Jennifer Marohasy
I was born in Darwin, and raised in the Tropics, knowing the sound of monsoon rains on a tin roof ā so loud, like a heard of buffalo galloping overhead. Always wondering, as I lay in bed when it would end, whether it would flood.
Caused by deep convection this is also how the Earth cools: driving energy from the Earth-ocean surface where it has accumulated to the upper atmosphere where it can be radiated to space as infra-red emissions. That is also the water cycle, and of course, water vapour is a greenhouse gas. Quite a bit was let off recently with cyclone Jasper and all the flooding.
The rainfall record for Kuranda is more than 120 year long, providing more than 4 weather cycles of information on rainfall in the catchment draining to Cairns, that recently suffered such terrible flooding. Especially the northern beaches, home to both family and friends. I phoned my sister to offer commiserations, and of course, she had to add that it was all so āunprecedented ā the rainfallā, she added.
I thought I would wait until the rainfall totals were in before making comment. And so it is with this new year that we have the rainfall totals for Kuranda, the longest records that I know of for that catchment, for the Barron River catchment.
Kuranda is a mountain village above Cairns ā beside the headwaters of the Barron River. Itās known for the Kuranda Scenic Railway, which winds its way down to Cairns through tropic rainforest dotted with spectacular palm trees growing aside waterfalls that vary from a trickle to a torrent depending, of course, on the rainfall.
As the story goes 1882 was another unprecedented year of heavy rain. It cut the supply routes from the mining towns beyond the mountains to the coastal settlements including Cairns. Legendary bushman Christie Palmerston was tasked to find a reliable supply route for a railway to link the rich mining area to the sea. And so, the Kuranda railway was built opening in 1891, and with an official Australian Bureau of Meteorology rainfall record from 1896.
This record does not extend back to 1882, but we can see that 1911 is the wettest year on record with nearly 5,000 millimeters (4,921) of rain, followed by 1979 (4,657) and most recently, this last December nearly 4,500 mm fell (4,417). It is the case that this December is the wettest on record, with the heaviest rains in 1979 falling in January, and in 1911 it was in April.
It is unfortunate that there is no continuous temperature record for Kuranda, in fact temperatures have never been measured at Kuranda, at least not by the Bureau. They were measured at the Cairns post office from 1890 to 1952, and of course, this record shows cooling of maximum temperatures from 1920 to 1940, as do maximum temperature records from around the world.
Yet, curiously, climate change catastrophists and leading sceptics alike tend to deny this cooling and go on and on, variously about the one degree C increase in temperatures through the twentieth century.
They also like to claim that it is impossible to forecast rainfall, even my colleagues at the IPA. Of course, if you strip every historical temperature record of all meaningful cycles (particularly the cooling from 1920 to 1940) then reliable rainfall forecasting does become impossible.
To be continued.
Shouldn’t that be Platform 9 Ā¾?
I like Kuranda, itās a friendly laid back artists village on the Atherton Tableland, sited where tropical moisture laden winds from the Pacific have first opportunity to dump their moisture after a substantial orthographic lift.
Given Kuranda is 17 degrees south, those winds blowing across thousands of miles of Pacific Ocean pack a lot of moisture.
āRains a lotā would be an understatement.
Spectacular scenery though.
Cairns city itself is mostly built on a swamp – shown by the large drainage canals which cross the area. However the canals were probably sized for the sugar cane plantations that were first built on the drained swamp. Now its mostly urban up to the foothills , and higher.
Its curious that the wet season Dec to April or so , shows a extremely high peaks over and above the monthly falls which show the average
“Now its mostly urban up to the foothills , and higher.”
Must do wonders for the run-off coefficient š
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Well jeeze will ya just look at dat? Da twentys an’ tirtys
had da highest temperatures. Don’t dat beat all?
The chart stops in the 1950s so…?
so what. !
Here’s one to 2017, showing 1923 or 1924 warmer than 2017
Why the Irish accent?
I live in South East QLD which has seen a huge deluge this past month. It is funny how so many people I talk to that previously had no interest in the weather patterns, make the comment “Isn’t this supposed to be a dry year because of that El NiƱo / La NiƱa / El NiƱa / La NiƱo thing”.
It is a good opportunity to remind them that there is still a lot we don’t know and our climate system is highly variable. Some comment that it must be due to climate change, which is ironic as the people pushing climate change would not predict such a wet El NiƱo period this year.
Lets just blame it all on climate change even if it does not fit the climate change story, life is much simpler then.
Diggs, please don’t WOKE El NiƱo, he’s a good boy. La NiƱa, on the other hand is a problem child, go ahead with the alphabet stuff.
It its even a better opportunity to remind them they are paying for the useless forecasts from the BOM who claim they know. They are paying for the forecasts/predictions these imbeciles make that are costing the country upward of a trillion dollars to fix the weather. Also claims he will stop the flooding by backing private enterprise to install more wind turbines.
Three months ago. BoM was predicting a dry, hot summer across Australia.
They also make the claim that their ACCESS climate model is “useful” Talk about false claims. If they were a private organisation they would be facing the ACCC for making false and misleading claims.
They will get to face an enquiry this year over their poor forecasting but it will be water under the bridge. The organisation needs to be set adrift from the government and learn to live by its forecasts.
Australia has one great advantage over countries in the Northern Hemisphere. Sunlight over the Southern Hemisphere is declining. The SH south of 40S is already cooling. The temperature across Australia is the same now as it was at the start of the satellite era. The BoM has wrung all it can out of homogenisation and instrument changes so is stuck with facing the reality that Australia will actually cool in coming decades. The CO2 botherers in the Northern Hemisphere have a less demanding task because the NH will continue to warm. The focus there has to be on ever increasing snowfall.
I remember that.
Is the Farmer’s Almanac still just as reliable as the BoM for seasonal outlooks?
It’s always far easier to blame climate change than actually think and work out what’s happening.
Which is what?
Nothing.
Oh.
I would say nothing out of the ordinary.
Everything in Al Gore’s ‘An Inconvenient Truth’ was down to change in land use and weather, NOT ‘climate change’. And that’s pretty much it – everything that’s been ignorantly attributed to ‘climate change’ can be proven to be change in land use or weather (often because it’s happened before in the same place).
But it’s a lot easier to jump on the latest bandwagon and proclaim ‘climate change’ rather than actually do any thinking, isn’t it? Especially for the climate enthusiasts who’ve never been particularly gifted in that department.
“They were measured at the Cairns post office from 1890 to 1952, and of course, this record shows cooling of maximum temperatures from 1920 to 1940.”
What the graph seems to show is that there was a significant and consistent warming of maximum temperatures which began around 1922 and ended around 1932.
There was then a general cooling of maximum temperatures from 1932 to the 1950’s, with just a few years of slightly higher maximum temperature than 1932.
Thanks Vincent. I agree that I could have been a bit more specific in my quoting of dates and characterisation of what happened over the period of the record for Cairns. In which case doesn’t the warming actually peak in 1923?
Isn’t this pattern, that I see in so many of the long TMax data sets for eastern Australia, similar to what was observed in the Arctic at about this time?
Hi Jennifer,
On reflection, I think I was nitpicking. Sorry!
The maximum temperature on the graph does appear to be about 1923, and the minimum after 1923 appears to be about 1942, so your statement would more precisely be:
āThey were measured at the Cairns post office from 1890 to 1952, and of course, this record shows cooling of maximum temperatures from 1923 to 1942ā
Here’s one from Cairns showing the peaks in the 1920 and 1930s still hold.
Is it still being claimed that Hunga Tonga is having no effect on rainfall?
Dunno. Such a massive eruption of water into the stratosphere is a first in recorded history. So we have to let the observational data sort out the good from bad theories. Per Feynman, that is actually how science is done.
First observed in recorded history, Rud. Who knows how often something like this has happened in the past?
That’s the problem with ALL of this climate change nonsense. No one knows what’s unprecedented and what isn’t.
Two supplemental comments to Jennās excellent rainfall post.
The reasons that very bad alarmist paper made my book draft edit cut was:
Kuranda, Saturday April 24, 1970. A bright sunny morning after a week’s worth of rain driving up the coast from Brisbane. To the station early enough we had our pick of seats on the rail motor going up to Kuranda. The ‘starboard side’ is the one with the views out towards the coast as you climb. Stoney Creek Falls? The train stopped and we could get out. We used up some 35mm film. The Barron Falls? Most of the water was being diverted to the hydroelectric plant. Kuranda Station itself – flowering plants all over. Walked into ‘town’, from memory (not in the trip log/diary), one pub and a couple of stores. A well worth-it trip.
(On Sunday, ANZAC Day, we were at the Curtain Fig Tree at midday, listening to the broadcast out of Canberra. Over fifty years later as I write about it today I’m tearing up.)
For me all I have to do is look at some of the worlds most spectacular geological topographical features and I donāt worry much about manās effect on the last 120 years. Now show me some of those old steam boat you all have down under there.
”Cairns Annual Mean Max temp”
It is highly likely that Richard Greene would say that graph shows human-caused global warming.
I reckon if you go a bit north or south you will find plenty of other high rainfall events.,
It is North Queensland coast!
It does rain quite heavily up there at times, y’know. š
Yeah, like Atherton 4 inches in an hour.
What an interesting meteorology place..
I went visiting lots and lots of Wundergrounds, there is a distinct and rigid pattern to them all.
(And James Cook haha University in middle of it all)
I am soooo fascinated by the twice daily cycle in the barometric pressure, how it peaks at around 08:30, falls to a minimum at 15:30 and then peaks again at around 22:30 then drops again to a minimum (not as low as the afternoon minimum) at 03:30
With a peak-to-peak swing of around 3mb
Which is not a lot BUT,
It is quite surreal
At a guess, that is the Emergent Phenomena Global Cloud Iris at work. The low pressure points are where thunderstorms are active far out to sea and the high pressure points are where the storms have cleared/spent themselves and ‘the system’ is recharging itself.
Certainly something to do with El Sol as he circulates round and round the globe.
Back on topic: What happened here is that Kuranda ‘won the lottery’
It was a very rare event created by the conjunction of myriad small events but especially by the geography of the place, = the Barron River valley/gorge
I’m used to that’ Odd weather things happen in the UK Lake District. They occur when a modest change in the prevailing conditions interacts with the geography and ‘Atmospheric Rivers’ and Pineapple Expresses become the order of the day.
Check out especially the ‘Cockermouth Flood’ of (2013 I think) also other Carlisle floods
Anyway, my attached picture and shonky scribblings describe it
The Normal Prevailing Wind at Kuranda Station is straight out of the east and pretty well straight off the ocean.
BUT, to get to Kuranda Town, the wind has to get over a 400m+ range of hills, putting the town in a rain-shadow
(This is *exactly* the Eden Valley in Cumbria/Lake District except the prevailing is a westerly)
Looking at the weather stations, the wind shifted (only slightly) to the south east during the rain event of week starting December 12th 2023
From my doodlings on the image, you can see the warm/wet winds off the ocean swung in directly over Cairns and were funnelled straight up the even narrowing Barron River Gorge which lies NW to SE without having to go over the mini-mountain range.
And poor little Kuranda is at the top of that gorge.
The geography wrung every last drop of water out of that airflow and Kuranda caught it.
Again, looking at the weather stations (there are a lot of them) it was a Very Local Event. You really did have to be in The Right Place at Exactly The Right Time.
The gorge and the rain itself triggered a Pineapple Express and it would have persisted as long as the wind had remained in the south east.
THAT was the oddity that did it: Why the prevailing wind stayed in a (just slightly) unusual direction nearly all week and pushed so much warm wet air up the Barron River Gorge.
It’s wet in the tropics
Dear Jennifer,
Throughout Australia rainfall is episodic (occurs as episodes of wet/dry years) and stochastic (random in terms of depth/duration and other features, including where it cares to fall).
It just happens that in 1974, from the 21 to 26 December (earlier than usual) Cyclone Tracy wrecked Darwin and not Cairns or Rockhampton, for instance. The cyclone history of towns along the West Australian coast, which have also been wrecked from time to time, shows similar hit-and-miss characteristics. Donāt forget also that Cyclone Sigma wrecked Cairns and other near-by towns and villages on 26-27 January 1896. There are some detailed eye-witness accounts of what happened that day in newspapers available from the National Libraryās Trove database.
It was known at least a week-out that Kuranda/Cairns was likely to get a drenching in late December, but not a month out, and that this time Darwin would not bear the brunt of it. Iām not sure whether it came ashore as a cyclone or a left-over rain depression, I suspect the latter. Peter Ridd did an excellent piece on this on ADH.TV (https://watch.adh.tv/featured-carousel/videos/peter-ridd-alexander-voltz-monday-18-december-2023).
The BoM has a marketing branch whose job it is to market weather-porn, but I donāt think an āinquiryā will change that, any more than the Royal Commission into the 2019-2020 bushfires changed anything.
Trying to tease depth/duration cycles out of episodic/stochastic data is the stuff of black magic. While, due to the El NiƱo southern oscillation, which is somewhat predictive of episodes of rainfall/no rainfall in Australia, there is such a thing as quasi-cycles or cycle-like occurrences of events, which is why ENSO is an oscillation, not a cycle.
Unlike ENSO and other climate shift-drivers (and there are a few that affect Australia), even when overlaid, cycles have properties of frequency and amplitude that make them predictable. It mostly rains in summer in the tropics, for example, and in winter across Victoria and Tasmania. So, there is a seasonal cycle regardless of whether it rains or not.
As well as rainfall depth/duration there is the added problem of which raingauge (which point on the landscape) will bear brunt. In the aftermath of Cyclone Tracey in 1974, most of eastern Australia copped a drenching. Spirits soared, however, from 1978 (plus or minus a year or two) the landscape dried, which led to the relatively short-duration but devastating 1980s drought.
Dust-storms occurred in Wagga Wagga that had not been seen since 1943-1947. In 1947/48 it rained like fury, and ended a dry epoch that commenced in the early part of the century. There was flooding everywhere, then reasonable seasons before tapering-off by 1960. Dry bush burns, so then there were bushfires up and down the east coast. I was in Katoomba just after the place virtually exploded, burn-out houses everywhere. But little mention of those disasters now.
A direct quote from my report on Cairns (Frontstory here: https://www.bomwatch.com.au/data-quality/climate-of-the-great-barrier-reef-queensland-climate-change-at-cairns-a-case-study/; full report here: https://www.bomwatch.com.au/wp-content/uploads/2020/02/Cairns-full-paper.pdf:
No Australian weather station sites have stayed the same and as is the case for many historic datasets, recent (28 July 2018) site summary metadata for the Cairns post office provides no useful insights about conditions that affected early observations. A file at the National Archives of Australia (NAA) (Barcode1 3092148) and photographs, show the post office was moved and replaced in 1907-08 then replaced by a two-storey building in 1928. According to Torok (1996)2 first correspondence with the Bureau was in April 1908; by 1924 the site was āhemmed in by buildingsā; it moved in December 1929 to a āslightly more open siteā then in 1943 observations transferred to the airport meteorological (met) office. Torok did not indicate when a Stevenson screen was first installed at the post office.
To assist your understanding the impact of site-changes on temperature data, I sent you the relevant part of Simon Torokās PhD thesis twice or more at times over the years. You could have read his notes about the Cairns Post Office. I spent days also at the National Library and National Archives of Australia doing in-depth research into what happened at the airport.
From my report: āMetadata incorrectly specifies location of the original aerodrome site near the 1939 Aeradio office and ignored the move to the mounded-site near the centre of the airport in 1966. Also ignored is that by September 1983 the site was moved again out of the way of a new taxiway. During construction when neither site was operational, aerial photographs show a fourth site was established on reclaimed land near the location of the current automatic weather station. Data from that site either in-filled the record or were used to adjust for the 1983 relocation. The highly significant step-change in 1986 plausibly marked when in-filling or adjustments ceasedā.
It is a mistake to just join the dots. The information you needed in order to understand the temperature profile at Cairns was available at http://www.bomwatch.com.au in January 2020.
It is no secret that moving weather stations, closing them in with buildings, putting them on mounds then shifting them out of the way of new developments at the airport, then installing satellite gear nearby affected the data. There was no warm (or cool) period at Cairns, at least as far the climate was concerned. Also, accounting for those effects leaves no cycle or trend or anything.
Cairns is just another century-long dataset that shows that the climate has not warmed or changed, and therefore, that it is unlikely to warm or change in the future.
References:
[1] Search barcodes at: http://soda.naa.gov.au/barcode/ (possibly now out of date)
[2] Torok S.J. 1996. The development of a high quality historical temperature data base for Australia. PhD Thesis, School of Earth Sciences, Faculty of Science, The University of Melbourne, Australia. p. 243 (of 547 pp).
Yours sincerely,
Dr Bill Johnston
http://www.bomwatch.com.au
I said in my reply: So, there is a seasonal cycle regardless of whether it rains or not. To correct the record, what I meant was: there is a seasonal cycle regardless of how much rain falls.
Daily and monthly rainfall is strongly long-tailed, meaning that while rainfall cannot be less than zero, upper ranges can always be exceeded, which is why it forms a log-normal distribution. Percentiles of daily/monthly values can provide exceedence estimates, as can probability density estimations.
For a particular raingauge, extremes are extremely rare probably on the scale of 1 in 100s of years. Regionally though, averaged across gauges, it would be much less.
Over to you,
All the best,
Dr Bill Johnston
http://www.bomwatch.com
Dear Jennifer,
On rainfall at Kuranda (1881 to 2019) and Barron River discharge
In 2020 I undertook a detailed study of rainfall-discharge relationships along the Barron River, sourcing all the data I could find. I did it gratis in my own time, with the ultimate aim of producing a report, then publishing it in a reputable Journal. Along the way, it became clear that it would never be accepted, mainly because it set out to refute many of the claims being made about nutrient discharge to the Great Barrier Reef Lagoon, so I set it aside unfinished. However here are some highlights:
The Barron River drains a highly productive wet-tropics catchment of about 2,178 km2 in northeastern Queensland and discharges into the Great Barrier Reef Lagoon’s Trinity Bay beside Cairns International Airport. Although said to be one of the most heavily utilised and impacted-on of all Queensland’s wet-tropics streams, over two-thirds of its area remains forested. A brief description in Wikipedia (https://en.wikipedia.org/wiki/ Barron_River_(Queensland)) notes the river is the sole source of sand for the beaches to the north of Cairns, thus sustained changes in rates of sediment delivery to mangrove communities around its delta and the Reef Lagoon may have unintended consequences for ecosystems further along the coast and possibly for coral cays including the popular tourist destination, Green Island.
The investigation focuses on the work by Cogle et al. (2000), which links sparse in-stream nutrient load datasets to land-use impacts using a modelling framework or decision support system (WinCMSS). Of particular concern is that if data don’t reflect paddock-scale nutrient and sediment generation processes, the model is unlikely to provide realistic sediment and nutrient discharge estimates.
On the input-side of the water balance, rainfall measured under cyclonic conditions by the 5-1/2 inch raingauge situated on the platform of the Kuranda railway station may not be accurate ā¦ snip.
Exploratory data analysis showed that rainfall is the impulse variable; that it is highly seasonal and due to runs of dry and moist years, the climate is non-stationary in the long-term. A relatively low rainfall epoch of ~50 years duration has occurred in the past and therefore may occur in the future. Runs of years when rainfall is benign or above average have not continued beyond about 20 years but because the climate is unpredictable and chaotic, predictions about the future are highly uncertain. There is no evidence in Kurandaās (and other centresā daily records that the frequency of daily rain falls (>25 and >100 mm/wet day) has increased in recent time. Therefore, runoff/river discharge changes are due to more or less rain falling; not changes in the intensity of rainfall events.
Both rainfall and dependent hydrological responses are dominated by infrequent high-impact events and overwhelmingly high discharges can occur from wet catchments receiving additional heavy rain. Relatively few events are responsible for the most of the discharge measured at individual stream and river-gauges [Typically, the 10 highest events in 50 years, account for some 20% of total discharge.] Throughout its length, the Barron River accumulates flow and aggregating data through the system is unlikely to provide unbiased end-of-system estimates of nutrient and sediment washoff. There must also be an enormous bed-load periodically ejected by extreme events for which no data exists.
Both rainfall and discharge data are highly skewed; within years by the seasonal signal and between years by the dominance of extreme events. Arithmetic averages therefore donāt usefully describe discharge behaviour across the catchment and its tributaries. While the seasonal signal can be handled as a categorical variable (Monthfactor) in multiple linear regression, long-tailed data are usually analysed by taking logarithms, which reduces the data range and causes the distribution to be symmetrical (i.e. more likely to be normally distributed and therefore amenable to parametric statistical analysis).
Contributing to the problem of reliance on sparse data and models, is that rounded values of exports from catchments in tonnes or kg/ha are derived by multiplying together very small and very large numbers, without considering if derived values are realistic. For instance, a point estimate of solutes or suspended particles, measured in mg/L (= 1 part per million or 1 g/ML) multiplied by an exponentially higher discharge estimate (ML/day or per month) incurs exceptionally high uncertainties.
For data whose distributions are naturally highly skewed, the question arises: what constitutes a realistic average of a small quantity measured at a gauging site opportunistically during a flow event, when the sample from which it was derived may not be drawn from a homogeneous water column? Considering that the water level at the Flaggy Creek Stock Yards gauge (a lower-Barron River tributary) varies between zero and 3 to 7 meters depth over a 12-month period, itās unlikely that a near-surface 1-litre sample taken in turbulent water moving past at rates of 300 to 500 m3/second is representative of either the sampled water column or the 150-km2 catchment above the gauge.
It is consequential also that concentrations of total nitrogen and phosphorous (TN and TP), stream discharge and total suspended solids (TSS) calculated as averages are factors-higher than if calculated as medians and geometric means. For instance, the nitrogen loss rate calculated by multiplying mean total nitrogen concentration with mean discharge is 32.0 kgN/yr, while that calculated by multiplying respective medians is 7.1 kgN/yr, which is a 4-fold difference. Arithmetic means are strongly influenced by infrequent upper-range values, which donāt reflect the long-term behaviour of catchments or the processes that result in runoff delivery to sampled streams.
Complicating relationships between land use, runoff and nutrient and particulate washoff is that the long-term climate of the Great Barrier Reef catchment is non-stationary (Figure attached). Periods when rainfall is relatively high such as from 1994 are conducive to higher-than-average rates of stream discharge, soil erosion and washoff than periods when rainfall is near average or relatively low such as between 1914 and 1962.
Reference:
Cogle, A. L., Langford, P. A., Kistle, S. E., Ryan, T. J., McDougall, A. E., Russell, D. J., & Best, E. (2000). Natural Resources of the Barron River Catchment 2-Water Quality, land use and land management interactions. Department of Primary Industries, Brisbane.
Yours sincerely,
Dr Bill Johnston
http://www.bomwatch.com.au