I wrote them in my letter of resignation was that, if you oppose nuclear power, the U.S. will become much more heavily dependent on fossil fuels, and that this is a pollutant to the atmosphere that is very likely to lead to global warming."

And in 2011: "I never felt that pointing out mistakes qualified me to be called a climate skeptic."

Dr. Muller of Berkeley created a new global average temperature plot by the innovation of automatically snipping each thermometer station's data into *pieces* whenever there was a jump. It resulted in a hockey stick that was extended back to 1800 instead of the usual 1880, but the few stations that go back that far destroy it:

http://s24.postim...nous.gif
runrig
3.2 / 5 (11) Aug 19, 2013
The study by runrig's buddy, the evangelical Christian comic pane artist John Cook,

Don't judge me by your standards.
I did no research on who made the video. It simply tells the truth about a self-fulfilling prophecy believed only by deniers.
Do try to realise that there are people who understand the science. You know? the people who taught you your Phd?

Oh BTW don't bother with the character assassination drivel. I'm a scientist ( practical and now retired ). My eyes just glaze over with your verbal diarrhea.

BTW again - the post was addresses to "people of an open mind".
NikFromNYC
2 / 5 (20) Aug 19, 2013
runrig sniped: "It simply tells the truth about a self-fulfilling prophecy believed only by deniers."

The terms "truth," "belief," and "denier" are all you need to state for the record to demonstrate that you promote religious instead of scientific ideals.

Do you want to know what my old chemistry professors think about junk science environmentalism?! They don't speak out since they don't even consider climatology a science, but more a branch of politics or at best a goofy thing like sociology. But if they did speak out, it would be the kiss of death of their career, would it not? There's a reason skeptics tend to be of retirement age. That reason is you, runrig, and your Greenpeace buddies, you know, the ones who crushed the low emissions Atomic Age in the first place and also send funds to the eco-terrorist group Earth First?

Whose standard should I judge you by if not my own? Pinocchio's?
runrig
4.1 / 5 (9) Aug 19, 2013
Whose standard should I judge you by if not my own? Pinocchio's?

If you want to - that would be closer to the truth. Your nose is indeed getting longer in my eyes.
You think you can address me as some intellectual inferior who arrives at his beliefs as you do by deciding that something is wrong and then Googling for the evidence of same - except you exhibit a unique talent at being inordinately pleased with your efforts. As though that and verbal diarrhea/repetition makes you correct and gives you by default the upper hand. Childish.
Go back to your professors and tell them that all they taught you was wrong. You plainly have the self-regard to.
You can teach me nothing about Meteorology - just as I can teach you nothing about chemistry. The difference between the two of us is that I know that ( hence the standards ). Stop being a hypocrite and just resort to calling me an asshole again if it makes you feel better.
Shootist
1.7 / 5 (17) Aug 19, 2013
Global sea level rise dampened by Australia floods


Oh, my aching algore.
rug
2.1 / 5 (7) Aug 19, 2013
Stop being a hypocrite and just resort to calling me an asshole again if it makes you feel better.


Hey asshole, you're right. lol Sorry, couldn't resist.
antigoracle
1.7 / 5 (17) Aug 19, 2013
Alrighty then. Australia the sponge of the world.
How convenient for the AGW Alarmist propaganda machinery.
runrig
4.3 / 5 (6) Aug 20, 2013
Alrighty then. Australia the sponge of the world.
How convenient for the AGW Alarmist propaganda machinery.


Didn't you know?
The science escaped you?
Bless.

It's part of the "inconvenient truth".
SteveS
5 / 5 (4) Aug 20, 2013
Dr. Muller of Berkeley created a new global average temperature plot....


Not just Dr. Muller, all these people contributed.

http://berkeleyearth.org/team

SteveS
5 / 5 (3) Aug 20, 2013
Dr. Muller of Berkeley created a new global average temperature plot....


If you have issues with the statistical treatment of the data you should take them up with this person

http://berkeleyea...-wickham
runrig
4.2 / 5 (5) Aug 20, 2013
Not just Dr. Muller, all these people contributed.

http://berkeleyearth.org/team


Yes indeed - but it's rather more involved for him to Google through the full "team" of scientists and dig out the "dirt" that is required to feed his paranoia. And by so doing, prove himself correct - because we all know it's all a grand conspiracy - don't we? That and incompetent, grant-greedy scientists, who "don't know basic high school science".
antigoracle
1.3 / 5 (12) Aug 23, 2013
Not just Dr. Muller, all these people contributed.

http://berkeleyearth.org/team


Yes indeed - but it's rather more involved for him to Google through the full "team" of scientists and dig out the "dirt" that is required to feed his paranoia. And by so doing, prove himself correct - because we all know it's all a grand conspiracy - don't we? That and incompetent, grant-greedy scientists, who "don't know basic high school science".

http://www.dailym...gue.html