Australia: Wind speeds and wave heights over the world’s oceans have been rising for the past quarter-century, according to Ian Young at the Australian National University in Canberra and colleagues. They analysed satellite data from 1985 to 2008 to calculate wave heights and wind speeds over the world’s oceans.
They found that winds had strengthened – speeding up over most of the world’s oceans by 0.25 to 0.5 per cent, on average, each year. Overall, wind speeds were 5 to 10 per cent faster than they had been 20 years earlier. However, it is unclear if this is a short-term trend, or a symptom of longer-term climatic change. Either way, more frequent hurricanes and cyclones could be on the horizon.
The results were compared against conventional measurements taken from deep-water buoys and numerical modelling. “There is variability, but the same general features are observed,” Young said.
Previous attempts to investigate these phenomena used observations from ships and buoys, but these could generally provide only a regional picture. Using altimeter data from satellites allowed the team to detect decadal trends on a global scale for the first time.