Last night I was very briefly on Sky Television, and we were reminded by Andrew Bolt that Professor Tim Flannery once said the dams would never fill again. Back in 2009 we were told to expect drought as the new norm here in Australia because of climate change.
That was when we had El Niño drought conditions, meaning the trade winds were weak and more rain fell on the ocean than could make it to the Australian mainland. But, of course, the conditions changed – as they always do, because there are cycles – and what is known as a La Niña developed. It was a very strong La Niña by the end of 2010 with an SOI value of +27.1 for December.
The dams along the east coast of Australia did fill suddenly with the change in the cycle to one of wet from one of dry. To the extent that the city of Brisbane was flooded – with more than 20,000 homes inundated – after SEQ Water was forced to make emergency releases of water from Wivenhoe dam in January 2011! SEQ Water had mistakenly kept the dam full of water through December, even though the dam was built for flood mitigation – to catch the water should there be torrential rain. There was no reason for Brisbane to have flooded, except they got the seasonal forecast so wrong along with the dam management. They weren’t thinking in terms of cycles – they never do.
Wivenhoe dam was built following the terrible 1974 inundation of Brisbane when more than 6,000 homes were flooded following torrential rains following Cyclone Wanda. That was also a La Niña year with the SOI index at +31.6 in November 1973.
The SOI index is the difference in air pressure between Tahiti and Darwin.
When there are strong pressure gradients, we have stronger than usual trade winds drawing moist air from the Pacific Ocean all the way to the Australian mainland. When the winds are not so strong, and especially during El Niño conditions when they are weak, it is more likely to rain over the ocean with the storm clouds and cyclones not making it as far as the Australian east coast. Then we risk drought here in Australia.
We can see cycles of La Niña and El Niño in the air pressure data that goes right back to 1876 as measured between Darwin and Tahiti. Indeed, Australia is a land of drought or flooding rains because of these cycles.
Except that David Jones, and other activists, hold such key positions at the Australian Bureau of Meteorology and have for so long, and they refuse to acknowledge the strength of the cycles because they are so wedded to the theory of catastrophic climate change and the idea that there are tipping points when there are just cycles. They brief Tim Flannery who is really just one of the useful idiots. Andrew Bolt shouldn’t really be so upset by him! It is the Bureau that has the potential to deliver much better forecasts, but that would require them to recognise there are cycles that persist and give up on the notion of a climate catastrophe.
John Abbot and I went to the Bureau to talk with them, specifically with Oscar Alves, back in August 2011 about the potential of Artificial Neural Networks (a form of machine learning/artificial intelligence) for more reliable seasonal rainfall forecasting. We used the SOI index as a key input, and have detailed our technique in a series of published papers.
The feature photograph at the very top of this blog post was taken outside our unit in St Lucia Brisbane after the apartment block was flooded in January 2011. It was quite a job, the cleanup.
>” … cycles of La Niña and El Niño in the air pressure data that goes right back to 1876 as measured between Darwin and Tahiti. ”
That Jennifer was able to outline the air pressure gradient factor on a popular TV spot is grand news.
Bob Carter (sadly deceased, much missed) when active as the Geology Professor with the James Cook Uni published a number of papers (yes, peer reviewed to avoid ad homs) detailing the results of ocean bed drill cores off the coasts of both South America, mainly Peru, and east coast Australia. Bob had been the prime geoscientist on a number of those drill programs.
The sediments from the cores are quite easily logged for ENSO oscillations, as inland wet periods deposit thick sediment layers offshore as swollen rivers release the sediment into the oceans. Similarly, dry periods cause thinned-out sediment deposits.
From this research and contributory mapping, ENSO oscillations have been mapped as occurring for at least the previous 11,000 years.
These results and published papers are quite easily found on search for those who wish to understand this in more detail. I regard Jennifer’s weblog here as not perhaps well suited to reams of academic references.
spangled drongo says
Yes Jen, that 2011 flooding in Brisbane would never have happened if those responsible had even bothered to pay attention to the levels. I was camped at Wivenhoe at the time and saw the levels getting dangerously close to the earth fuses which are designed to wash out and save all the expensive infrastructure but cause huge earth-erosion and flooding. I tried to contact the authorities but there was no one home. When they finally saw what was about to happen with this 200% capacity they had to dump water in huge amounts thus causing all that destruction that this great reservoir was specifically designed to prevent.
La Ninas have always been a source of excess cloud cover, rainfall, wind and general cooling and since the ’70s we, luckily, have not seen so many of them.
spangled drongo says
Jen and ianl, I wonder if ENSO could be the culprit? Not many La Ninas since the panic started. And just look at the lack of el Ninos during the “global cooling” panic period :
Bill hankin says
Jen can I share this on BOM WEATHER WATCH ?
The truly “sick” part of the 2012 BizVegas floods is that the Wivenhoe, like the Somerset, before it, was built as FLOOD-MITIGATION DAM, not a “reservoir”.
Furthermore, when they talked about “capacity”, “100%” does NOT mean “full to the brim”, but it’s nominal MAXIMUM holding level. That those clowns were playing with the live of tens of thousands seems to have been flushed down the memory hole.
There were several other WATER_STORAGE dams proposed for upgrading or construction in South-East Queensland, but the eco-loons and their parliamentary playthings stopped all that.
The final twist in the Wivenhoe tale is that because of where in the Brisbane valley it is sited, it HAD to be built as a clay-cored rock wall. The Brisbane valley is home to the occasional minor earthquake, because of a large, underlying fault.
So: the wall had to be “flexible”. Fair enough. However, the clay in the core of the wall is what actually holds the water back. The big rocks are to steady the clay. This is not just any old clay, but stuff called Smectite, which expands when wet. The catch is that it takes time to do this on a large scale. It also shrinks and cracks when NOT in contact with water.
If the dam level has been low for an extended time, there will be a LOT of cracks in the clay. HOWEVER, WHEN the rains come, (contra Flummery), if the water level rises too quickly, it will start to push through the cracks and erode them wider. Then, there will be water on the abundantly cracked “dry” side of the core.
IF the “leakage” rate exceeds the ability of the Smectite core to “seal”, there WILL be a LOT of water escaping. IF that flow rate is big enough, it WILL start displacing the rocks. This is NOT a good thing.
The “water-politics” types were saving us from “drought” whilst simultaneously risking much of Brisbane ending up on the bottom of Moreton Bay.
Then, there was the utter bewilderment of the “experts” when other tributaries of the Brisbane that enter BELOW the dam went feral.
I suspect the more competent among the hydrologists and civil engineers were filing documents with their lawyers about all this.
Most people cannot comprehend the scale of flooding that can and HAS occurred in Brisbane. In the 1890s, a monstrous “cloudburst” in the headwaters of the Stanley River did spectacular damage. Eyewitness reports from just south of where the Somerset dam was finally built, refer to a “wall of water, fifty feet high” traveling at unbelievable speed downstream. When that surge tore into metropolitan Brisbane, it erased major bridges and killed dozens. Some idea of the power involve can be seen in the story of the Queensland navy ship, “Paluma”. This was unceremoniously ripped from its moorings and dumped in the middle of the Brisbane Botanical Gardens. Thus half of the Qld Navy was “out of service”. Whilst the engineers were trying to work out what to do, a very short time later, a SECOND flood came through and tossed the 100ft steel ship back into the river. And there was much rejoicing.
Hence the origins of the Somerset Dam on the Stanly branch. BTW it was not finally in service until 1959; two world wars and the usual bureaucratic torpor saw to that.
I am NOT a hydrologist, a rock doctor or a civil engineer, I was merely here for the events of 1974 and 2012.
Ian Thomson says
Gidday Bruce, fascinating stuff. Love the bit about the ship.
AAAARRRGH! 2011, NOT 2012!
However, for the enthusiast, there is this handy history:
A maritime history update:
Details noted and filed.
Don Gaddes says
Prevailing weather moves from West to East, (Axial Spin.)
The Earth is covered by more than 70 percent water – thus, evaporation and precipitation is the ‘default’ state.
There is a hierarchy of Solar-induced Orbital Dry Cycles, that orbit the planet from East to West, (retrograde to Axial Spin, ) and affect the water molecules in the upper atmosphere, via the bombardment of Solar Particles, (see Metal/Steam Reaction.) These Dry Cycles have an exact longitudinally-based Terrestrial Footprint and orbit the planet at 15 degrees longitude per 30 day/night interval, (Earth/Solar Month.) Each subsequent Dry Cycle begins thirty degrees of longitude to the West of its associate predecessor.
Currently, there are NO valid ‘average’ temperature or precipitation readings, from any BoM world-wide, because of the orbital nature of these Cycles and the fact that these Dry Cycle Hierarchies only repeat every 81 Years.
There are NO decadal oscillations, (ENSO.) The process operates on Base 12 Maths.
There are always 360 Day/Night Intervals per Earth/Solar Year.
The Earth moves through 30 degrees of Solar Orbit every Earth/Solar Month. (12 X 30 = 360 degrees. For more details;
“Global average” temperatures are a crock.
Hold a block of dry ice (yucky CO2) in one hand and shove the other into a working blacksmith’s forge.
What is your average temperature? Who cares?
Unless the EXACT same, annually certified thermometer has been used, in exactly the same “screen”, in exactly the same physical environment, and at the exact same times of day, from the very start, comparisons of readings from just that single station for a century or so, are dubious, at best. People hyperventilating about a tenth of a degree “rise” are mad or malicious. A tenth of a degree over a decade? may be worth watching. A tenth of a degree over a century? Really? That is buried in the noise-floor of system error.
How many “legacy stations are now in urban heat island? How many with the same name are actually in “new” locations possibly kilometers away and possibly even a at a different altitude.
How much “creativity” has been going on, out in the field, let alone on the number crunching departments?
The “fear-porn” is subverting actual dispassionate science. This will not end well.
Geoffrey Williams says
I wish our politicians and lawmakers in Australia would take more notice of real scientists like yourself Jennifer. Historical data and empirical evidence should be given more consideration without the fearmongering of the academic left and the media shouting an existential crisis. We need to plan for real solutions to future weather events and where possible build infrastructures to meet mitigate disasters.
Frances Lilian Wellington says
Hi Jennifer, nothing would please me more than for your forecasting approach to be adopted at BOM. Why? Because I recall the week before the 2011 flood warning was given. As a postie outdoors long days every day I could ‘sense’ it building up… yet no public warning… I was warning everyone though, and then (finally!) BOM made it public. “About bloody time!” I said. Had they announced a flood was coming 5-7 days earlier (when I knew it for certain) then the citizens would have been better able to prepare.
That lax attitude was an ‘eye opener’ for me, as it became obvious that BOM held off warning people until it became too bloody obvious! Perhaps they announced it late to heighten the ‘shock value’ of so called ‘climate change’ blah blah blah.
I’m sure if you were the boss there such bullshittery would be a thing of the past.
Richard Bennett says
Jennifer talks about science whilst BOM still operate on pre-science principles which belong to the stone age.
Don Gaddes says
Alex S. Gaddes identified the Dry Cycle Hierarchies in his work ‘Tomorrow’s Weather’ (1990) and associated them with what he termed his Ratios Principle.
The two Dry Cycles most associated with global short-term weather patterns, he named as a Regional Dry Cycle every 6 and 3/4 Years, (81 months) – and a minor Dry Cycle every 2 and 1/4 Years, (27 months.) These Dry Cycles occur in tandem, from different Start Longitudes. Three Minor Cycles of twelve month duration and eight month terrestrial footprint, occur in tandem with One Regional Cycle of twenty-four month duration and sixteen month terrestrial footprint. Thus, for the Minor Cycles we have 27 months X three equals 81 months. For the Regional Cycles, we have a duration of 81 months.
If each new manifestation of these orbital cycles migrate subsequently by thirty degrees of longitude Westward, we have a 360 degree repeat sequence of 81 months times twelve. Thus, 81 months to 81 Years = a Ratio of 1:12.
It may be noted that the Earth/Solar Orbital Calendar replaces the Gregorian Calendar in these calculations.
Bernie Gittelson says
Thanks for linking to your publications, the work on natural cycles is very interesting, sometimes things hide in plain sight. I have used periodic functions back when we didnt have such computational power.
You should be brought in to clean up the BOM.