Investigators previously determined climate models can replicate ocean warming observed during the latter half of the 20th century. They also found substantial variability in ocean heat content on yearly to decade-long time scales.
The latest study by Lawrence Livermore National Laboratory scientists demonstrates climate models represent such variability much more realistically than previously believed.
The researchers said their study casts doubt on recent findings that the top 2,300 feet of the global ocean cooled markedly from 2003 to 2005.
"Our analysis shows the 2003-2005 'cooling' is largely an artifact of a systematic change in the observing system," said Krishna AchutaRao, a former Livermore scientist now at the Indian Institute of Technology. "The previous research was based on looking at the combined ocean temperature observations from several different instrument types, which collectively appear to have a cooling effect. But if you look at the observational instruments individually, there is no cooling."
The study appears in the early online edition of the Proceedings of the National Academy of Sciences.