We have all seen the media beat ups about the “Great Four day Perth heatwave 7th to 10th Feb 2016” – never a mention that that the ever expanding Perth urban heat island UHI might contribute to this event. Credit where credit is due though, the original BoM forecast was pretty good. Unlike their Brisbane and Queensland efforts this year.
Check out the statistics assembled by Chris Gillham in Perth – his website has much information on WA and Perth climate matters. Interesting that Perth Airport temperature data shows the “Great Four day Perth heatwave 7th to 10th Feb 2016” was exceeded by several past events at that site.
The Sydney Morning Herald reveals – Sydney area an ‘urban heat island’ vulnerable to extreme temperatures 14 Jan 2016 – It is welcome that such basic facts can be spoken about.
Research by the BoM 15 years ago found measurable urban effects in small Victorian centres Hamilton, Camperdown-Cobden, Colac. The BoM paper can be downloaded as a 216KB pdf-
Just noticed this HT Graeme No.3 – But today I see Adelaide (Kent Town) recorded 7.9°C which just beats the previous record of 8° in 1987 – data starts 1977.
Parafield Airport had 5.7 this morning – Only 0.1 above the December record minimum of 5.6 in 1995. All in the face of the increasing Adelaide urban heat island (UHI) influence.
Adelaide West Terrace 1887-1979 recorded 6.8 in 1955.
Ponder these quotes from the BoM to the ABC –
[Bureau of Meteorology forecaster Sean Carson said temperature lows seen this week, along with last August’s extreme run of lows only occurred once a decade.
“August last year saw a pretty impressive run of overnight lows, where we saw eight consecutives nights below -5C, with the lowest night in that sequence getting all the way down to -8C,” he said.
“But prior to that it is probably something we only see every 10 to 15 years where we get such cold minimums.”
Mr Carson said this “impressive” run of temperatures was more common in the 1970s.
“It used to be fairly regular before the 1970s, before we saw a lot of development across Canberra, which did give Canberra a little bit of heat coming from industry,” he said.]
So is the non-urban classification for the Canberra Airport BoM station up for review?
From page 76 of “Techniques involved in developing the Australian Climate Observations Reference Network – Surface Air Temperature (ACORN-SAT) dataset” CAWCR Technical Report No. 049 – BoM March 2012
The BoM Cobar Meteorological Office is adjoining housing on the north edge of Cobar, a mining and pastoral town in remote New South Wales population ~4,000. A BoM MO is professionally staffed.
The Airport is several km away to the SW – these minimum temperature readings for May show a UHI of a few degrees most mornings.
Obviously if mornings are too breezy – the relationship gets perturbed. You can see here that lately there are only light zephyrs in the early mornings when minimum temperatures are recorded.
The BoM classifies Cobar MO as “non-urban” – despite housing a stones throw away. Not on this planet.
Adelaide Now is carrying this news item (HT Chris Gillham) – Weather station near Adelaide High School to more accurately measure climate change will involve cutting 18 Parkland trees
The article says – [The bureau wants to relocate to the Parklands site to be able to make comparisons with historical readings gathered at a previous station which operated near the site between the early days of the South Australian colony and 1979, when the city station was moved to Kent Town.
The data from the new weather station would be able to be accurately compared to historical figures to determine the impact of climate change.]
So the BoM thinks that relocation on this or that postage stamp area of parkland enclosed by the huge and ever increasing urban heat island of the ever expanding and infilling Adelaide suburbs – will somehow mean that “…data from the new weather station would be able to be accurately compared to historical figures to determine the impact of climate change.”
And of course this is the same BoM who thinks Canberra Airport is “non-urban”
Of course you are seeing this in MSM headlines?
Yesterday Sydney barely struggled above 20°C on Australia Day the 26th January 2015 – in the face of the ever growing urban heat island too – 30 minute data preserved – online here – In 1965 the max was 20.7 (ACORN says 20.9) then in 1957 the max was 19.4 (ACORN said 19.6) Daily max and min data – as I write the BoM is slow to update the max for Monday. But Australian Weather News already has Monday the 26th at 20.0
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 –
I was away all yesterday in the boondocks and heard on the car radio news of the Brisbane storms with hail and damage. Brisbane smashed by storm super cell: Premier calls in Army to help with clean-up –
I just post this map of rain up to 9am on the 28th (recorded up to 4am) to float the idea again that the urban heat island can attract rain. The mechanism could be due to the man made increased albedo contrasts accentuating the formation of convective storm cells. I am interested to see what readers think. I realize there is a greater concentration of rain gauges in SE Queensland.
I have had previous posts on this subject but not on Brisbane. In February I posted – Did the Adelaide urban heat island (UHI) increase rain there last night? and there is a link there to an example from Melbourne. I am sure I have read of examples from books and published papers.