Hydrosphere Journal Entry
Hydrosphere Journal Entry
Oceans Keep Getting Warmer (May 31, 2010)
Graph shows changes in the heat content of the world's oceans since 1955. NOAA.
New research shows the upper layer of the world's oceans have grown much warmer in recent decades. Oceans absorb up to 90 percent of Earth's increased heat from global warming, according to NASA's Jet Propulsion Lab. Overall, the oceans warmed 0.3 degrees Fahrenheit since 1993. That doesn't sound like much, but it translates into a massive amount of heat considering the vastness of the world's oceans. In addition, global sea level is rising at the rate of 3 millimeters per year, three times faster than a century ago. The research looked at water temperatures from the surface to depths of 700 meters.
The study used a network of more than 3,000 free-floating sensors spread across the world's oceans. The sensors relayed data on temperature, salinity, and ocean currents directly to satellites overhead. This system gets more accurate results than ocean studies done with ships towing instruments called XBTs (or expendable bathythermographs) across the seas.
The graph shows the steep rise in the oceans' heat content, especially since the mid-1990s. Heat content is measured in units of 1022 joules. One joule is the amount of energy needed to lift a small apple off the ground.
