I saw this referred to on media – Sydney has its coldest winter in decades – Checking the facts for Sydney Observatory Hill which averaged 7.2°C 1st to 15th July 2015 – I find the next coldest 1st to 15th July was 6.2 in 1971 a 44 year record which is amazing in the face of the ever increasing largest urban heat island (UHI) in Australia.
Keen eyed readers warned me of this news – Warmest June temperatures for Perth
Working down this station list for the Perth region – In a few days the June 2015 archive will be visible. I have the page saved offline if anybody wants it emailed. Badgingarra had 20.6 last month but in 1985 saw 20.9.
Garden Island had 19.9 equal with 2006. Gingin Aero has 20.9 but saw 22.9 in 1996 and 21 in 2000. Karnet had 17.8 but saw 18.1 in 2006. Rottnest Island at 19.7 was equal to 1997.
Looking around at other stations some closed – Guildford Post Office saw 21.3 in 1944. Upper Swan Research saw 21.6 in 1983. Rottnest Lighthouse read 20.2 in 1949.
I ask if you could take out a century of urban heat island UHI growth – would the BoM claim stand up? I think on balance no doubt last month was very warm in Perth but the claim of “warmest ever” is not the most robust of claims to trumpet from the centre of a huge urban area.
Really strange misinformation – the facts are very simple – Canberra is having a record run of cold nights for this early in June. Yet today the ABC reports – Canberra’s extreme run of overnight lows ‘only seen every 10 to 15 years’ – What is the BoM smoking. Yesterday the Canberra Times quotes the BoM to write – Canberra weather: Cold, frosty mornings to continue before a warm long weekend – Same style of obfuscation – avoid admitting a record at all costs. The Fairfax article confuses Monday and Tuesday – talks of warm weather to come. And there is this odd mention of last August that has nothing to do with anything. Weird mention of “every 10 to 15 years” – no it is the coldest run of nights this early in June for 76 years!!! Then they throw in El Nino to appear all-wise. And our national policy is affected by the org generating this evasive twaddle.
Here is a Table of sorted June minimums for Canberra down past minus 5.1. The record to break is – Tuesday the 2nd -7.0, Wednesday the 3rd -5.1, Thursday the 4th -6.9, all time record run of cold minimums this early in June. Case closed.
The Courier Mail reported 22nd April – Several Queensland towns hit record low April temperatures.
Hughenden Airport broke the coldest night record including the Post Office – on the 22nd April – and then broke that again on the 27th.
Maryborough saw the same pattern with 6.2°C on 22nd and 5.5 on the 27th both breaking the previous record from 1966. Clermont Airport broke the Post Office record with 4.3 on the 27th – the Post office saw 4.6 in April 1999.
On April 30th Kulgera in southern NT had a record April low of 1.5.
Alice Springs on 1st May hit 1.6 making it the coldest 1st of May since 1881 or whenever the Post Office commenced.
On the 14th Eyre in WA hit -2.5 a record low.
The Courier Mail reports on the 14th – Brisbane wakes up to chilly morning as southerly change pushes dry air and cold winds –
On the 15th Tamworth AP read -4.5 a record low.
On the 16th Broome AP read 7.7 an equal record low.
On the 16th West Roebuck (near Broome) read 5 smashing the previous record of 7.
On the 16th Marble Bar read 7.5 smashing the previous record of 9.4.
On the 25th Newman AP daily max 14.7 smashing the previous record of 16.
Imagine the BoM media releases if the above were all warm April & May records.
If anybody knows of other records – comment or email them – thanks.
A reader has sent in these maps observing some features live on from year to year. “Compared to 2014, west of Strasbourg is more or less the same in 2013, and there is another one near Manosque, northeast of Marseilles, repeatedly. The Paris heat island is in all of them, and the last 3 years Chalons en Champagne is always too cold and inland from Brest too warm.” I agree the French data looks poorly calibrated – will try and get a new 2010 map with the same normals period as the others.
2008 – 2009 – 2010 – 2011 – 2012 – 2013 – 2014 –
This is the second episode in the Cobar ACORN-SAT series examining BoM adjustments to the CDO temperature data – here I start to look at adjustments to minimum temperatures. The 1st episode looked at maximum temperatures. A list of ACORN adjustments to Cobar data is here and you can see the first min adjustment listed is 1st Jan 1972 meaning the adjustment factor applies to all data earlier than that. You will see it is labelled as “Statistical” meaning there is no evidence for it in station diaries or admin records but it derives from computer driven comparisons sifting data differences from multiple stations as far away as Parkes and Hillston – see map. In this case of the 4th adjustment the following stations data was used.
Making the chart of Cobar annual minimum temperatures compared to ACORN-SAT my eye was caught by the adjustment starting in 2006 and affecting all earlier years which I have marked with a blue 6. That is unlisted in the ACORN-SAT documentation and is substantial at about -0.4 degrees C. The slight mismatch between Cobar Met Office and ACORN from 2007-2013 is due to rounding differences because I have made my ACORN annuals by averaging a year of daily data which I leave as produced by Excel with multiple decimal places.
The next adjustment to look for is at 1971 where I have the blue 4, which is the 4th adjustment in the ACORN list and is listed at -0.49 degrees C. The increased departure of ACORN cooler than Met Office to about -0.9 is obvious on the chart.
Examining this adjustment in greater detail I have made a chart comparing Cobar MO and ACORN version with nearest neighbours Bourke, Wilcannia and Nyngan. The average difference between the 1971 & 1972 readings for these 3 stations is +0.2 at Cobar MO, +0.4 at Bourke PO, +0.4 at Nyngan, and -0.4 at Wilcannia, an average for the 3 Cobar neighbours of +0.13, not very different from the +0.2 that we know happened at Cobar Met Office. But instead of leaving the higher quality Cobar Met Office readings well alone – what does the BoM decide to do with their adjustment #4? They take off 0.49° making the 1971-1972 difference now 0.7 – greater by 0.3 than any of the neighbours. Presumably the BoM justify this by their computer driven comparisons with sites as distant as Parkes.
If the reasons for an adjustment can not be seen in nearest neighbours then it must be an exercise in fantasy to search for a reason in a cherry picked array of more distant stations which are all of poorer quality than Cobar Met Office.
It is interesting to check the differences in annual minimums between Cobar Met Office and Cobar Airport which are only about 7 or 8 km apart. You might expect them to be very similar and in lockstep – not so from the chart.
Note the BoM never refer to Cobar Airport data in ACORN-SAT – but we are free to check it out.
First there is no evidence here of a step or jump around 2006 – 2007.
While there are such wildly varying and apparently random differences between these two very adjacent sites – what on earth can the BoM learn by comparing Cobar with Parkes – or indeed any other station in their adjustments list.
These are the sort of unsafe foundations that pro-IPCC climate science is based on.
A reader has asked me to look at how ACORN-SAT has adjusted Cobar temperature data. Cobar is an old site with Post Office data from 1881 – then in 1963 the BoM opened the Cobar Met Office on the north side of town. Map from Google Earth with MO marked by “green X”. Detail of Met Office – note housing adjacent. A Met Office is of course purpose built and staffed by BoM professionals. Then in 1994 an Airport station commenced with an AWS.
ACORN-SAT starts with a positive adjustment to the max of 0.41 prior to 1 Jan 1995. Table of ACORN-SAT adjustments for Cobar. I will start by examining the evidence for that first adjustment 1 Jan 1995. This chart shows Cobar district annual max t data from 1963 – the 3 Cobar station plus Bourke PO and Airport – then Wilcannia and Nyngan. All data from the BoM CDO www site. I have marked the year 1995 with a “green 1” – and the first adjustment to Cobar Met Office is indicated by the “green 2”.
Here is a map of NSW showing all stations used in the various ACORN-SAT adjustments of Cobar. Here is a list of stations used in the first adjustment (1 Jan 1995) – the only one we will discuss at this time.
An important note – BoM ACORN-SAT does NOT use Cobar Airport data, despite the two stations only being about 7km apart and as the chart shows the Airport and MO annual max data are in near lockstep as you would expect.
I am saying this first adjustment is invalid for the following reasons.
 The Airport data for 1994 & 1995 closely agrees with Met Office so this fact must override whatever signals the BoM computes from “data mining” at diverse stations up to a few hundred kms away some in very different climate zones.
 The Cobar Met Office is a purpose built facility staffed by professionals so that data must be considered a more reliable baseline compared to amateur run sites not owned by the BoM.
 If there was a valid reason to adjust Cobar MO data prior to 1 Jan 1995 it is ludicrous to think there would not be a reason revealed in the Met Office admin records.
That is my case that the ACORN-SAT version of Cobar fails at the first hurdle.
There has been much valid criticism of ACORN-SAT in recent months and the entire project must be scrapped.
The BoM was asked to calculate the climate of the Canberra district in the process of deciding on a location for the Australian Federal Capital Territory – Chris Gillham alerted me to this report and he has his own comments on the data in a 1Mb pdf report.
Looking at the temperature data in the Table on page 7 & 8 of the pdf report I decided to check on Goulburn, Cooma and Yass getting data from BoM CDO.
In the case of Goulburn the annual mean temperature was 56.1°F for the 46 years prior to 1910 – this equates to 13.4°C and the station was at an altitude of 702m. Now Goulburn Airport is at an altitude of 640m so the 13.4 in town would equate to 14 at the Airport assuming a standard lapse rate. The Airport in the ten years 2004-2013 averaged 13.1 – so even if we take of 0.2 from the Goulburn Town temperature for possible non-Stevenson screen exposure – we still have Goulburn 105 years ago 0.7 degrees warmer than the last ten years.
In the case of Cooma the annual mean temperature was 54°F for the 44 years prior to 1910 – this equates to 12.2°C and the station at Lambie Street was at an altitude of 812m. Now Cooma Airport is at an altitude of 930m so the 12.2 in town would equate to 11.04 at the Airport. The Airport in the ten years 2004-2013 averaged 11.15 – If we take of 0.2 from the historic Cooma temperature for possible non-Stevenson screen exposure – Cooma 105 years ago might have averaged 10.85 or 0.3 degrees cooler than the last ten years.
Yass is complicated by stations closing in the last ten years with only one month overlap. I have done the calculations and allowing for the site change and altitude differences there is near zero difference between the Yass district pre 1910 and in the last ten years.
Upshot is there seems to be no global warming or significant climate change around Canberra since the 19th Century.