From the
signals that I have seen, I am prepared to make one conjecture. It is possible that climate is shifting from
North Centric back to South Centric.
This may actually meant that we will enter an interim period in which
the center will dominate.
The fact
remains that the Arctic has cooled off and that Antarctic ice is suddenly
breaking up and retreating. I still have
to see measurements and all that but we should see confirmation over the next
two months.
An el Nino
event now would be just about right.
El Niño: Is 2014 the new 1997?
May 19, 2014: Every ten days, the NASA/French Space Agency Jason-2 satellite maps all the world's oceans, monitoring changes in sea surface height, a measure of heat in the upper layers of the water. Because our planet is more than 70% ocean, this information is crucial to global forecasts of weather and climate.
Lately, Jason-2 has seen something brewing in the Pacific—and it looks
a lot like 1997.
"A pattern of sea surface heights and temperatures has formed that
reminds me of the way the Pacific looked in the spring of 1997," says Bill
Patzert, a climatologist at NASA's Jet Propulsion Laboratory. "That turned
out to be the precursor of a big El Niño."
A new ScienceCast video examines the evidence that an El Niño is
developing in the Pacific. Play it
"We can't yet say for sure that an El Niño will develop in 2014,
or how big it might be," cautions Mike McPhaden of NOAA's Pacific
Environmental Research Laboratories in Seattle, "but the Jason-2 data
support the El Niño Watch issued last month by NOAA."
What Jason-2 has been seeing is a series of "Kelvin
waves"—massive ripples in sea level that travel across the Pacific from
Australia to South America. Forecasters are paying close attention
because these waves could be a herald of El Niño.
The two phenomena, Kelvin waves and El Niño, are linked by wind.
Pacific trade winds blow from east to west, pushing sun-warmed surface waters
toward Indonesia. As a result, the sea level near Indonesia is normally
45 cm higher than it is near Ecuador. Researchers call that area the
“warm pool”—it is the largest reservoir of warm water on our planet.
Sometimes, however, trade winds falter for a few days or weeks, and
some of that excess sea level ripples back toward the Americas.
"That's a Kelvin wave," says McPhaden. "It's not unusual to see
a couple every winter."
El Niño happens when trade winds falter not just for days, but for many
months. Then Kelvin waves cross the Pacific like a caravan,
raising sea level and leaving warmer equatorial waters in their wake.
On May 8th, the National Centers for Environmental Prediction
forecasted a 65% chance of El Niño developing during the summer of 2014. More
"The El Niño of 1997/98 was a textbook example," recalls
Patzert. "At that time we were getting data from TOPEX/Poseidon, a
predecessor of Jason-2. Sea surface maps showed a whitish bump,
indicating a sea level some 10 centimeters higher than usual, moving along the
equator from Australia to South America."
"The same pattern is repeating in 2014," says McPhaden.
"A series of Kelvin waves generated by localized west wind bursts in the
western Pacific that began in mid-January 2014 are headed east. Excitement is
building as a third weakening of the Pacific trade winds happened in mid-April."
Ocean and atmospheric scientists at NOAA and NASA are carefully
monitoring the Pacific trade winds. The tipping point for declaring a
significant El Niño will be an even longer lasting, larger collapse in Pacific
trade winds, possibly signaling a shift in weather all around our planet.
"It will become much clearer over the next two to three months
whether these recent developments are the forerunner of a major El Niño—or any
El Niño at all," says McPhaden.
"Jason-2 is a marvelous Kelvin wave counter," adds Patzert,
"and it will tell the tale."
Credits:
Web Links:
The El Nino Winter of 1997-1998 -- a technical report from tthe
National Climatic Data Center
Jason 2-- home page
No comments:
Post a Comment