As 2015 Begins With Record Warmth, is the Pacific Primed to Dump Huge Amounts of Heat Into the Atmosphere?

By Tom Yulsman | April 18, 2015 3:07 pm


It’s official: According to NOAA’s National Climatic Data Center, the first quarter of 2015 has set a new record, with the January through March period coming in as the warmest such period on record across the globe’s land and ocean surfaces.

The month of March was also ranked warmest by NCDC in a record dating back 136 years. The Japan Meteorological Agency concurs, whereas NASA, which does its own independent analysis, ranked March as third warmest. That’s a distinction without much of a difference since the estimates of all three agencies are very close to each other.

Two climatic factors may now be conspiring with humankind’s emissions of heat-trapping greenhouse gases to push the globe toward an entire year of record warmth: El Ni単o and a broader phenomenon known as the Pacific Decadal Oscillation.

First, let’s consider El Ni単o, which is one side of a climatic pattern called the El Ni単o-Southern Oscillation, or ENSO.During an El Ni単o, heat stored in the tropical Pacific Ocean is released into the atmosphere, which tends to give a boost to global average temperatures. NOAA’s latest forecast is for a 70 percent chance of El Ni単o continuing through summer and a 60 percent chance that it will persist through the fall.

SEE ALSO: Odds of El Ni単o Continuing Through Summer Upped to 70%

It bears mentioning that El Ni単o’s evolutionover the past year did not go according to the forecasters’ script. Butin March, developments in the tropical Pacific pointedpretty strongly to El Ni単o continuing. As Emily Becker put it in NOAA’s ENSO blog recently:

Last month, we saw the first signs of an atmospheric response to the warmer-than-average sea surface temperatures that had been in place in the tropical Pacific for several months, leading us to declare the presence of El Ni単o conditions. In March, those conditions strengthened a bit.


Wind departures from average in the tropical Pacific during March 2015. Purple shading indicates the location of the westerly wind burst. (Source: NOAA figure by Fiona Martin, based on Climate Prediction Center data.)

The map above depicts one strong signthat the atmosphere and ocean are now responding together in a way that’s indicative of El Ni単o. The arrows show the direction of the winds during March in a large portion of the Pacific Ocean. Note the purple shading, which indicates a particularly strong burst of winds blowing in the direction of those arrows from west to east.

Ordinarily, trade winds along the equator blow in the opposite direction. This helps bottle up warm surface waters in the western part of the tropical Pacific. But here, they’ve reversed, helping warm water to flow toward the east. This is a hallmark of El Ni単o.

In fact, the purple area on the map above depicts a burst of westerly winds (out of the west) that was the strongest since 1997. And at that time, a monster El Ni単o was brewing. Current forecasts don’t call for anything as strong as that El Ni単o event. But once again, nature does have a way of surprising us. We’ll just have to wait and see.

In the meantime, the other phenomenon the Pacific Decadal Oscillation is worth keeping an eye on. In terms of its effect on sea surface temperatures in the Pacific, it is akin to El Ni単o, but its pattern is broader, and whereas El Ni単o is a phenomenon that takes place over an annual timescale, the PDO occurs over decades.

During thatmonster El Ni単o in1997 and 1998,an enormous amount of heat was released from the Pacific Ocean into the atmosphere, helping to make that year the warmest on record up until that point.By releasing all of that heat, the tropical Pacific cooled. A year later, the broader PDO switched intowhat’s known as its negative phase and it stayed there until just a few months ago.

During this same long period, the rise in the Earth’s global average surface temperature slowed down, something that skeptics have seized on to cast doubt on humankind’s impact on the climate. That impact never was in scientific doubt, since multiple lines of evidence from shriveling glaciersandshrinking Arctic sea ice to increases in the heat content of the oceans pointed to continuing climate change resulting from humankind’s influence.

But why did the warming of the globe’s surface slow down? Ordinarily, 90 percent of the heat that builds up in the climate system winds up getting absorbed in the ocean. Researchby Kevin Trenberth and John Fasullo of the National Center for Atmospheric Research has shown that during thePDO’s negative phase over the past decade, more than 30 percent of that heat seems to havepenetrated below 700meters in the ocean.

In other words, it has been locked away so deeplythat it has not been able to heat the atmosphere. But as signs point to a reversal of the PDO pattern, now thatheat may be primed to start comingback out of the ocean.


A measure of the Pacific Decadal Oscillation shows it flipping into a positive phase during the past few months. (Source: Japan Meteorological Agency)

Thegraph above shows how the PDO has switched between negative (blue) and positive (red) phases.Look all the way to the right. See that red spike?

Next, check out the map below. It shows the typical pattern of sea surface temperatures during the positive phase of the PDO.

Note that big red blob of warm water in the tropical Pacific, with an extension up along the west coast of North America, as well asthe cold blue blob in the northern portion of the central Pacific. Now, compare this map with how things have actually developed in the Pacific during the past four months:


Notethat abnormally warm water along the equator on either side of the dateline, along with its extension up along the coast of North America, as well as the cold patch in the northern Pacific?

These conditions are indicative of a positivePDO. But will they persist fora decade or longer, allowing even morestored heat to come pouring out of the ocean and into the atmosphere, helping to accelerate global warming? Or will the PDO drop quickly back into its negative phase? As with the shorter-term phenomenon of El Ni単o, we’ll have to wait and see.

Meanwhile, a study published April 13in the journal Nature Climate Change shows that an even longer-term phenomenon related to the PDO could be primed to flip. It’s known as the Interdecadal Pacific Oscillation, or IPO. As the authors put it:

Recent history suggests that the IPO could reverse course and lead to accelerated global warming in the coming decades.



  • Sirius_TheStarDog

    “Look all the way to the right. See that red spike?” Next … look to the left and see those red spikes during the late ’50s during the previous cool phase? Humm…

    • Tom Yulsman

      Mr. Sirius_TheStarDog: Did you even bother to read the article? It would seem not. The point is that the Pacific Decadal Oscillation has two long-lasting phases, and we’re coming out of one and entering another. What about that very simple idea do you not understand?

      • Sirius_TheStarDog

        There’s no evidence of a shift from cool to warm. My point: during past cool phases there were warm spikes and vice versa. What about that very simple idea do you not understand?

    • Sendus Czswag

      Yeah, but the # of people on the planet and the # of automobiles, power consumption, etc. is not the same as it was in the late 1950’s.

      • Sirius_TheStarDog

        Totally irrelevant as to whether the PDO flipping from cool to warm.

  • OWilson

    Simple answer to your question?


    There will be no unusual “Huge Amounts Of Heat Dumped Into The Atmosphere”

    When you go from one drastic scenario to another you contribute to the general distrust of climactic scientific predictions. It gets tiresome. Scary hyperbolic headlines, then failed predictions acknowledged further down.

    People start ignoring Chicken Littles and Boys who constantly Cry Wolf.

    Explains why the polls show a declining concern with Climate Change.
    In some cases, like movie theatres, they actually remove those who constantly shout, “Fire”.

    • Tom Yulsman

      Thank you for your contribution.

    • Mike Richardson

      Funny, but don’t you get pretty worried when someone mentions arresting global warming deniers for delaying meaningful action on climate change? To take your analogy, it would be akin to someone in a theater telling people to stay put and not worry when there is in fact a fire that endangers them. That would be anti-social behavior, too. And you’ve never engaged in hyperbole, right? So I think we should probably not talk about arresting people for discussing an issue of importance. You can have your say, and the people with the facts on their side can have theirs. Goodnight, my man.

    • Sparafucile

      Interestingly, where Tom sees a positive phase to the PDO, I look at the same graphical data and draw the opposite conclusion. See the gigantic warm(er) triangle off the coast of Central and South America?

      Also — look at the entire oceanic set between 2013 and 2015. 2015 is indisputably cooler, worldwide. What happened to “all the heat is going into the oceans”?

  • timallard

    Right now the jetstreams are so altered in what they are doing versus a Holocene atmospheric pattern, they’re just moving heat north, cold south as efficiently as possible, that drives Eckman currents, those do affect large vortex-like current flows caused by them and continental-to-seafloor profiles that can drive turnovers at the margin of major ocean currents over time.

    From a recent Holocene drought 8,000-4,000 years ago a period called the Altithermal of 1C heating due to orbital variation that took 1200賊200 years at 265-ppm CO2 to heat that much & are lessons that this dried out most of the midwest, SW & west with a strip of desert from West Texas to almost Canada. For the Lower Colorado River the Mohave Tribe went from hunter-gather in local forests to flood agriculture at the end and continue with commercial ag today.

    It was literally a 2,000-year period of drought in the middle and this from jetstream transitions in latitude from a glacial to interglacial forcing of these winds plus extra warming in summer. [long-term droughts are a group of years from 3-30 of severe drought with not much time or enough moisture held in between so the hydrologic cycle can’t recover].

    This was global, at the same time the Sahara at the beginning had major mega-lakes with north-south drainages to the Med from south of Chad and at the end it was desert and the larger cities rose from a depopulation of that expanse to where there was water.

    Our forcing is way beyond a tweak to the orbit.

    So that’s the record to go by on a 1C rise with normal forcing likely 1/20th the greenhousing power of jumping CO2 120-ppm in only two centuries.

    The oceans are the thermal-mass of the planet, not the air or land which can’t hold heat like water and it’s always in motion globally so always interchanging heat from the surface to the bottom on time scales from decades to 1,200 or more years.

    In the deep ocean salinity counts more than temperature so heating saline bottom water and raising its buoyancy is a big deal, normally upwelling is along coasts dictated by the profile, descending only happens a few places the famous one in the North Atlantic turnover with a descending saline flow that’s warmer than the less saline colder water below it, the Gulf Stream’s remnants.

    In the Pacific the east-west changes are well noted for ENSO yet where are the descending zones, to me those are tied to the IPO?

    I think those control the decadal turnovers in a roll vortex that can be driven by jetstream effects on trade winds over time. What deep dynamics can operate on decadal scale to move a lot of heat, all I can imagine is a large roll vortex that exists is getting a touch of acceleration from the change in density on a side.

    The article states about 30% of the heat is getting to below 700m, others state 21% to 2000m so not much lost to that deep from Argo buoy data, that means the heat transfers are far faster than the water it affects, thus there can already be a gain in buoyancy quite deep that would add to the vortex rotation on its radial velocity & radius.

    If you look at when the westerly bursts happen then correlate that to what the jetstreams were doing, instead of curving north as a unit the Northern Temperate Jetstream often splits leaving S. China coast part going south in the direction of the burst flow supply, the rest north to Alaska now carrying heat & moisture then drier & cold moving cold south to snow in NJ when it hits the southern let again.

    Overdrive, we need to take the foot off the gas.

  • Bob Bingham

    If we get an El Nino then California may get some rain, which would be a help but then someone else would get a drought or a storm. What we don’t want is a drought in Florida.

  • Harmonica Rayes

    When I moved to California 14 years ago, there was record rainfall, followed by record heat the next year. Being a native Minnesotan, I am used to extreme weather. Sometimes we would have tornado’s followed by a foot of snow a few days later. I have seen the temperature change over 50 degrees in as little as 48 hours. I now live in Portland, where I was told it would be cloudy and or rainy with very little snow and moderate temperatures. But… I believe 2009 was extreme heat that year, followed by snow that the locals hadn’t seen in more than 40 years. And quite honestly, I have experienced more sunshine here overall, than in Minnesota. Each place I have lived, I have checked out the averages, but I do not see any patterns. Therefore, I’m asking. Can we really predict all of this?
    Thank you



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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