Earlier this year I spent a week at the beach, more specifically at Bluey’s Beach, on the NSW mid-north coast. My daughter and partner are both keen surfers. So, always in search of that best wave break, we also visited Boomerang, Elizabeth, Seal Rocks and a few other beaches.
I’m used to southeast Queensland with the summer water temperature a very pleasant 26C or so, and expected the same in NSW.
But the first day we went surfing it was a very cold 14C!
So much for the global warming of sea temperatures I thought as I shivered on the beach that day.
The locals explained that it was unusual, but they didn’t seem to have a good explanation. Interestingly, the water wasn’t so cold every day or at every beach.
According to a recent article in Sydney’s The Daily Telegraph a “massive, mysterious whirlpool of cold water” formed off Sydney in January and is still active “forcing the sea surface to fall almost 1m and ocean currents to change course”.
So sea levels are falling off Sydney?
According to the CSIRO, oceanographers have identified a huge, dense mass of cold water off Sydney but know very little about what causes it.
“What we do know is that this is a very powerful natural feature which tends to push everything else aside – even the mighty East Australian Current,” says CSIRO’s Dr David Griffin.
Dr Griffin, from the Wealth from Oceans Flagship Research program, said cold-water eddies regularly appear off Sydney.
“Until 20 years ago we would not have known they even existed without accidentally steaming through them on a research vessel,” he said.
“However, now that we can routinely identify them from space via satellite, marine scientists can evaluate their role as a source of life in the marine ecosystem.”
Reaching to a depth of more than 1000m, the 200km diameter ocean eddy has a rotational period of about seven days. Its centre is about 100km directly offshore from Sydney.” [end of quote]
Now I’m waiting for a best AGW explanation for this dramatic, even if localized and ephemeral, drop in sea level and sea temperature.