Missing Energy Found In Warming Deep Oceans

In the last half-century, as the Earth continued to warm, the oceans absorbed 90% of the heat.  That remaining 10% melted sea and land ice and warmed our land and atmosphere.  Just 10% did that.  You can now thank the oceans for saving us from ourselves. Go ahead I’ll wait.

In 2000 something drastically changed. Ocean temperature at the sea surface stopped rising. The absorption of this thermal energy stalled while increasing greenhouse gases should increased warming.  Where did this missing energy go?

New research has found this missing energy in the deep oceans.  The findings rise from a model (ORAS4) tested against and based on temperature and salinity data from 1958-2009, at least a dozen different data types, and all over the worlds oceans.  This is massive undertaking and represents our best estimates of changes in the ocean’s heat, i.e. thermal energy, over the last half century.

OHC integrated from 0 to 300 m (grey), 700 m (blue), and total depth (violet) from ORAS4, as represented by its 5 ensemble members. The time series show monthly anomalies smoothed with a 12 month running mean, with respect to the 1958–1965 base period

OHC integrated from 0 to 300 m (grey), 700 m (blue), and total depth (violet) from ORAS4, as represented by its 5 ensemble members. The time series show monthly anomalies smoothed with a 12 month running mean, with respect to the 1958–1965 base period

Ash cloud

Ash cloud above Mt. Pinatubo.  If we could just have another of these, we would be set.

The figure above outlines clearly where the heat is going—the deep oceans.  The deepest oceans (purple line) have risen in heat content much greater than the oceans at 300 meters and less.  Indeed, this discrepancy in energy uptake by different ocean depths appears to have started in the beginning of this century.

To give you some perspective the deep oceans in 2008 took near 20*1022 Joules (2*1015 Gigajoules).  The average person in the U.S. uses about 301 Gigajoules of energy.  So in 2008, the deep oceans took in the equivalent energy of that produced by 6,644,518,300,000 people (>6.6 trillion people). The current population of the world is just over 7 billion.  Take a moment to let that settle in. Go ahead I’ll wait.

The figure above also show some interesting cooling periods following major volcanic eruptions—Agung,El Chichón, and Pinatubo. The last eruption in June of 1991 was the second largest eruption in the last century.

It ejected roughly 10,000,000,000 tonnes (1.1×1010 short tons) or 10 km3 (2.4 cu mi) of magma, and 20,000,000 tonnes (22,000,000 short tons) SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of aerosol into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C (0.9 °F), and ozone depletion temporarily increased substantially.

The bad news is that the deep oceans, the very inspiration of this blog, are on a long-term trajectory to a boiling pot of water. On the upside we are all just one catastrophic volcanic event away from cool bliss.

Magdalena A. Balmaseda, Kevin E. Trenberth and Erland Källén Distinctive climate signals in reanalysis of global ocean heat content Geophysical Research Letters 40 Article first published online: 10 MAY 2013 | DOI: 10.1002/grl.50382

Dr. M (1801 Posts)

Craig McClain is the Executive Director of the Lousiana University Marine Consortium. He has conducted deep-sea research for 20 years and published over 50 papers in the area. He has participated in and led dozens of oceanographic expeditions taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses on how energy drives the biology of marine invertebrates from individuals to ecosystems, specifically, seeking to uncover how organisms are adapted to different levels of carbon availability, i.e. food, and how this determines the kinds and number of species in different parts of the oceans. Additionally, Craig is obsessed with the size of things. Sometimes this translated into actually scientific research. Craig’s research has been featured on National Public Radio, Discovery Channel, Fox News, National Geographic and ABC News. In addition to his scientific research, Craig also advocates the need for scientists to connect with the public and is the founder and chief editor of the acclaimed Deep-Sea News (http://deepseanews.com/), a popular ocean-themed blog that has won numerous awards. His writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web.

2 Replies to “Missing Energy Found In Warming Deep Oceans”

  1. Doc M, great article on this important paper, just want to note that the spelling of the volcano is El Chichón.

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