The biggest waves on Earth are getting bigger
Rightio, here's another of those science stories that surfers love to read because the findings not only apply to us, but they also bring good news.
Not good news for everyone, but good news for surfers.
A study released by scientists at the University of Melbourne last week showed that wave heights around the globe are increasing, and best of all, the largest rise is occurring in the Southern Ocean.
The study, by Ian Young and Agustinus Ribal, was done by retrospectively looked at 33 years worth of satellite readings. And here's some information for those of you partial to the power of a really big number: Over 33 years the scientists gathered readings from 31 satellites totalling an impressive 4 billion observation points.
The readings were derived either by altimeters - instruments that bounce energy pulses off wave crests and measure their return time - or by instruments that measure the reflectivity of the ocean surfaces to estimate the speed of ocean winds.
The measurements were compared with more than 80 wave buoys deployed worldwide, making it the largest and most detailed dataset of its type ever compiled.
Young and Ribal found that since 1985, average ocean wind speeds have increased between one and two centimetres per second per year, leading to increases in wave height around the world.
However, the changes weren't evenly spread, the largest increases were found to occur in the top 10% of waves (according to height), with some ocean basins increasing more than others.
In the Southern Ocean, the trends are particularly strong. For instance, although average wave heights there have increased by just 0.3 centimetres per year, the top 10% of waves has grown by an average of one centimetre per year—a growth of thirty centimetres since 1985.
The new study doesn’t say definitively why wave height and wind speed is changing, although Young suspects a link with climate change.
“These are the secondary effects of climate change, not the obvious ones like sea level rise,” Young says, adding that, "understanding how waves change is critical to assessing the impacts of climate change at the coast." Coastal inundation due to sea level rise will be exacerbated if there is more wave energy on the coast.
So there you have it, your good news story for the day. Earth's atmosphere may be caught in a runaway greenhouse effect leading to rising seas, shifting seasons, and failing crops, all of which will threaten food security and the peace in which we live, but hey, at least the surf will be bigger!