Posted on 11/14/2002 3:41:16 PM PST by blam
Source: Syracuse University
Date: 11/14/2002
New Evidence That El Niño Influences Global Climate Conditions On A 2,000-Year Cycle
El Niño, the pattern that can wreak havoc on climate conditions around the world, is like a beacon, pulsating through time on a 2,000 year cycle, according to a new study by scientists from Syracuse University, Syracuse, N.Y.; Union College, Schenectady, N.Y., and from the NOAA Paleoclimatology Program, Boulder, Colo., that is being published in the Nov. 14 issue of Nature. The study, which resulted from a detailed analysis of a continuous 10,000-year record of El Niño events from a lake in southern Ecuador, is the first documented evidence that such a millennial cycle exists for El Niño. The researchers found that the frequency of El Niño events peaked about 1,200 years ago, or during the early Middle Ages. If the pattern continues into the future, there should be an increase in El Niño events in the early part of the 22nd century, the scientists say.
"El Niño operates within its own kind of 2,000-year rhythm, and because of that, we believe these periodic changes have had a major impact on global climate conditions over the past 10,000 years," says Christopher Moy G'00, the lead author of the study and a 2000 graduate of Syracuse University. "El Niño is one of the primary forces that can alter climate around the globe during a short period of time."
The study is the result of work Moy did as a graduate student in the Department of Earth Sciences in Syracuse University's College of Arts and Sciences for his master's thesis. His advisor was Prof. Geoffrey Seltzer. In a 1999 study published in Science, Seltzer and Donald T. Rodbell, who was Moy's undergraduate advisor at Union College, discovered the first continuous record of El Niño events that dated back more than 5,000 years. That study was based on sediment samples taken in 1993 from the same lake in southern Ecuador--Lake Pallcacocha--as part of a larger global climate study on which they were collaborating.
This new study of El Niño events is based on another set of sediment cores taken in 1999 from Lake Pallcacocha, which is located in the Andes Mountains. The National Science Foundation funded the research.
Characterized by warm sea surface temperatures that appear off the western coast of South America, modern El Niño events cause dramatic changes in the weather systems across both the North and South American continents--from tumultuous rainfall in northern Peru and southern Ecuador to unusually warm and dry conditions in the northeastern United States.
Like the 1993 sediment core samples, the new core samples contain a series of light-colored sediment layers that contain the type of debris that would flow into the lake during periods of intense precipitation. In his analysis of the sediment layers, Moy confirmed results from the first study--that scattered El Niño events began about 10,000 years ago and steadily increased in frequency beginning about 7,000 years ago. In addition to that, he uncovered high-frequency clusters of El Niño events occurring on a 2,000-year cycle.
"About every 2,000 years, we see a lot of El Niño activity," says Moy, who is currently a graduate student at Stanford University and plans to pursue a Ph.D. in geology and environmental science. "This oscillation has not been seen in any other study of climate records of this area of the world, which makes this study unique. El Niño is an important part of our modern-day climate system. Likewise, our study shows it was also an important part of the earth's climate system 7,000 years ago. Understanding the past will help us to better understand future climate changes."
Seltzer says that Moy's study sheds new light on a tropical phenomenon that can radically alter climate conditions in a relatively short period of time. "We are extremely excited and pleased that the research Chris did as a Syracuse University graduate student is now being published in a premier, international journal and that he is moving toward greater accomplishments in the field. It's the ultimate outcome for our program and of a student-centered research university like Syracuse University."
--------------------------------------------------------------------------------
Note: This story has been adapted from a news release issued for journalists and other members of the public. If you wish to quote any part of this story, please credit Syracuse University as the original source. You may also wish to include the following link in any citation:
http://www.sciencedaily.com/releases/2002/11/021114072253.htm
Does that mean we have a 2,000 year 'dry-spell' coming?
In the period between A.D. 1125 and 1180, very little rain fell in the region. After 1180, rainfall briefly returned to normal. From 1270 to 1274 there was another long drought, followed by another period of normal rainfall. In 1275, yet another drought began. This one lasted 14 years.
The Peruvians continued building the complexes for nearly 3,000 years. But evidence indicates that around 2800 B.C., the sites were abandoned. Scientists working in Peru think they know why. . . . "We found that there was a change in the frequency of El Niño events about 3,000 years ago and that this correlates in time with cultural change," said Daniel Sandweiss, an archeologist.
In recent times El Niño has happened every two to seven years. Until the last quarter of this century, it occurred every seven to fifteen years.
This research is only part way to the answer.
| To find all articles tagged or indexed using Global Warming Hoax , click below: | ||||
| click here >>> | Global Warming Hoax | <<< click here | ||
| (To view all FR Bump Lists, click here) | ||||
El Nino (when I was younger it was the Equatorial Countercurrent) is but one element in a combination of oscillatory phenomenae. We have the 11 year sunspot cycle. We have the Pacific Decadal Oscillation (a cyclical north/south temperature inversion pattern). We have century long solar cycles and of course volcanic and astrological singularities.
It's complex. We could study it forever and still not know it all. Good. Sounds like God's gift of a world to me. Who'd ever want the learning to end?
So, what we don't do is to develop established habitat management processes with which to respond to an array of unpredictable contingencies weighted by ojectively assessed risk and statistical probability. No, what we've got is a single-point plan dictated by a nascent global bureaucracy to benefit corrupt political interests chasing a passel of bought off computer models in service to a bogus premise.
Yeah, that'll work. Nothing quite like elite leadership.
Uh, Mr. Rockefeller, doncha think you might want to rethink that?
Nothing so malevolant. The current is produced by coriolis forces and gravity. The two Pacific current cycles (gyres) circulate in opposite rotational directions but flow together west to east along the equator. That piles up so much warm water in the Eastern Pacific (because it just came across the equator) it piles up with nowhere to go until it wants to flow back east toward South America. Warm water is less dense, so it floats on top of the west to east flow. It varies in intensity from year to year because the water pile has to build until it unloads along with relative temperature differences adding to or working against the fluid friction.
That's El Nino. It's really pretty simple in principle, but predicting its behavior isn't.
Foundation of Holy Roman Empire.
Islam driven back.
Iceland founded.
Medieval Maximum period of climate.
American Great Planes farming.
The El Nino current is produced by coriolis forces and gravity. The two Pacific current cycles (gyres) circulate in opposite rotational directions but flow together EAST to WEST along the equator (brain was thinking Far East... I know, tired). That pushes so much warm water (because it just came across the equator) toward the WESTERN Pacific that it piles up against the coast of Australia, Indonesia, and Indochina with nowhere to go. The pile then starts to flow backward on top of the two confluent gyre currents back toward South America along the equator. The reason the El Nino stays confined in a narrow path along the equator is that coriolis forces pile water in toward the centers of the two gyres. "Sea level" at the center of the gyres is about 4 meters higher than average, creating a "trough" along the equator to channel the El Nino. Warm water is less dense, so the El Nino flows in the trough WEST to EAST on top of the east to west gyre currents until it hits South America, sheets out, and dissipates.
El Nino varies in intensity from year to year because the water pile has to build until it unloads along with relative temperature differences adding to or working against the fluid friction and seasonally variable winds.
Next time I'll draw myself a picture when I explain it instead of working from memory. Sheesh.
During an El Nino, the winds blow toward the east and 'pile-up' warm water along the coast of South America (affecting the Humboldt Current too).
I think my question is, if there was a large opening through N/S America, would this warn water surge through there...and what would be the consequences?
My interest in such things are primarly related to humans and human civilizations. If there hasn't been an opening there for 50 million years, then, I'm little interested. I like to try to connect catastrophic events to the rise and fall of ancient civilizations. BTW, I'm a chip-maker (retired) by trade and started my career in the mid-60's right there in your 'back yard'. (All this weather/climate stuff is Greek to me.)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.