View Full Version : Scientists uncover deep ocean current near Antarctica
27th April 2010, 04:56
By David Fogarty, Climate Change Correspondent, Asia
Posted 2010/04/25 at 2:05 pm EDT
SINGAPORE, Apr. 25, 2010 (Reuters) — Scientists have discovered a fast-moving deep ocean current with the volume of 40 Amazon Rivers near Antarctica that will help researchers monitor the impacts of climate change on the world's oceans.
A team of Australian and Japanese scientists, in a study published in Sunday's issue of the journal Nature Geoscience, found that the current is a key part of a global ocean circulation pattern that helps control the planet's climate.
Scientists had previously detected evidence of the current but had no data on it.
"We didn't know if it was a significant part of the circulation or not and this shows clearly that it is," one of the authors, Steve Rintoul, told Reuters.
Rintoul, of the Antarctic Climate and Ecosystems Cooperative Research Center in Hobart, said it proved to be the fastest deep ocean current yet found, with an average speed of 20 cm (7.9 inches) a second. It was also found to carry more than 12 million cubic meters a second of very cold, salty water from Antarctica.
"At these depths, below three kilometers (two miles) from the surface, these are the strongest recorded speeds we've seen so far, which was really a surprise to us."
He said the current carries dense, oxygen-rich water that sinks near Antarctica to the deep ocean basins further north around the Kerguelen Plateau in the southern Indian Ocean and then branches out.
GLOBAL CONVEYOR BELT
The current forms part of a much larger network that spans the world's oceans, acting like a giant conveyor belt to distribute heat around the globe.
Oceans are also a major store of carbon dioxide, the main greenhouse gas that is emitted naturally and by mankind, mainly from burning fossil fuels.
For example, the Gulf Stream brings warm water to the North Atlantic, giving northern Europe a relatively mild climate. Failure of the current, which has occurred in the past, would plunge parts of Europe into a deep freeze, scientists say.
"The deep current along the Kerguelen Plateau is part of a global system of ocean currents called the overturning circulation, which determines how much heat and carbon the ocean can soak up," Rintoul said.
A key part of the circulation is the creation of large volumes of the very cold, salty water in several areas along coastal Antarctica that then sinks to the bottom and flows to other ocean basins.
The team deployed measuring devices anchored to the sea floor at depths of up to 4.5 km (3 miles) and recorded current speed, temperature and salinity for a two-year period.
"The continuous measurements provided by the moorings allow us, for the first time, to determine how much water the deep current carries to the north," Rintoul said.
He said a key issue for predicting climate was whether the overturning circulation was going to stay at its present strength or whether it was sensitive to changes as climate changes.
That meant further improving measurements of the speed and volume of the cold, salty water that is created around Antarctica.
(Editing by Clarence Fernandez)
original story here;
22nd May 2010, 09:40
Climate Change Hits the Oceans
By MICHAEL D. LEMONICK Michael D. Lemonick
When scientists say the planet is warming, they usually point to rising air temperatures as proof. That's reasonable enough, especially since the warmth of the air temperature affects us directly so we feel the change the scientists are measuring. But it's also misleading: while the lower atmosphere has been gradually warming over the past 50 years, it happens unevenly, rising sharply for a year or two or even ten, then flattening out. That stutterstep pattern is due to relatively short-lived effects on top of the general warming - an El Nino current in the Pacific making things warmer, for example, or a volcanic eruption like 1991's Mt. Pinatubo producing a cloud of dust that makes things cooler. Over time, these cancel out, but it can be tempting - though incorrect - to think a temporary flattening means global warming has stopped.
To get a measure of what's truly going on, scientists look to the oceans - slow to heat up, slow to cool down, and thus less prone to short-term variations. Indeed, says John Lyman an oceanographer at the University of Hawaii, "about 80 or 90 percent of the extra heat absorbed by the planet is absorbed into the oceans." That being the case, Lyman and several colleagues set about trying to see how the ocean's heat content has changed over the past couple of decades. The result, appearing in the current issue of Nature, will give little comfort to climate change deniers: the oceans have been warming inexorably since at least 1993, at a rate broadly consistent with what you'd expect from the buildup of greenhouse gases. (See a photo gallery of climate change in Europe.)
There are some uncertainties in the numbers - not surprising, since the new study is essentially a synthesis of earlier papers, done by different groups using different instruments and making different sorts of measurements. "There's a large amount of error in the data," admits co-author Josh Willis, of NASA's Jet Propulsion Laboratory, in Pasadena. "But the signal of global warming is abut six times larger than any uncertainties." In particular, the so-called "global cooling" climate skeptics claim has been going on since 1998 doesn't show up. "If you look at our data since 1998," says Lyman, "it's warmed significantly."
The curve does flatten somewhat in 2003 - but that may have to do with things going on in the deep ocean. The sensors involved in the latest research go down only to about 2,300 ft., roughly half the average depth of the world's oceans. The upper and lower ocean exchange heat just as the ocean and atmosphere do, and nobody really knows what's happening near the bottom. Less than two months ago, in fact, Kevin Trenberth and John Fasullo, both climatologists at the National Center for Atmospheric Research, in Boulder, Colorado, published a paper in Nature suggesting that some of the extra heat trapped by greenhouse gases has gone missing - and that it might well be hiding in the deep oceans. Part of the problem, Trenberth suggested, was the same sort of incomplete measurements and inconsistencies in data processing Willis and Lyman describe in their own study. (See a special on December 2009's COP15 Climate-Change Conference.)
Incomplete though the numbers are, however, the results seem reasonably robust - and they're corroborated by another, entirely different set of measurements. As the oceans warm, they expand; indeed, up to half of sea-level rise comes not from melting glaciers or disappearing ice caps, but from the physical expansion of seawater as it heats up. And like the ocean's heat content, the rise in sea level is gradual enough that over time, the year-to-year or even decade-long ups and downs disappear into a steady, long-term increase. "A century ago," says Willis, "sea level was rising at about one millimeter per year. Fifty years ago it was two. And now it's rising at three millimeters per year."
In short, the oceans are currently doing the heavy lifting in absorbing trapped heat. Ultimately, though, some of that heat will be transferred back to the air, continuing to warm the places we live even if we manage to stop generating greenhouse gases at such a great rate. That makes it crucial to understand exactly what's going on offshore. If scientists can refine their measurements, writes Trenberth in a commentary on this week's Nature paper, "ocean heat content is likely to become a key indicator of climate change." That key, in turn, may be one more tool to help slow the damage.
story linked here;
22nd May 2010, 11:45
Interesting that they find out these things, less interesting how they try to sow it into subtle attempts of evidence towards man made climate change.
I do indeed think there is something going on, it's wild out there, but is it our fault?
Wouldn't interfering with the said climate changes also be a man made climate change? Do we have nearly enough knowledge to be able to discern if our actions to stop the change won't just flip the coin and reverse the problem?
I highly agree that man has to change his ways, we can do things very differently, however, it is not our dear earth that needs saving from us. Climate change is a threat to our ways of living, it's a threat to our existence.
If anything, we are taking up the battle with nature...armed with propaganda, fear and deception....in order to preserve our way of life. In order to continue the massive meaningless consumption of every resource given to us.
As long as the fight for *our* so called right to be here on earth is going under a massive banner of global economy, there is no real reason to believe our ways will ever change.
The day I see these people, doing all this with only theirs and everyone elses lives as motivation, and not the abundant checks and payments...that's the day I personally think we've earned the right to be here.
We will live on, regardless of what happens...change is not to be feared...but we need to be wary of it and adjust accordingly.
It's time to stop building castles and fortresses just so we don't have to face our challenges....cause in the end, that's all we are trying to do.
22nd May 2010, 14:22
What I have to add to this thread topic, will sit easily with some and others will ridicule.
However, over the last few years, I have been reading about channeled messages from sources in other dimensions who state that the global warming phenomena is about 10% man-made and 90% due to natural cycles. There may also be a certain category of percentage that is due to a forced or purposeful man made global warming. When one considers the very power of the 20+ HAARP systems around the world that can be and are used as types of non-combat military operations, that 10% may very well be heavily elevated.
22nd May 2010, 23:16
Thanks~ Lucrum and Snowbird for your post and comments :yo:
You intuitive thoughts speak with much truth according to my research :yes4:
I have posted below a current overview pertaining to existing problems and trends that are threatening the world's oceans and coastal areas, that was written over 7 years ago (2003) and appears to be right on~ in regards to the current global situation by George Pararas-Carayannis who covered and wrote on the Johannesburg, South Africa~ Ocean Governance and Sustainable Development Conference in 2002
From his lecture Plenary Lecture - 30th Pacem in Maribus (PEACE IN THE OCEANS).
A Year after Johannesburg. Ocean Governance and Sustainable Development:
Ocean and Coasts - a Glimpse into the Future
Kiev, Ukraine, October 26-30, 2003
"Unequivocally, the world oceans, seas and coastal areas are presently in a state of crisis, facing a greater array of problems and dangers than ever before in the history of mankind. The population explosion in the latter part of the 20th Century has resulted in a growing urbanization of the world's coastal areas. There has been unprecedented commercial and residential over development along coastal areas - where more than half of the world's population now live. In many parts of the world this rapid expansion and development of mega cities has occurred along very vulnerable and fragile coastal zones that have unique ecosystems. Many of these mega cities are also exposed to numerous natural and man-made hazards. Climate changes, global warming and a rising sea level have complicated the problems.
In spite of the apparent vastness of the world's oceans, what once was considered inexhaustible and resilient has become, in fact, finite and fragile. The increasing pressure of excessive human use is straining marine life and vital coastal habitats. Toxic pollution from cities and fields, anthropogenic waste disposal, excessive nutrients and oil spills, increasingly threaten both living and nonliving resources in the coastal and oceanic environments - adversely impacting and fundamentally changing natural ecosystems and even threatening human health. Over fishing at sea, and increasing pollution are leading to a decline of ocean wildlife and to the collapse of many ecosystems.
The crossroad has now been reached where the cumulative effects of what is taken from and what is put into the world's oceans have reduced substantially the ability of marine ecosystems to produce the economic and ecological goods and services that are desired and needed. In brief, if present trends are allowed to continue and if there is continuing failure to responsibly manage the oceans and coastal regions, there is risk of much greater losses in the near future - at a much accelerated pace."
Also~ here's a very recent report by Michael Knight, Editor, Earth Change Report.
Massive Seabed Rise
If the earth is changing this much - we're in BIG trouble!
A guy who monitors the NOAA national data buoy center says the data shows that the sea floor is rising by as much as 13 feet A DAY in the Coral Sea.
Since the great tsunami of 2004 a chain of buoys has been tethered in various parts of the ocean to help act as a tsunami warning system. They tell scientists what's going on in terms of how high the ocean surface is above the sea floor. And it seems they have been feeding back some unexpected information.
As he says: "The National Oceanic and Atmospheric Administration has a Tsunami station in event mode activated for Station 55023 – STB Coral Sea located at 14.803 S 153.585 E (14°48’9″ S 153°35’6″ E).
"The tsunami station has been in event mode since the large quakes occurred in the area for several days now. This is triggered by the buoys’ anomalies of water column height above the sea floor. If you do a data search for 2010 March 20th to 2010 April 13th you get this- Over 100 meters or 328 feet less distance from buoy to sea floor in 24 days! That’s 13 feet per day since the quakes.
"This is disturbing."
If his analysis is accurate, it is disturbing indeed.
But if you go to the NOAA site, you'll find those buoys haven't been recording any data lately.
Suspicious, that. Are we being kept in the dark yet again? Quite likely. :eek:
you can subscribe to Michael Knight's New Earth News here;
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