‘The Millennium Drought was far from an exceptional event for eastern Australia during the past thousand years …’
FRISCO — Even without the added factor of global warming, eastern Australia is susceptible to climate extremes, including long-lasting droughts that could put a huge strain on water storage and delivery systems.
Global warming, coal port dredging seen as key threats
FRISCO — Leading Australian scientists said this week that the government’s business-as-usual plan for the Great Barrier Reef won’t prevent its decline.
While acknowledging a few positive steps in the plan, the Australian Academy of Scientists said the proposal “fails to effectively address any of the key pressures on the reef including climate change, poor water quality, coastal development and fishing.”
And, as is often the case with planning efforts in the U.S., the Australian government’s vision for the reef also doesn’t acknowledge the cumulative impacts that intensify pressure on one of the world’s most diverse marine ecosystems.
Outdoor air pollution causes 3.7 million deaths each year
FRISCO — A new study by an Australian researcher underscores the fact that, when it comes to air pollution, there are no safe levels.
The research by Adrian Barnett, of the Queensland University of Technology, shows that the Australian government’s standards for key outdoor air pollutants are misleading, as many authorities wrongly assume them to be ‘safe’ thresholds for health.
FRISCO — Along with the stress of global warming and the disappearance of reef-grazing fish, corals are also beset by the increasing pace of coastal development — specifically dredging — which can increase the frequency of diseases affecting corals.
Fish rely on swimming for almost all activities necessary for survival, including hunting for food and finding mates, said Dr, Jacob Johansen, explaining that their research found that global warming may reduce the swimming ability of many fish species, and “have major impacts on their ability to grow and reproduce.” Continue reading “Are reef fish slowing down as oceans warm up?”→
Satellite tracking helps researcher develop a formula to predict swell decay
By Summit Voice
FRISCO — Surfers have long tracked swells across thousands of miles of open ocean to try and predict when the best waves might hit their local beach, and new research by an Australian National University professor may help fine-tune those forecasts.
“Ocean cargo shipping, offshore oil and gas production, and even recreational activities such as surfing, are all dependent on wave action,” said Ian Young, vice-chancellor of ANU. “It is therefore critical that we are able to predict swell.”
Young, who is affiliated with the Research School of Earth Sciences, was interested in determining the rate at which ocean swells decay as they travel across the ocean, so he tracked them with orbiting satellites. The results showed that the decay of the swell depends on how steep the wave actually is.
“Steep waves decay very quickly. However, typical swell is not very steep and can travel across oceanic basins with only a relatively small loss of energy,” he said.
Over 200 individual cases were tracked, making this study the first to provide such comprehensive data of this decay.
“What we were able to do is track the swell from the satellite as it moved from the south to the north, some 1,400 kilometres. We only chose cases where there was no wind so that we could be confident that all we were measuring was the swell decay … We can take these results and put them into a mathematical formula that can be put straight into computer models used by national weather bureaus
“This will increase our ability to better predict wave action. As 70 per cent of the world’s oceans are dominated by swell, it’s extremely important to be able to predict them accurately,” he said.
It is estimated that 75 per cent of waves across the world are not actually generated by local winds. Instead, they are driven by distant storms which propagate as swell.
“For most of the Indian, Pacific and South Atlantic oceans, it is actually the weather in the Southern Ocean thousands of kilometres away that dominates the wave conditions … The Southern Ocean is dominated by big low pressure systems that move across it year round. These systems generate waves that then grow and can travel tens of thousands of kilometres from where they were actually formed, to crash on a beach in Australia.”