NASA Study Reveals Oceans Temporarily Hide Global Warming

Oceans Temporarily Hide Global Warming

Temperature data from the global ocean (2003-2012) at four depths shows the warmest water at depths of about 330-660 feet (third panel from top) in the western Pacific and Indian Oceans. Credit: NASA Earth Observatory

A newly published NASA study shows that the recent extra heat from greenhouse gases has been trapped in the waters of the Pacific and Indian oceans, accounting for the slowdown in the global surface temperature trend observed during the past decade.

Researchers Veronica Nieves, Josh Willis and Bill Patzert of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California, found a specific layer of the Indian and Pacific oceans between 300 and 1,000 feet (100 and 300 meters) below the surface has been accumulating more heat than previously recognized. They also found the movement of warm water has affected surface temperatures. The result was published in the journal Science.

During the 20th century, as greenhouse gas concentrations increased and trapped more heat energy on Earth, global surface temperatures also increased. However, in the 21st century, this pattern seemed to change temporarily.

“Greenhouse gases continued to trap extra heat, but for about 10 years starting in the early 2000s, global average surface temperature stopped climbing, and even cooled a bit,” said Willis.

In the study, researchers analyzed direct ocean temperature measurements, including observations from a global network of about 3,500 ocean temperature probes known as the Argo array. These measurements show temperatures below the surface have been increasing.

The Pacific Ocean is the primary source of the subsurface warm water found in the study, though some of that water now has been pushed to the Indian Ocean. Since 2003, unusually strong trade winds and other climatic features have been piling up warm water in the upper 1,000 feet (300 meters) of the western Pacific, pinning it against Asia and Australia.

“The western Pacific got so warm that some of the warm water is leaking into the Indian Ocean through the Indonesian archipelago,” said Nieves, the lead author of the study.

The movement of the warm Pacific water westward pulled heat away from the surface waters of the central and eastern Pacific, which resulted in unusually cool surface temperatures during the last decade. Because the air temperature over the ocean is closely related to the ocean temperature, this provides a plausible explanation for the global cooling trend in surface temperature.

Cooler surface temperatures also are related to a long-lived climatic pattern called the Pacific Decadal Oscillation, which moves in a 20 to 30-year cycle. It has been in a cool phase during the entire time surface temperatures showed cooling, bringing cooler-than-normal water to the eastern Pacific and warmer water to the western side. There currently are signs the pattern may be changing to the opposite phase, with observations showing warmer-than-usual water in the eastern Pacific.

“Given the fact the Pacific Decadal Oscillation seems to be shifting to a warm phase, ocean heating in the Pacific will definitely drive a major surge in global surface warming,” Nieves said.

Previous attempts to explain the global surface temperature cooling trend have relied more heavily on climate model results or a combination of modeling and observations, which may be better at simulating long-term impacts over many decades and centuries. This study relied on observations, which are better for showing shorter-term changes over 10 to 20 years. In shorter time spans, natural variations such as the recent slowdown in global surface temperature trends can have larger regional impacts on climate than human-caused warming.

Pauses of a decade or more in Earth’s average surface temperature warming have happened before in modern times, with one occurring between the mid-1940s and late 1970s.

“In the long term, there is robust evidence of unabated global warming,” Nieves said.

Reference: “Recent hiatus caused by decadal shift in Indo-Pacific heating” by Veronica Nieves, Josh K. Willis and William C. Patzert, 9 July 2015, Science.
DOI: 10.1126/science.aaa4521

NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

5 Comments on "NASA Study Reveals Oceans Temporarily Hide Global Warming"

  1. It would be nice if the writer of this piece had bothered to compare these claimed findings with El Ninos which occur in the Pacific and with last years NASA study which showed no warming in the ocean depths. These two studies apparently contradict each other. It would seem this claim is simply the El Nino of which the last strong one was in 1997 and it brought 165 percent of normal snow packs to California.

    • @Michael, you need to either reread the original text of the 2014 NASA study of deep ocean temperatures or stop relying upon someone else’s second-hand faulty reading and interpretation of the 2014 NASA study.

      The following verbatim text is what the NASA website actually says about its 2014 study of deep ocean temperatures.

      “Scientists at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, analyzed satellite and direct ocean temperature data from 2005 to 2013 and found the ocean abyss below 1.24 miles (1,995 meters) has not warmed measurably.

      The temperature of the top half of the world’s oceans — above the 1.24-mile mark — is still climbing, but not fast enough to account for the stalled air temperatures.”

      There is no contradiction between the current study and the 2014 study. Both studies say that ocean temperatures are still climbing in the upper portion of the oceans. However, temperatures in the “deep” ocean (below a depth of 1.24 miles) have “not warmed measurably”.

      Although upper ocean temperatures are still climbing, the mystery still remains as to why this has not translated into a corresponding increase in air and land temperatures. Perhaps, it just takes a bit more time before the extra heat that is stored in the upper oceans is finally released and transferred into the atmosphere.

      Although 2014 was not an El Nino year, the 2014 study still found climbing temperatures in the upper oceans. Admittedly, the current 2015 study may be somewhat influenced by El Nino.

  2. what is unstated in this piece is the quality of the data. The argo system has pressure sensor problems effecting about 800 floats of the 3500 total. The floats dive down to 6000 feet and than float to the surface to send the temperature at various depths as measured by the pressure sensors. Than they dive again with an average age of four years before float failure. Those pressure sensor problems effect various years in varying amounts based on sensor model, age and software. The center also says they need more than 3500 as the northern and southern areas need more data due to various technical reasons. Since the pressure data tells you the depth, if the pressure data is adjusted during quality control one should have a good handle on what they did. It is quite possible the data is garbage in garbage out if the quality control is anything like the Giss or Best data sets. Those data sets quality control consists to throwing out any lower temperatures and plugging with higher average temperatures without any evidence the station measured temperatures are wrong. For example, raised Barrow Alaska 1.5 degrees from measured simply because they did not like the measured results, did that to thousands of station measurements.

  3. Ted Cruz (chairman of the Senate committee that funds NASA) better hurry and cut more of NASA’s funding before those dog-gone scientists reveal more of those pesky findings—with stories like this what are the Republican’s going to do—Oh, I know, they’ll just look the other way because, “I’m not a scientist!!!!”.

    • Funding is the problem with 99% of these “studies”. If the people funding your research don’t like your results, regardless of their accuracy, your study doesn’t get published, and then you’re stuck in the “publish or perish” world or science. Meanwhile, they go find a researcher that will manipulate the data to give them the results they want. If you want to see the cause of junk science, just follow the money. The researcher of today is no different than the herald of the middle ages. Shouting whatever he has been paid to shout to sway the hearts and minds of the masses.
      I don’t know if the planet is really warming, or if we are really the cause if it is. The data has been so manipulated, mangled, and twisted to match what the purse-holders what, I doubt anyone could really tell the truth of it anymore. I think the money trail says that even if we started into a new ice-age it would somehow be blame on man-made pollution. There are people with serious personal financial incentives in making sure “green” technologies are forced upon every human on the globe. No tin foil hat required to prove it, just follow the money…

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