Feeling hot: Southeast Australia is in the grip of a record breaking drought, and now a heatwave too.
Credit: iStockphoto
SYDNEY: An Indian Ocean weather system may be causing, and prolonging, severe droughts in southeast Australia, according to a new study.
Scientists from the University of New South Wales (UNSW), in Sydney, have found evidence that El Niño, which is associated with bringing warm and dry conditions, and La Niña, with bringing cooler, wetter conditions, actually have little influence on the ongoing drought.
The current drought, which began in 1992, is the longest and more severe known since records began in the 19th century. The same study has linked the World War II drought (1937-1945) and the Federation Drought (1895-1902) to the weather system, known as the Indian Ocean Dipole.
Dry winds
That system determines if moisture-bearing winds or dry winds are carried across the southern half of Australia, and a continuous period of dry winds could be the cause of our current drought, say the scientists in a study to be published in the journal Geophysical Research Letters.
The Indian Ocean Dipole (IOD), is an oscillating weather system where warm and cool surface waters at either side of the Indian Ocean periodically swap places (see, Coral growth rings point to bad weather ahead).
This cycle involves a negative phase, a positive phase and a neutral position. In the negative phase, the Indian Ocean waters are cool, with warmer waters to the north in the Timor Sea. The westerly winds pick up moisture from the cool water and carry it across the land, so southeast Australia experiences moist, warm air and rainfall.
In the positive phase, the patterns are reversed. Less moisture is picked up from the warmer waters, which brings weak, dry winds and much less rainfall.
Losing streak
The new study reports that the IOD has only seen positive and neutral phases now for over 15 years.
"There hasn't been a single negative phase since 1992, and this is the longest no negative phase event we have on record" said Caroline Ummenhofer, a climate change scientist and lead author of the study. "All you're left with is dry events."
The last three years haven't seen a single neutral phase either, with a record breaking three positive phases in a row.
"If the Indian Ocean Dipole events do follow the trend of seeing more positive events and less negative ones, this is a terrible piece of information for the Murray Darling Basin," said co-author Matthew England. "This Basin is under a lot of stress at the moment with drought, and it needs replenishment with more negative Indian Ocean Dipole events."
EL NINO OR NOT EL NINO, THATS NOT THE QUESTION.
The REAL QUESTION is not in finding the cause but in finding a way to "live with" our anwsers. Whats the point in always knowing how "this" works or exactly what causes "that" when we don't seem to change the way we live to suit.
A Drought is a Drought is a Drought.
El Nino, La Nina or night-time fan fairies, we do not build our lives, communities, cities or our future around the answers we find. We live on the driest continent on Earth. With the knowledge we have we know we will get less continual rain patterns but more selective storms/downpours and the Governments answer the problem with rain tanks, bigger dams and water restrictions instead of recycling. My water carrier is aiming for 12% in the distant future( up from 7%)of recycled water when we know it is possible for most of the water we use to be recycled ( at least 85%).
We know that Global Warming/Climate change (man made or natural cycle of planet) is real. Something is happening and it's been changing noticably since late 70's. We all know of the little things that we can do to help the planet and enviroment one-way or another then you find it all blown out the window in the course of our days at work. Depending on the industy you work in. (I'm a trades assistant in an engineering and machining shop that works in connection with the mining and coal producing companies. Don't get me wrong, this is a good company and full of good blokes but couldn't this still be a good company with the same good blokes if it was engineering and machining shop for solar,wind etc companies).
We spend most of our awake life at work, where really we can't make that big a difference. And we all know that it is because of business that the world turns. wouldn't it be nice if the world continued to turn because of the people,s needs rather than businesses wants.
I don't know how hard it it would be to change our path towards a better future but i know it is worth giving it a go. If we as a people already know the problems we have and some of the one's we face then half of our battle is won.
It only takes 200 members to start a new political party.
We all know what future is available just through reading COSMOS, but with the current political parties can you ever see your kids living in it. We have problems with Health, Policing, Education, Jobs, Families, all of which relate to the people/communities, as well as Water and the Climate. And if these don't relate to the people then i don't know what does. Lets talk more on answers and show the people a future worth making. Our answers will show where the jobs of the future will be.
Craig.
Drought
I don't believe you
drought
Its GLOBAL WARMING
Drought
Thats very interesting