THERE are 3,000 free-drifting buoys in the world’s ocean; first deployed in the year 2000 they allow continuous monitoring of the temperature, salinity, and velocity of the upper ocean.
There has though been some difficulty in interpreting the data from these buoys. Initial signs of cooling were dismissed as due to technical errors subsequently corrected based on a small sample of the 3,000 buoys known as profiling floats.
Craig Loehle has analysed the data from only the profiling floats for ocean heat content from 2003 to 2008. In a paper recently published in the journal Energy and Environment he has concluded that there has been ocean cooling over this period.
This graphic is from figure 1 of the technical paper and shows the decline in ocean heat content (x1022J) smoothed with a 1-2-1 filter.
Dr Loehle’s findings are consistent with satellite and surface instrumental records that do not showing a warming trend over recent years.
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.