Please refer back to my first post for site specifications.
Station: Rutherglen 82039
Opened: 1913
Daily Temperature data from: November 1912
Data used to adjust Acorn sites at: —
Location: Co-ordinates -36.1048 146.5094
About 250km north-east of Melbourne
The screen is the white dot in the red ellipse.
Rutherglen is to all appearances a compliant site. However……
Rutherglen has been featured many times here, and at Jo Nova’s blog, and at Jennifer Marohasy’s blog, and in newspapers, and this has caused a lot of defensive postings by the BOM. Search and you’ll find the links. Rutherglen is part of the ACORN-SAT network, contributing to BOM analysis of Australian climate trends. One would therefore think the BOM would pay close attention to ensuring that Rutherglen is beyond further reproach.
As part of their response to another issue, the BOM released this Review of the Bureau of Meteorology’s Automatic Weather Stations which amongst other things has the inspection and maintenance schedule for weather stations.
The cream of Australian weather stations on which our climate record is based have just one inspection and one maintenance visit per year. Dr Bill Johnston asks, “Is the maintenance schedule up to the task of minimising bias in temperature readings, especially upper-range bias due to deteriorating albedo and other site conditions?”
What happens between these visits?
A colleague of mine visited Rutherglen last week and took these photographs.
From the dirt road:
While the grass is fairly short it has not been “kept trimmed to a few centimetres in height”.
The northern exterior of the screen:
Peeling, dull paint and mildew decrease the albedo, so the screen will be heated more by the sun.
The interior of the screen:
In between BOM inspections mud wasps have built a nest on the humidity sensor. This is an automatic weather station. Every minute this station transmits data to Melbourne Head Office including temperature at the last second of that minute and highest and lowest one-second temperatures within that minute, plus relative humidity and wind strength. Depending on the position and size of that wasp nest, data transmitted may or may not be reliable- or complete garbage.
Despite outward appearances (including in Google satellite imagery), this site is non-compliant, so temperatures recorded here are not reliable.
Another FAIL.
Tags: Acorn, adjustments, Australia, bom, temperature, weather
August 5, 2019 at 11:09 am
Ken this reads like something from Gilbert & Sullivan.
It’s almost funny.
But not quite as this is actually important.
This is the first time any of us have actually looked inside a BOM weather station. certainly I have not here at Mt Barker as that could be construed as ‘interference’ on private property.
But mud wasps are so so common in the rural areas of Australia. I’ve got them nesting outside my back door. They are harmless and never sting anyone.
But inside a BOM Stevenson screen ?. What impact does this have on the temperature sensors and humidity sensors etc.
By the way : If you need to get hold of me my contact details are
bhankin@adam.com.au
August 5, 2019 at 11:24 am
There are other implications for screens unattended for a length of time: bees, mice, frogs, snakes!
August 5, 2019 at 12:32 pm
Ken I was just looking at the BOM’s pdf about the Wyalla airport site in SA. I seriously doubt that it is compliant. There are plane taxying lanes 20 meters away. And as Wyalla is now sort of booming again. flight there are increasing. Here is the link :
I also looked at the Port Augusta BOM weather site.It seems compliant.
August 5, 2019 at 12:56 pm
This is supposedly one of the best of their sites, except that it doesn’t show warming, so they have to “homogenise” it with sites up to 260 km. away.
It is obvious that as far as doing their job the BoM couldn’t run a chook raffle in a pub.
August 5, 2019 at 5:06 pm
What do you mean Graeme when you write “It doesn’t show warming ” ?
August 8, 2019 at 4:11 pm
from the unaltered figures. After “homogenising” the figures it shows warming.
JoNova did a post on this site.
January 17, 2020 at 6:42 am
[…] a multi-lane highway, shaded by trees, or in screens that are covered in spider webs, invaded by mud wasps, or used by cattle as a back-scratcher. The area around the screens can be dusty bare dirt, […]