This year, we were told , was a 'balanced year' (sic). El-Niño years have become more common since the warming trend has taken off.
Study
Sounds ‘El Niño Alarm’ For Late This Year
A
new study shows that there is at least a 76 percent likelihood that
an El Niño event will occur later this year, potentially reshaping
global weather patterns for a year or more and raising the odds that
2015 will set a record for the warmest year since instrument records
began in the late 19th century
10
February, 2014
The
study, published
on Monday in
the Proceedings of the National Academy of Sciences, builds
on research put
forward in 2013 that first proposed a new long-range El Niño
prediction method.
Although
they occur in the equatorial tropical Pacific Ocean, the effects of
El Niño events can reverberate around the globe, wreaking havoc with
typical weather patterns. El Niños increase the likelihood
for California to be pummeled
by Pacific storm systems,
for example, while leaving eastern Australia at greater risk of
drought. Because they are characterized by higher than average sea
surface temperatures in the equatorial tropical Pacific Ocean, and
they add heat to the atmosphere, El Niño events also tend to boost
global average temperatures.
By
acting in concert with manmade greenhouse gases, which are also
warming the planet, calendar years featuring a strong El Niño event,
such as 1998, can more easily set all-time high temperature records.
Today,
scientists can only reliably predict the onset and severity of El
Niño events by about 6 months ahead of time. And this lead time may
actually decrease due to Congressional budget
cuts for
ocean monitoring buoys that provide crucial information for El
Niño forecasting.
The
new study, by an international group of researchers, takes a starkly
different approach to El Niño forecasting compared to conventional
techniques. While the forecast models in use today tend to rely on
observations of the ocean conditions and trade winds that generally
blow from east to west across the tropical Pacific, the new method
relies on an index that compares surface air temperatures in the area
where El Niño events typically occur with temperatures across the
rest of the Pacific.
“Our
approach uses another route,” said study coauthor Armin Bunde, a
scientist at the Institute for Theoretical Physics in Giessen,
Germany, in an email conversation. “We do not consider the water
temperature in a specific area of the Pacific Ocean, but the
atmospheric temperatures in all areas of the Pacific.”The
researchers found that a strong link between air temperatures across
the Pacific and air temperatures in region where El Niño
forms appears about one calendar year before an actual El Niño
event. Taking advantage of this observation, the scientists devised a
forecasting index based on the strength of the links between
temperatures in and around the El Niño region. This index, the study
said, points to a high likelihood of an upcoming El Niño late in
2014.
While the the study claims to be more definitive than other forecasts, projections derived from ocean- and statistically-based models from the National Weather Service and the International Research Institute for Climate and Society (IRI) at Columbia University already show increasing odds, to the tune of twice the average risk, of an El Niño starting in the late summer or early fall as well.
Some
leading El Niño forecasters were skeptical of the new study, in part
because it puts forward a technique based only on statistics, with no
improved understanding of the underlying physics of the Pacific Ocean
and atmosphere. Bunde told Climate Central that he and his colleagues
have yet to discover the physical connections between the rest of the
Pacific and the El Niño region, but that they are still
investigating.
"This
is classic bravado — they make a forecast: if it is wrong, everyone
forgets; if they are right, they get big points. In the meantime,
people cite their papers," said Lisa Goddard, director of IRI
and a senior scientist there. "There is no physical explanation
of what is going on."
Bunde
said the temperature index method is more reliable than traditional
forecast techniques.
“When
we give an alarm, the alarm is correct in 3 of 4 cases and false in
1,” Bunde said. “We can forecast El Niño about 1 year ahead. The
conventional forecasts have a considerably shorter warning time of
about 6 months, with a lower hit rate than our method. The
disadvantage of our method is that we cannot predict the strength of
the El Niño event. But we hope to overcome this shortage of our
algorithm in the near future.”
Bunde
said the extra 6 months of warning time could have significant
economic benefits, since it covers an entire “agricultural cycle,”
thereby giving farmers more time to adapt to wetter or drier than
average conditions.
In
the study, the scientists said they are aware of “the reputational
risks” involved with making an El Niño prediction so far in
advance. “Should our alarm turn out to be correct, however, this
would be a major step toward better forecasting,” the study said.
However,
Anthony Barnston, chief forecaster at IRI, told Climate Central that
the new method is not likely to stand the test of time. "This
scheme shows a good performance now, but after another 6 years (and 2
new El Niños) it may not look nearly as good, and they will have to
change something to restore skill," he said.
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