How to predict ocean conditions in Queenslands South East.    

All information by the aandtsociety.org.au

 

This is designed to give others the capacity to work out, for their water sports, what the ocean will be like before you arrive at it and know what is being affected and why.

 

Firstly this will cover the Gold coast and on to Moreton bay, Stradbroke and Moreton Islands and lastly the sunshine coast.

 

Gold Coast area.

 

This information is how to work out what area will be good or bad, what a big swell or small swell may affect, low water visibility or clean and tidal affects when larger or smaller tides are present, hours or days before you go there!

 

Winds affecting the ocean in one particular way that influences so much of our coastline conditions.

 

If the wind is blowing along the surface of the ocean it will be pushing the oceans surface waters along with it and where the waters have been pushed along, there has to be waters to replace these, which happens at some depth beneath.

 

The winds make a circulating affect upon the ocean, it blows the surface waters out to sea and the waters out there move beneath towards where the surface waters came from to replace them, this is how an off shore wind, from the land out to sea, clears the shore line waters visibility.

 

This if watched could be applied in any ocean area to work out where the water will be clear or dirty or has current!

 

Winds and their affects.

 

If winds at any given time are from the south-east to east, if strong enough or prolonged exposure, these will benefit the gold coast waters greatly by bringing in some of the clearer-warmer waters from off shore with in the east Ausy current that may be active out off us at the time of these winds.

 

These wind directions will bring the surface of the outer ocean currents in to shore, making ocean conditions improve normally.

 

This is of course if there have been no severe rains further north that may have flushed the rivers rich in organic matter out to sea to be picked up by the east Auzy current and swept along with the ocean processing these organics, mainly via phytoplankton as it goes along.

 

If this has occurred the waters that are pushed in will not be of a great benefit and the oceans shoreline and may adversely reduce visibility and lower ocean temperatures.

 

The major contributor to low visibility on the gold coast is the jumping pin bar that is fed mostly by the very dirty waters of the Logan River and southern Moreton bay.

 

This high in organics and tea tree coloured waters congregates around the river mouth area depending on which way the swell is facing or which wind is blowing, this is normally moved out to sea and picked up by the east Ausy current (mostly).

 

When winds from the north-north east are occurring, this direction of winds will push the dirtier waters against the shoreline and then south to the south port seaway.

 

By the second day of winds from the north-northeast the dirtier waters arrive at the south port seaway reducing the visibility and quite often, ocean temperature.

 

This is because low visibility waters well beneath the surface, normally run cooler than clearer waters.

 

With in three to four days from the north winds starting, the dirty waters are arriving as far south as the tweed river to reduce the visibility as well as the whole gold coast, some times dirtying the waters from the jumping pin bar all the way to Byron bay if the winds from the north-northeast blow for long enough.

 

Tides and their affects.

 

If high tides are large, than there is normally a large current due to the high tide being so far away from the low tide in size.

 

This means that if the high tide is at 2.30 and than the low tide after or before it may be 0.45,that equates to a movement of 1.85 meters of water, between high and low tide.

 

That is a lot of water to move in a 6-hour cycle between high and low tide, especially in a narrow area like the sea way.

 

This causes a strong current in the estuaries and to some degree influences the open ocean currents as well.

 

If the there is a large area of water well in from the bar like the south port area and Tallebudgera lake and than just inside the Currumbin bar to the bridge and up stream in the tweed river, from large waters to large waters you get a very strong current between the open ocean and these sizable expanses of water as it narrows before opening into the open ocean an defuses.

 

One good thing about a large tide and the subsequent strong current, the larger tide will bring in waters from further out to sea to replace the immense amount of water movement and most likely drag in to shore clearer waters for the high tide.

 

When there is a large tide change, the time the waters stand still as the tide changes is far shorter than a smaller tide change, so the waters will remain still for less time to enjoy still waters!

 

The oceans off shore also have something very special with in them, billions and billions of new life with in!

 

Nearly all marine life forms dispatch their off spring as eggs, larvae what ever as planktonic sized life (normally transparent for a while or just very tiny) into this current to be moved along for their chance at life else where.

 

Once they are to big to remain as planktonic sized creatures, or sense a reef via clicking reef life sounds or wave sounds, they leave the planktons safety to hopefully find their now home.

 

These get blown in as well depending on what time of year have dispersed their replacements to be sent on their way to begin their lives and 99 percent do not do not make it, for many reasons!

 

So when you see a strong north easterly, or the better life dispersal, easterly and south-easterly winds blowing quiet strong, billions of new life forms are being pushed onto the coast with it and start showing themselves in the coming months as they grow!

 

 

Swells.

 

Due to the amount of estuaries from the jumping pin bar along the entire gold coast, these contribute immense amounts of sediment to the gold coast in general.

From these come a build up of sediment on the oceans floor along the gold coast at depths that are not affected by average swell sizes.

Smooth seas that normally prevail up to 1.2 meters of swell size from on average do not overly disturb this build up of ocean floor sediment.

Any greater than this and the more intense sediment will be disturbed on the oceans floor and be pushed into shore by the swells direction which is always towards the shore line.

 

If the swell is 1.0 to 1.2 on Monday, the visibility will still be acceptable, once the swell hits 1.5 meters or greater, by the next day the waters visibility is diminishing!

 

Corn flake weed.

 

This due to global warming is becoming less of an issue more so from when South East Queensland began to suffer greater affects of global warming, increasing ocean surface temperatures more than anything else.

 

This equates to depths down to around 70 feet of water.

 

The oceans thermo clines below 70 feet on average are still roughly at normal temperatures,(from as cold as 14c to 20c)these on average only slight increases at these depths.

 

The more shallow depths of SEQ ocean areas are the more influenced and this began to be very profound from the years 2000 through to 2006,from there the oceans here in the south east are averaging 2 degrees higher and now in the 2010s,the temps are another 1 degree higher in winter but not much difference to the surface temperatures in the warmer months!

 

What would normally occur with the cornflake weed is through out winter this algae/plant would thrive in areas to just over the border into Queensland and do okay in small communities as far north as the south port seaway and some slight amounts as far north as the sunshine coast.

 

As the winter water temps begin to subside these algae/plants would go to spore and combined with some raised swells, masses of what you could call the plants leaves would literally coat the entire coast line, at times choking the estuaries, as they were concentrated at the estuaries mouths in particular

 

This is a work in progress.