Australians cool Melbourne

Posted: January 23, 2015 by tchannon in Surfacestation, UHI, weather

Image

Mr Trewin also noted that the Bureau had recently changed its Melbourne monitoring site from the Royal Society of Victoria on La Trobe Street in the city to Olympic Park, near Rod Laver Arena. Maximum temperatures recorded at the new site were on average 1.2 degrees cooler, particularly on cool days, because air coming from the south and west was travelling over parklands rather than the through the city.

http://www.theage.com.au/victoria/melbourne-weather-summer-2015-still-hot-just-last-year-was-hotter-20150119-12tbhi.html

h/t to handjive at notricks

Head image from an article by Anthony Watts at Steve McIntyre’s ClimateAudit 2007 article 6 years ago. (I’ve add the red circles)

Image

BOM report it here, no mention of why [wrong, see comment by jdmcl]. Above is how BOM show the station.

Even rainfall data will be wrong with those tall nearby structures and fences.

The Age reported the closure here. No mention of why.

Why the 6 year delay since so far as I know the new location already existed and bridging instruments is obviously impossible (must read exactly the same). How much longer had it been known?

Whilst seaching for links I came across a formal statement by a BOM official in relation to the 2009 fires.

Spot all the questionable statements but one relates to Melbourne

Many all-time site records were set in Victoria on 7 February, including Melbourne (154 years of record), where the temperature reached 46.4°C, far exceeding its previous all-time record of 45.6°C set on Black Friday (13 January) 1939. It was also a full 3.2°C above the previous February record which was set in 1983, an extraordinary margin for a site with such a long record.

Was it the La Trobe site?

There is a mountain of material on the La Trobe site if you search.

Post by Tim

Comments
  1. John Silver says:

    The location is the station and they relocated the location.
    Magic.

  2. This will be another excuse for them to adjust historic temperatures down then!

  3. ntesdorf says:

    The main BOM Station in Sydney needs investigation also as it is next to a 22 lane highway to the Bridge. The Melbourne location was a laughing stock from about 1950 until its recent move.

  4. jdmcl says:

    The BOM comment that’s mentioned in the article says

    “The effects of urbanisation have become increasingly visible in the 106 years of data at La Trobe Street. Wind readings progressively deteriorated over the years, due to obstruction by buildings constructed around the city, and were finally switched off in 2009.”

    … so contrary to what the article says, the BOM does provide a reason.

    The BOM comment also says

    “The official record of weather observations for Melbourne extends back to 1855, with a few breaks. It draws on observations from several locations, including Flagstaff Gardens (1858-1863), the Melbourne Observatory at the Botanic Gardens (1863-1908) and the Royal Society of Victoria on La Trobe Street (1908-2014)”

    … which means the old data will have been adjusted at three times, although the word “including” suggests even more times.

    It goes on to say

    “The two observation stations have now been operating in tandem for over 12 months. This is done so we can compare data and identify differences in the readings for forecast and long-term climate comparisons. Initial results suggest the new site shows similar rainfall and temperature readings in most weather conditions, although it is cooler in southerly winds and sea breezes.”

    This raises two issues
    (a) the comparison of the two sites has been done while the old site is suffering what’s probably its maximum urbanisation
    (c) adjustment should take into account windspeed and direction, but how do you do that when (i) wind recordings at the old site were known to be wrong because of the blocking effect of buildings and (iii) it would false to assume that winds from a particular direction would always have exactly the same impact on temperature.

    Personally I think the Melbourne situation is a good example of the obstacles to accurate tempeature adjustment.

  5. tchannon says:

    ” so contrary to what the article says, the BOM does provide a reason.”
    You are right, I’ll edit the article.

    [done, I missed it, a mistake]
    [next day… and thank you for pointing out a mistake]