There is some major messing with data going on.
What would you say if you knew that the official Perth thermometer was accurate at recording minimums for most of time in October in the eighties, but 0.7°C too warm all of December, and 1.2°C too cool in January? Bizarrely that same thermometer was back to being too warm in February! Try to imagine what situation could affect that thermometer, and require post hoc corrections of this “monthly” nature. Then imagine what could make that same pattern happen year after year. All those weather reports we listened to in Perth in 1984 were wrong (apparently). And this bizarre calendar of corrections is turning up all over Australia.
Bob Fernley-Jones has looked closely at all the adjustments done to achieve the wonderful homogenized ACORN data, as compared to the theoretically “raw” records listed in Climate Data Online (CDO) on the BOM website. He can’t know what the BOM did (since they won’t tell anyone), but he knows the outcome of their homogenization. He was shocked when he noticed a strange square-wave pattern repeating year after year; he was astonished that there were corrections calendar month by calendar month, up and down, switching [...]
Two out of three Australians live in our capital cities where the longest and best resourced temperature records would be found. These are the places where the weather reports matter to the most people on a daily basis — and where headlines about records and trends will be widely discussed. But these are also the sites which have been affected by the growth of concrete and skyscrapers, and potentially have the largest urban heat island (UHI) effect, so might need the largest adjustments.
Bob Fernley-Jones has been going through the BOM records for six of Australia’s state capitals, looking at the original raw data (at least, as is recorded in the BOM’s climate data online, called CDO). Bob compares the new “corrected” dataset called ACORN for these locations — that’s the all new marvelous adjusted data. He finds many step changes that can’t be explained by known site moves or the UHI effect. Many step changes occur in either minima or maxima, but not in both at the same time, which is also odd. As we already know, the adjustments usually cool the past — especially the minima (see all the blue lines on graphs below [...]
Let’s play the Heatwaves PR game. If CO2 had an effect we’d see a significant increase in the rate of global warming over the decades since WWII, the models would work, and climate scientists would be able to predict our climate. Since none of that is true, those with a political agenda have to clutch at noisy but marketable extremes instead. Apparently even a half-true, noisy, non-causal link is good enough for post-modern scientists.
Heatwaves are perfect for generating scientific sounding fear, but not so useful for generating actual scientific knowledge. There are an infinity of ways to measure them. They can last 3 days – 160 days, and be cut off at any number from 35 – 40C, or at some percentile outlier. They can be measured one town at a time, or on a regional or state-wide level. The permutations are rich with headline scoring possibilities. And in the end, on a long warming trend that started 300 years ago, it is obvious, inevitable, and predictable that we should score more now. What’s surprising is how often we don’t.
On ABC radio before Easter, Dr Vertessy, Director and CEO of the Bureau of Meteorology, claimed that we are seeing [...]
UPDATE: Data for Middle Percy Island has disappeared from the BOM site, but Jennifer Marohasy kept a copy. (I’m sure the BOM will be grateful!) The Courier Mail has an article quoting Jennifer.
The facts on Cyclone Marcia: the top sustained wind speed was 156 km and the strongest gust 208 km/hr. These were recorded on Middle Percy Island in the direct path before it hit land and apparently rapidly slowed. The minimum pressure recorded after landfall was 975Hpa. BOM and the media reported a “Cat-5″ cyclone with winds of 295 km/hr. To qualify as a Cat 5, windspeeds need be over 280km/hr. The UN GDACS alerts page estimated the cyclone as a Cat 3.
The damage toll so far is no deaths (the most important thing), but 1,500 houses were damaged and 100 families left homeless. It was a compact storm, meaning windspeeds drop away quickly with every kilometer from the eye, so the maps and locations of the storm and the instruments matter. See the maps below — the eye did pass over some met-sites, but made landfall on an unpopulated beach with no wind instruments. It slowed quickly thereafter. The 295 km/hr wind speed was [...]
When it comes to our rare high-quality historic records, and the real long term trends of Australian weather, the silence is striking. There are some excellent historical records of long term temperature data from the late 1800s in Australia, which lie underused and largely ignored by the BOM.
For the BOM, history almost appears to start in 1910, yet the modern type of Stevenson screen thermometer was installed across Australia starting as early as 1884 in Adelaide. Most stations in Queensland were converted as long ago as 1889 and in South Australia by 1892. Though states like NSW and Victoria were delayed until 1908.
Here’s a photo of the ones in Brisbane in 1890.
Brisbane was recording temperatures with modern Stevenson screens in 1890, as were some other stations, but the BOM often ignores these long records.
The BOM don’t often mention all their older temperature data. They argue that all the recordings then were not taken with standardized equipment. The BOM prefers to start long term graphs and trends from 1910 (except when they start in 1950 or 1970, or 1993).
The BOM was set up in 1908. Before that there were Stevenson screens going in [...]
Heatwaves are a wonderful headline generator. That’s because the term sounds scary, yet the “wave” itself is undefined. A hundred different types of heatwave are theoretically possible, but they all sound the same in a headline. It means an activist team could pick and choose the particular one that scores a “record”. Heatwaves can be 3, 4, 5, 7 or 10 days. They can be measured by town, city, state or national data and they are can be above 35, 37, 40 degrees or… pick a number. A heatwave can be measured as days above some percentile of average. That means a few warm days in a cold town can be defined as a heatwave.
Geoff Sherrington, drawing no dollars from the taxpayer, takes a simple and obvious approach, and looks at 5 capital cities with the BOM raw and adjusted ACORN data. He considered 4, 5, and 6 day heatwaves to see if there was a trend. With 5 cites, 2 data types, 3 lengths of heatwave, Sherrington created 30 graphs. After testing all those different combinations of heatwaves, there were only three graphs out of 30 that showed an increasing trend. Over half of the heatwave graphs showed [...]
What really happened in 1878?
The raw data at Nobby’s near Newcastle (graphed below) shows monster heat in 1878, 1879, and 1883 — far hotter than modern times. Its unlikely that it was recorded with modern equipment, so it’s hard to compare. Was it really hotter? We don’t know when the Stevenson screen was installed. I went hunting through our wonderful historic Trove archive of old newspaper records. It doesn’t help us make any accurate comparisons, or even tell us about annual averages, but there is a remarkable story of exceptional heat and dryness in January 1877 that few Australians know. Let’s revisit the times of forgotten people who lived when CO2 was perfect and the climate was ideal.
How hot were the 1800s in Australia? My favorite quote is about the miners near Braidwood (in the mountains between Canberra and the coast). It reached 108F but look at the cultural norms:
“Years ago in the valley the miners always ‘knocked off’ if the thermometer registered 112 degrees (44.4C) in the shade, but times and wages are changed now, and the poor men are willing, to work on days like last Friday 18.1.78″ (see the Freeman’s Journal link [...]
Australia is one of the most stable land masses on the planet, and has more gauges than anywhere else in the southern hemisphere, so it’s very useful for sea-level measurements. It also had a couple of rare continuous long records “… the two longest sea-level records in the southern hemisphere, Sydney Fort Denison from 1886 and Fremantle from 1897″ .
A new paper by White et al, concludes that Australian sea level rises are similar to global measurements (so not a bad proxy for the world), and that during times when CO2 levels were much lower — like before World War II, sea levels were rising at the same speed (or possibly faster) than they are today.
A generalized additive model of Australia’s two longest records (Fremantle and Sydney) reveals the presence of both linear and non-linear long-term sea-level trends, with both records showing larger rates of rise between 1920 and 1950, relatively stable mean sea levels between 1960 and 1990 and an increased rate of rise from the early 1990s.
Does a “larger rate of rise” mean larger than today, or larger than average — I think, given the error margins, that we could only be sure it [...]
Dennis Jensen, M.P. in the Australian Parliament, made a formal parliamentary request for an audit of the BOM and CSIRO data handling processes.
This is an excellent request, something Australia desperately needs. Good data on the climate.
Given how important our climate is, I’m sure Tim Flannery, The Climate Council, The Australian Conversation Foundation, and The Australian Greens will join us in demanding that the BOM and CSIRO datasets are independently audited. Naturally, all of us would want to ensure our climate data is of the highest quality possible and not subject to any kinds of confirmation bias, or inexplicable adjustments. Right? And maybe its even worse than we thought, so they will want to check, yes?
Let’s leave no stone unturned in making sure we understand the threats to the Australian environment, the impact on our farms and homes, and on our National Balance Sheet! How could any Green disagree?
Dennis Jensen talks about the response he got from the BOM and the questions he did not get answered:
” … the BOM state the temperature trend prior to 1910 is unreliable. But the IPCC use data on Australia going back to 1850. So [...]
Heatwaves have become a publicity tool. Far from there being a clear trend in Australian heatwaves, Geoff Sherrington shows that it’s also legitimate to claim heatwaves were worse 80 – 100 years ago in Adelaide and Melbourne and things are getting better. Those officials who cherrypick their claims might be technically correct, but it’s outrageously deceitful and unscientific at the same time.
Just how hard is it to get a record heatwave? It’s so easy that if it’s summer in Australia, it’s hard not to set a record. That’s because heatwaves come in so many flavors – there are seven capital cities which can all have 3 day, 4 day, 5 day or 6 day heatwaves. Then there are the heatwaves over 40C, or over 38 C, or over 35C… already that makes 84 flavours of wave. If a hot spell doesn’t break one type of wave, it could easily break another. Then there is the pre-heatwave, and there would be another 84 types of heatwaves that we haven’t had, but might get, you never know. You might think I’m kidding, but pre-heatwaves get headlines already:
“More Canberra heatwaves forecast”
“A heatwave could return to Canberra next month, [...]
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