Surprising Depth to Global Warming Effects
Antarctic Bottom Water has become warmer and less salty.
The warming in the deep Southern Ocean alone accounts for 34 terawatts of warming, roughly equivalent to the continuous operation of three 1,500-watt electric teakettles for each of the 7 billion people on the planet.
Sarah Purkey (UW Oceanography)
Gregory Johnson (Pacific Marine Environmental Laboratory)
In three recent publication Sarah Purkey and Gregory Johnson write about their research on properties of Antarctic bottom water.
The oceans are the flywheel of the climate system. As atmospheric concentrations of greenhouse gases increase, the Earth system is warming, and over 90 percent of that increase in heat goes into the ocean. Knowing how much heat the ocean absorbs is vital to understanding sea level rise (the oceans expand as they warm), and predicting how much, and how fast, the atmosphere will warm.
Most estimates of ocean warming have been limited to the upper 700 meters of water, owing to the limited availability of ocean-temperature data below that depth. Since about the turn of the millennium, the Argo array, an international system of robotic profiling floats, has massively increased ocean sampling to 2,000 meters, and allowed scientists to show conclusively that ocean warming extends below 700 meters.
"Surprising Depth to Global Warming's Effects" (in Live Science)
"Oceanography: Rise from below" (in Nature Geoscience)
"Antarctic Bottom Water warming and freshening: Contributions to sea level rise, ocean freshwater budgets, and global heat", Journal of Climate 2013, American Meteorological Society ; e-View doi: http://dx.doi.org/10.1175/JCLI-D-12-00834.1