[pct-l] No El Nino this year....
Gail Van Velzer
vanvelzer at charter.net
Tue Sep 30 19:07:18 CDT 2014
This is all very interesting. Did anyone hear of El Nino's before 1980?
----- Original Message -----
From: "Brick Robbins" <brick at brickrobbins.com>
To: "PCT" <pct-l at backcountry.net>
Sent: Tuesday, September 30, 2014 4:31 PM
Subject: [pct-l] No El Nino this year....
> California won’t see hoped-for relief from drought this winter,
> scientists say, because El Niño is likely to be weak or nonexistent.
> Earlier this year, many scientists anticipated a blockbuster 2014 El
> Niño that would rival the record-setting 1997 event. That year’s El
> Niño — a climate disruption generated by unusually warm seawater in
> the eastern Pacific Ocean — triggered severe weather worldwide,
> including storms and floods on the West Coast and droughts in
> Southeast Asia. But now the Climate Prediction Center of the National
> Oceanic and Atmospheric Administration projects that a strong El Niño
> is unlikely and the chances of even a mild one forming have dwindled
> to around 60 percent.
> A lack of wind gusts over the Pacific Ocean left this year’s El Niño
> dead in the water, researchers propose September 26 in Geophysical
> Research Letters. Scientists think these winds push warm seawater
> eastward, which in turn rises to the ocean surface along South
> America’s coast and heats the atmosphere, causing dramatic shifts in
> “If we had the same series of wind events in 2014 as we had in 1997,
> we would have gone strongly toward an El Niño state,” says study
> coauthor Jérôme Vialard, a climate scientist at the Laboratoire
> d'Océanographie et du Climate - Expérimentation et Approches
> Numériques in Paris.
> An oblong pool of warm seawater more than 14,000 kilometers wide
> always blankets the West Pacific. During the first few months of 1997
> and 2014, this warm pool shifted east as the westward trade winds
> The similarities between the two periods “set off an alarm within the
> community,” says study coauthor Christophe Menkes, a climate scientist
> at the Institute of Research for Development in New Caledonia, a
> self-governing French territory in the southwestern Pacific. The 1997
> El Niño killed an estimated 22,000 people and caused roughly $36
> billion in economic losses. However, in July 2014 unlike in 1997, the
> warm pool in the Pacific swung back to its normal position before
> rising to the ocean surface, decreasing the chance of a full-blown El
> Menkes believes El Niño conditions fell flat this year because wind
> gusts called antitrade winds stopped blowing in April. These eastward
> gusts, Menkes says, would have helped lock the warm pool in place
> after it shifted into the East Pacific.
> To determine whether the missing gusts were the key difference between
> the 1997 and 2014 seasons, Menkes, Vialard and colleagues did a
> virtual wind swap. Using computer simulations of the Pacific, the team
> calculated how 2014 El Niño conditions would have progressed under the
> wind patterns observed in 1997.
> The warm pool would probably have stayed in the east and not have
> retreated westward, the team found, significantly boosting the
> possibility of a strong 2014 El Niño event. The results indicate that
> if the antitrade winds don’t return, Vialard says, “this year’s El
> Niño is more or less dead.”
> And that’s bad news for the West Coast. California is in the midst of
> one of the most severe droughts on record and multiple large wildfires
> raged across the state this summer. Many had hoped El Niño would bring
> much-needed water to the region, which has received only 55 percent of
> normal precipitation so far this year.
> The root cause of this year’s El Niño dud remains unknown, says
> Michelle L’Heureux, a climate scientist for NOAA in College Park, Md.
> “The big question is why the winds weren’t as strong and rigorous as
> they were in 1997,” she says. Winds are difficult to forecast,
> L’Heureux explains, and contribute randomness into El Niño development
> and make the events difficult to predict.
> The uncertainty in part stems from the winds being influenced by
> atmospheric and oceanic conditions elsewhere on Earth, says climate
> scientist Kevin Trenberth of the National Center for Atmospheric
> Research in Boulder, Colo. The presence or absence of antitrade winds,
> he says, may be a by-product of the overall atmospheric changes that
> prompt El Niño as much as they are a cause.
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