There are many reasons why cyclones benefit the environment, which includes cooling the seas and adding huge quantities of cooling rain to the hot and usually dry Pilbara. This research here shows that they are useful in distributing tropical corals. Who knew?/sarc …
Their worry is that cyclones may start moving south because of ‘global warming’! Seriously? Since Cyclone Alby crossed the coast near Perth in the seventies, when have any others actually done that? Or Cyclone Herby in the same era that affected Geraldton and mid-west districts, as late as May too?
Cyclones have neither increased or decreased over the decades, although higher rainfall was recorded in the same time frame.
Written by Rob Payne
New modelling suggests cyclones in WA’s north-west create conditions that allow coral larvae to rapidly travel distances between inland and mid-shelf reefs.Led by the Australian Institute of Marine Science, the findings help explain why less genetic variation exists between reefs in WA than for those separated by similar distances in the Great Barrier Reef.
“Despite greater geographical isolation, significant cyclone-induced currents have been shown to enhance connectivity between coastal and mid-shelf reefs in a way not seen on the Great Barrier Reef,” says co-author Dr Ben Radford.
“Inshore reefs in the Dampier region and mid-shelf reefs surrounding Barrow and Montebello Islands are separated in some cases by over 100km across the North West Shelf, and by a long-shore direction of the prevailing currents, which would usually provide a barrier to larval mixing.
“However, modelling suggests current patterns across the shelf may change dramatically before, during and after cyclones.”
Connectivity was modelled between reef zones for 1996 and 2001, when cyclones occurred around the time of coral spawning, and 2002, when no cyclones occurred and spawning took place under more typical wind patterns.
For cyclonic years, results suggest 63 to 86 per cent of coral larvae were transported between reef zones within six days—within the period when larvae are able to settle onto the substratum and enter the juvenile stage.
The 2002 non-cyclonic year showed no larval movement between reef zones; instead larvae remained in their respective regions resulting in reef self-seeding.
The models were created using OILMAP, a surface wind stress model, and GCOM3D, a three-dimensional hydrodynamic current model that simulates the effects of current and wind patterns on the dispersal of buoyant coral eggs.
Dr Radford says because WA has the highest frequency of cyclones in the Southern Hemisphere – an average of 3-4 per season – understanding how connectivity influences biodiversity patterns is critical for management and conservation, including how species populations within ecosystems might recover from disturbances that cause mortality.
They can also help interpret the effects of climate forecasts from the Intergovernmental Panel on Climate Change which predict less frequent but higher intensity cyclones for WA, with a more southerly range.
“If cyclones do migrate to a more southerly range, this could result in increased connection with the North West Shelf and neighbouring coral reef systems associated with the Ningaloo region,” Dr Radford says.
“Similarly, it could reduce the current connectivity patterns between some of the more isolated northerly coral reef systems of the North West Shelf.
“Understanding patterns of connectivity is vital now and for the future.”
The study was a collaboration between the Australian Institute of Marine Science, UWA Oceans Institute, UWA School of Earth and Environment and CSIRO.
Sea surface temperatures have barely changed in the last few decades, so forecasts from the IPCC and their models are 97% failures! They get paid for this?
[…]The last of the trend graphs on a zonal-mean basis is for the Indian Ocean, Figure 6. The models, basically, show way too much warming at most latitudes. […]
It doesn’t look like much change over the decades here either:
(12) Indian Ocean Sea Surface Temperature (SST) Anomalies
The oceans cover 70% of the world’s surface which means that is where any climate change would show first, not from temperatures gained from growing cities of concrete and steel! Or the fr****** models. I prefer to believe data and observations. Tisdale, again:
Monthly Global SST Anomalies
Update, In other ‘news’ from CO2 science:
Fighting Current Real-World Threats to the Well-Being of Corals: Rather than fantasizing over what to do about imagined future threats to coral reef ecosystems, a new study elucidates a current real-world problem and demonstrates a workable solution to it.
Microhabitats Enable Animals to Beat the Heat of Global Warming: A new study provides some real-world examples of the phenomenon.
Earthworms Working Overtime to Sequester Plant-Derived Carbon: In a long-term forest FACE study, the wiggly little creatures helped to sequester in the soil the extra carbon removed from the atmosphere by the rapidly-growing CO2-enriched trees.