Australian Climate Reference Stations

Its seems that Australia’s Bureau of Meteorology network of reference climate stations (RCS) has come under question with respect to the level of compliance with the American NOAA/NCDC 5 classes of station quality ratings. NOAA’s new Climate Reference Network specifications esp. section 2.2.1 define the levels with 1=best, thru 5=worst.

Class 1 (CRN1)- Flat and horizontal ground surrounded by a clear surface with a slope below 1/3 (<19deg). Grass/low vegetation ground cover <10 centimetres high. Sensors located at least 100 meters from artificial heating or reflecting surfaces, such as buildings, concrete surfaces, and parking lots. Far from large bodies of water, except if it is representative of the area, and then located at least 100 meters away. No shading when the sun elevation >3 degrees.

Class 2 (CRN2) – Same as Class 1 with the following differences. Surrounding Vegetation <25 centimetres. No artificial heating sources within 30m. No shading for a sun elevation >5deg.

Class 3 (CRN3) (error >=1C) – Same as Class 2, except no artificial heating sources within 10 meters.

Class 4 (CRN4) (error >= 2C) – Artificial heating sources <10 meters.

Class 5 (CRN5) (error >= 5C) – Temperature sensor located next to/above an artificial heating source, such a building, roof top, parking lot, or concrete surface.

The Bureau provides a BOM Station site specification on its web site; a document of some 90 pages written in 1997. Some of it is interesting reading:

A Reference Climate Station(RCS) is a meteorological station with a climatic record suitable for monitoring long term trends in the climate of a region. The WMO   (WCDP 1986) has identified the minimum RCS network requirement as 2 – 10 stations per 250,000 km2, preferably with an existing climate record of at least 30 years. The Bureau is initially aiming to ensure that at least 1 station per 250,000 km2 is designated as an RCS. The RCS should give an adequate representation of all the climatic zones of Australia. Island stations and stations in the Antarctic could also be designated as RCS.

For a standard Bureau staffed observing station, the instrument enclosure is a 17 metres by 17 metres square enclosure in the middle of a 30 metre by 30 metre square buffer zone aligned in the true North – South direction.

The enclosure area is to be level, clearly defined and covered with as much of the natural vegetation of the area that can be kept cut to a height of a few centimetres. The enclosure area should not be artificially watered. Concrete or asphalt walkways should be kept to the minimum number, only being installed where the surface is likely to be rendered impassable or unsafe in wet conditions, and in any case be no wider than 0.5 metres.

The buffer area around the enclosure must also be covered by the natural  vegetation or ground cover of the region which can be maintained below approximately 0.5 metres in height.

As a general guide, the distance of any obstruction less than 15 metres in height and of an isolated nature from any point in the enclosure is to be at least 4 times the height of each obstruction away from the enclosure.

For obstructions of a greater height than 15 metres or of a more general nature, the distance to the enclosure will need to be increased (up to 10 times the height of the obstructions if they cover more than 45O of azimuth).

Only shelters approved by the Bureau shall be used as the design of the shelter has a marked influence on the readings of the thermometers inside the shelter.

If a shelter is required at locations where no instrument enclosure is to be provided, it must be installed in an area that is level and covered with either the natural vegetation of the area or unwatered grass, which needs to be kept trimmed to a few centimetres in height. The site should not be in a hollow or on a steep slope. The shelter should be freely exposed to the sun and wind, and not shielded by or close to trees, buildings, fences, walls or other obstructions. It should also not be close to extensive areas of concrete, asphalt, rock or other surfaces which may locally alter the air temperature at the site. In areas where these surfaces are unavoidable, a minimum clearance of 5 times the width of the unrepresentative surface is recommended.

Sites such as Surfacestations.org, wattsupwiththat and Australian Climate Network provide some interesting research and analysis for both the US and Australia.

I drive past one of these stations each and every day (photo to come) and have been considering doing a little bit of my own research. So today (24/03/2010) thought I’d add my little bit to the discussion. So far I have only looked at the Australian RCS in detail, but there are multiple other ‘high-quality climate sites‘ listed at the BoM site.

Site: Dalwallinu – 008039 – How much effort would it take to have located this site better? At least an effort could have been made to locate it away from roadway, and a little attention to clearing the area would be beneficial. This site is clearly not a CRN1.

Fails BoM’s own specifications.

Site: Lake Grace – 010592 – Well the railway tracks wouldn’t help much here. Wonder if there is actually any rail traffic still travelling the line.  The green shed is definitely with 100m and probably within 30m. The trees would definitely provide >5deg shading. This one would probably rate CRN3 and have its own >=1C anomaly.

Fails BoM’s own specifications.

Site: Maree Research Station – 017031 – There is so much wrong with this that it really takes the picture to describe it. Can one assume that the red 44gallon drum (to the right of centre) is most likely an incinerator – I would hope not!! This site doesn’t even make it to CRN5 as far as I am concerned – that a >=5c anomaly.

Fails BoM’s own specifications.

Site: Tibooburra PO – 046037 – On a road and a driveway! Surrounded by metal buildings and fence all within 30m. Probably a CRN3 or a >= 1c anomaly.

Fails BoM’s own specifications.

Site: Moruya Head Pilot Station – 069018 – Obviously a very pretty place, but the station is within 10m of buildings. Another CRN4 or a >=2c anomaly.

Fails BoM’s own specifications.

Site: Wilsons Promontory – 085096 – Another beautiful place with great sea views. Pity the station is sitting on rock and within 10m of buildings and concrete pathways and rock walls (how much heat do they retain??). Another CRN4 or >= 2c anomaly.

Fails BoM’s own specifications.

 

Site: Cape Otway Lighthouse – 090015 – A little hard to tell how far away the building is in the BoM photo. There is another one that gives a clearer picture tho, see here. Now as far as I am concerned that is an old brick building with a nice white paint job and not a lot over 10m from the station. The area is hardly flat and surrounding vegetation is hardly less than 25cm. Another CRN3 with a >=1c anomaly.

Fails BoM’s own specifications.

Site: Cape Nelson Lighthouse – 090184 – Those metal buildings on the right are easily within 20m and the surrounding vegetation is obviously above 25cm. Yet another CRN3 and a >=1c anomaly.

Fails BoM’s own specifications.

Site: Eddystone Point – 092045 – Once again a nearby building, albeit small, with surrounding vegetation above 25cm. Another CRN3 and a >=1c anomaly.

Fails BoM’s own specifications.

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One Comment Add yours

  1. rogerthesurf says:

    Yup ground base data is open to all sorts of anomalies.

    Check out this video of questions in the house about the NZ climate readings.

    http://www.youtube.com/user/inthehousenz#p/u/2/Roku_QeiE3s

    We have got the data adjustment disease as well,

    Cheers

    Roger

    http://www.rogerfromnewzealand.wordpress.com

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