Posted on 04/22/2008 11:32:05 AM PDT by cogitator
PASADENA, Calif. -- Boosted by the influence of a larger climate event in the Pacific, one of the strongest La Ninas in many years is slowly weakening but continues to blanket the Pacific Ocean near the equator, as shown by new sea-level height data collected by the U.S.-French Jason oceanographic satellite.
This La Nina, which has persisted for the past year, is indicated by the blue area in the center of the image along the equator. Blue indicates lower than normal sea level (cold water). The data were gathered in early April.
The image also shows that this La Nina is occurring within the context of a larger climate event, the early stages of a cool phase of the basin-wide Pacific Decadal Oscillation. The Pacific Decadal Oscillation is a long-term fluctuation of the Pacific Ocean that waxes and wanes between cool and warm phases approximately every five to 20 years. In the cool phase, higher than normal sea-surface heights caused by warm water form a horseshoe pattern that connects the north, west and southern Pacific, with cool water in the middle. During most of the 1980s and 1990s, the Pacific was locked in the oscillation's warm phase, during which these warm and cool regions are reversed. For an explanation of the Pacific Decadal Oscillation and its present state, see: http://jisao.washington.edu/pdo/ and http://www.esr.org/pdo_index.html .
A La Nina is essentially the opposite of an El Nino. During El Nino, trade winds weaken and warm water occupies the entire tropical Pacific Ocean. Heavy rains tied to the warm water move into the central Pacific Ocean and cause drought in Indonesia and Australia while altering the path of the atmospheric jet stream over North and South America. During La Nina, trade winds are stronger than normal. Cold water that usually sits along the coast of South America is pushed to the middle of the equatorial Pacific. A La Nina changes global weather patterns and is associated with less moisture in the air, and less rain along the coasts of North and South America.
"This multi-year Pacific Decadal Oscillation 'cool' trend can intensify La Nina or diminish El Nino impacts around the Pacific basin," said Bill Patzert, an oceanographer and climatologist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The persistence of this large-scale pattern tells us there is much more than an isolated La Nina occurring in the Pacific Ocean."
Sea surface temperature satellite data from the National Oceanic and Atmospheric Administration also clearly show a cool Pacific Decadal Oscillation pattern, as seen at: http://www.cdc.noaa.gov/map/images/sst/sst.anom.gif .
The shift in the Pacific Decadal Oscillation, with its widespread Pacific Ocean temperature changes, will have significant implications for global climate. It can affect Pacific and Atlantic hurricane activity, droughts and flooding around the Pacific basin, marine ecosystems and global land temperature patterns.
"The comings and goings of El Nino, La Nina and the Pacific Decadal Oscillation are part of a longer, ongoing change in global climate," said Josh Willis, a JPL oceanographer and climate scientist. Sea level rise and global warming due to increases in greenhouse gases can be strongly affected by large natural climate phenomenon such as the Pacific Decadal Oscillation and the El Nino-Southern Oscillation. "In fact," said Willis, "these natural climate phenomena can sometimes hide global warming caused by human activities. Or they can have the opposite effect of accentuating it."
Jason's follow-on mission, the Ocean Surface Topography Mission/Jason-2, is scheduled for launch this June and will extend to two decades the continuous data record of sea surface heights begun by Topex/Poseidon in 1992. JPL manages the U.S. portion of the Jason mission for NASA's Science Mission Directorate, Washington, D.C.
For more information on NASA's ocean surface topography missions, see: http://sealevel.jpl.nasa.gov/ ; or to view the latest Jason data, visit: http://sealevel.jpl.nasa.gov/science/jason1-quick-look/ .
so much for the 2008 Atlantic hurricane season
If you give a fudge factor a technical name, is it still a fudge factor?
If you don’t understand the primary influence on a system, do you really understand the system?
Aaaah yes, the obligatory CYA.
I find it telling that the last time the pacific was in its “cool phase” corresponded almost exactly to the time when scientists worldwide were warning of a new ice age, and winters were especially strong. Then, all through the 80s and into the 90s, temps warmed, just in time for scientists worldwide to yammer about a coming “global warming” heatwave.
Now we’ve just had a particularly strong winter, which still lingers in the north, and the pacific is cooling again. Global temps have stayed static or even declined over the past several years.
From 2001....We wonder why the Arctic Sea ice waxes and wanes? Must be global warming>? Nah, more likely the shifting currents of the Pacific Ocean. But you say, the sea ice is at record low. Nah, has pretty much returned to ‘normal’ extent. But, but, it was lowest on record last summer, it will be totally gone in 20-30 years. Nah, the ‘records’ only go back to 1978, when the first sat to take daily pictures of Arcitc was sent up. Today, April 22, 2008, we have much more sea ice in Arctic than April 22, 2007.
Like fall and winter of 2000, this year’s (2001) TOPEX/Poseidon satellite data shows that the Pacific Ocean continues to be dominated by the strong Pacific Decadal Oscillation, which is larger than the El Niño/La Niña pattern. The data, taken during a ten-day collection cycle ending Oct. 29, 2001, show that the near-equatorial ocean has been very quiet in the past year, and sea levels and sea surface temperatures are near normal. Above-normal sea surface heights and warmer ocean temperatures, indicated by the red and white areas, still blanket the far western tropical Pacific and much of the north mid-Pacific.
The cool phase of the PDO could potentially exert a cooling influence on the climate. But the difference between now and the 1970s is twofold; higher atmospheric CO2 concentrations and lower SO2 aerosol pollution (though the Chinese are doing their best to counteract that). It’ll be interesting to see what happens next.
Sea ice records go a lot further back than 1978.
Given the relatively cool Northern Hemisphere winter, there has been a good freeze of the Arctic Ocean, but it's mostly first-year ice. I'll be curious to see how much the Arctic sea ice melts this summer.
Not sat data...the other data was gathered by ships and coastal observations and thus is like comparing apples to oranges.
I’m just Hoping we have summer. I want Change.
Come on, cogitator... you know damned well that those are reconstructions.
Plus, I note you’re cherry picking... How come you didn’t post that same site’s more recent, detailed record... the one showing the remarkable rebound in sea ice?
Then there’s that little matter of the Antarctic sea ice shattering the old records...
I am aware that the data is not satellite data; but going back to the 1950s at least, ice extent was estimated by aerial survey. Going back further than that, ship and coastal surveys provide the data. How would you argue that such observations are so flawed that they do not provide a reasonably accurate indication of sea ice extent?
I offer the following references for your examination. If you have problems with the methodologies, explain what they are.
Global Warming and Northern Hemisphere Sea Ice Extent
The key reference is 13, by Chapman and Walsh. Here's their Web site:
Arctic Climate Research at the University of Illinois
The data is online and Dr. Chapman invites anyone with questions about it to contact him by email. Why don't you email him and discuss how the data quality of the observational archive compares with the more recent satellite data?
Here is the documentation page for the sea ice data. I recommend reading the "Expert User Guidance" section:
Walsh and Chapman Northern Hemisphere Sea Ice Data Set
dangus, there are a couple of nice papers out there reporting that increased Antarctic sea ice is a consequence of global warming. I've posted the links to them before and I'm a tad lazy today. Google works to find them.
Try an example: The warmest year in recent history was 1934. 1931, 1938 and 1939 were in the top ten. However this cannot be discerned in the ground-based ice extent observations shown in your chart. 1953, the seventh warmest year...had the greatest sea ice extent, according to your chart!
Either the chart is flawed, or its association with average temperatures is flawed.
Only in the United States. I assume that the rest of your dates are for the U.S., and not the global values?
Anyway, sea ice is influenced by more factors than temperature, though temperature is important. And the values look pretty constant, so it would be hard to discern an overriding temperature influence, I would think.
Who’s Nina Linger?
Looks like we are still coming out of the Little Ice Age.
Ok, 1945 was a particularily warm year by global standards.
And 1957 was an espscially cool year.
Yet your graph shows no change.
And by your own admission, sea ice is not a good indicator of average atmospheric temperature.
The key factor is the number of melting days.
I wasn't aware I had done that; perhaps I stated something poorly.
Here are some of those "observations":
The Arctic ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot.... Reports from fishermen, seal hunters and explorers, he declared, all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone... Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared. Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts, which have never before ventured so far north, are being encountered in the old seal fishing grounds. - Washington Post 11/2/1922 (This observation does not appear in your chart)
The United States and the Soviet Union are mounting large-scale investigations to determine why the Arctic climate is becoming more frigid, why parts of the Arctic sea ice have recently become ominously thicker and whether the extent of that ice cover contributes to the onset of ice ages. – New York Times - July 18, 1970 (This observation contradicts your chart)
The Oceanographic observations have, however, been even more interesting. Ice conditions were exceptional. In fact, so little ice has never been noted. The expedition all but established a record….Journal of the Royal Meteorological Society - January 1905 (This observation does not manifest itself in your chart)
Scientist says Arctic ice will wipe out Canada, Professor Gregory of Yale University stated that “another world ice-epoch is due.” He was the American representative to the Pan-Pacific Science Congress and warned that North America would disappear as far south as the Great Lakes, and huge parts of Asia and Europe would be “wiped out.” – Chicago Tribune August 9, 1923 (This observation does not manifest itself in your chart)
See post 12.
Quote from page 3:
"When compared to longer- term, ground-based surface temperature data, the rate of warming in the Arctic from 1981 to 2001 is eight times larger than the rate of Arctic warming over the last 100 years. There have also been some remarkable seasonal changes. Arctic spring, summer, and autumn have each warmed, lengthening the seasons when sea ice melts by 10 to 17 days per decade. Temperatures increased on average by almost one and a quarter (1.22) degrees Celsius (C) per decade over sea ice in the Arctic summer."
I thought this was a pretty cool and informative article at first.
But this killed it for me:
>>Sea level rise and global warming due to increases in greenhouse gases can be strongly affected by large natural climate phenomenon such as the Pacific Decadal Oscillation and the El Nino-Southern Oscillation. “In fact,” said Willis, “these natural climate phenomena can sometimes hide global warming caused by human activities. Or they can have the opposite effect of accentuating it.”<<
It exposed the agenda.
Actually, up to that paragraph it IS a pretty informative article. Like so many articles by Global Warming and TOE True Believers, it is not the facts in the articles with which I have a problem. It is with the conclusions they make. Whenever I see the word “may” in an article, I always internally add the words “or may not”.
Examples:
Willis Tries to Dismiss His Own Ocean Non-Warming Research
Josh Willis Comments On Ocean Heat Content Trends
So it seems to me that skeptics don't like it when a good, careful, conscientious and cautious scientist tries to explain why the data doesn't fit their preconceived notions about what's important and what it's supposed to be doing.
(I find it interesting that a skeptic who doesn't apparently specialize in oceanography is telling an oceanographer what his observations mean.)
Looks like there is a lot of politics involved. Which again would explain the paragraph I quoted.
Regarding a “non-specialist” questioning a “specialist”. It is actually what I do for a living. Even rocket science aint rocket science. A relatively intelligent lay-person with a teachable mind can often question experts in such a way that even though the questioner doesn’t fully understand the nuances of the subject, they can get an expert to see their area different and begin to question their own conclusions.
This is especially effective when dealing with just a small microcosm of the knowledge base on which the expert normally calls to to their job.
FOr a silly example, it happened to the automotive “expert” in My Cousin Vinny.
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