Sydney bathed in warm water

Craig Brokensha picture
Craig Brokensha (Craig)
Swellnet Analysis

Regardless of where you surf around the world, the end of winter and start of spring is usually when the ocean is at its coldest. This is due to a lag between the atmosphere and ocean, in that once the seasons start heating up again, it takes a while for this energy to be felt in the ocean. This is also why the warmest water is during the end of summer and the start of autumn.

However, this experience is at odds with the current conditions seen across most of the NSW coast, with water temperatures measuring way above average for this time of year.

A warm tongue of the East Australian Current has pushed a large body of 20 degree water to southern latitudes, 2 to 3 degrees above average (that being just below 18 degrees) for this time of year.

Only a few weeks ago, the water temperature was quite chilly - around 16 to 17 degrees - from Sydney south, but if you've paddled out recently, you'd have been heating up in your normal winter wetsuit.

The diagram opposite shows this tongue of warm water quite clearly, but why it's pushed so far south at this time of year is unknown. How low long it is going to last is also unknown - so enjoy the warmer water while you can!

Image courtesy of IMOS OceanCurrent

Comments

donweather's picture
donweather's picture
donweather Friday, 4 Sep 2015 at 1:40pm

I would imagine this will be short lived given the upwelling likely just around the corner now Spring has sprung.

Although obviously upwelling won't extend as far offshore as this warm water currently is.

freeride76's picture
freeride76's picture
freeride76 Friday, 4 Sep 2015 at 1:54pm

Yellowfin tuna

Craig's picture
Craig's picture
Craig Friday, 4 Sep 2015 at 1:58pm

Also worth noting is the water is clear as day, very little nutrients at all with in it.

The Tuna hang on the frontal zone Steve?

freeride76's picture
freeride76's picture
freeride76 Friday, 4 Sep 2015 at 2:00pm

Yep or in that slightly cooler eddy right below the main warm one.

memlasurf's picture
memlasurf's picture
memlasurf Friday, 4 Sep 2015 at 2:48pm

Craig send it down here. Quite chilly 16-17? Bah, humbug.

nochaser's picture
nochaser's picture
nochaser Friday, 4 Sep 2015 at 4:20pm

Early East Australian Current. I was looking at this on the SST's due to a past time of game fishing. I was thinking that only 4 fishes can pass thru the temp breaks that reside on all points of these currents. This is how you get massive bait balls the bait fish are unable to pass thru the temp break but Tuna ,Kingfish, sharks and marlin can. Massive temp breaks close to shore. Is this the reason why the sharks are in residence in Ballina Byron area. Look at the area below Port Stephens like Sydney misses a Sth swell we also miss the EAC.
Last time I was in SW WA was DEC 2013 after all the attacks a mate said don't bring a wetsuit it is stupidly warm. Whites and 20 degree water in migration period. The south coast also had a problem this year would love to know the stats on the water temp.
On another site I saw Margaret River as 20 degrees, Lennox 19 degrees... lets see some tag information CSIRO.
Anyone know about freedom of information laws regarding CSIRO data.

matt59's picture
matt59's picture
matt59 Friday, 4 Sep 2015 at 6:14pm

Agree It would be good to analyse data on water temps and shark numbers/attacks, somethung is different on the east coast at the moment. Any better insight to shark behaviour would be appreciated. For an animal that has been around for millions of years, we don't know much about them, pretty mysterious bastards.

andrew-pitt's picture
andrew-pitt's picture
andrew-pitt Friday, 4 Sep 2015 at 6:19pm

Interesting theory about warm currents and sharks Nochaser, hope you expand.
With a multi-mega million $$ budget, CSIRO is running the Atlas of Living Australia www.ala.org.au Essentially this is 'citizen science; sharing biodiversity knowledge to shape our future', all data is freely available under a Creative Commons licence. Heaps of data sets there, more to come. Though my search discovered nothing on "shark attacks" or "East Coast Current"...

freeride76's picture
freeride76's picture
freeride76 Friday, 4 Sep 2015 at 7:36pm

19 degree water is bog standard temp for Lennox-ballina in winter/spring.
From my observations I don't think water temps at least inshore are significantly different this year in the Le-BA area.

nochaser's picture
nochaser's picture
nochaser Friday, 4 Sep 2015 at 7:53pm

Freeride Bog standard BUT when the temp isn't running downhill they have been know to congregate further north Rockhampton area.
The tagging from the other mob ocearch Hawaii wasn't thought to be Whitey area but they migrate out that way, bet you they hit the wall at @ 20 degrees. My theory.
Will have a look Andrew-Pitt.
Another interaction at Foster...it's off the hook.