Sigh. Changes to the irrigation schedule will swamp any natural temperature trend. And changes will have occured in recent years because the government has mandated irrigation restrictions that even apply to bore (well) water, which is likely used at Geraldton.

Carnarvon airport doesn’t look irrigated, although there is extensive agricultural irrigation nearby.

I know that Halls Creek airport isn’t irrigated, nor is Meekathara airport and neither have nearby agriculture.

I’ll try and put together a comparison of these 4 airports to get a feel for the effect of irrigation.

http://images.google.com.au/imgres?imgurl=http://www.geraldtonairport.com.au/Images/photoAirport.jpg&imgrefurl=http://www.geraldtonairport.com.au/technical.html&h=543&w=740&sz=114&hl=en&start=2&um=1&tbnid=r_RR0h2WfQ6fvM:&tbnh=103&tbnw=141&prev=/images%3Fq%3Dgeraldton%2Bairport%2Bpictures%26um%3D1%26hl%3Den%26rls%3DGGLL,GGLL:2008-22,GGLL:en%26sa%3DX

The water will create a micro-climate that rapidly decreases with distance.

Over time 2 things have happened. One is that as CBDs get built up weather stations get moved to less urbanized locations further away from the water. This happened in Perth in 1992 and the move took the station about one K further from the water.

The second is that the water gets moved further away due to land reclamation. I’d have to check old maps to be certain, but at some point Perth’s river shoreline has been moved at least 300 meters away from the CBD.

scott, most of the airports are not airports in the sense a North American would recognize. I am familiar with a number of them. Most are 90% grass or bare earth with a single concrete strip and a couple of modest buildings.

One of the airports in the network, Halls Creek, doesn’t have any buildings, at least it didn’t when I was last there 10 years ago.

I very much doubt there has been UHI creep at any of the airports I know. I’d say they will be some of the best stations in Australia. Except, I think some of them are irrigated. I recall Geraldton Airport had nice green grass in the middle of summer.

I’vé made a couple of comments on the Australian RCS in the past. A lot are at airports, though most not at all major. Some of the stations appear to be excellent, others might not quite make Anthony’s 1 rating! Have a browse through the BOM site photos at http://www.bom.gov.au/climate/change/reference.shtml

For instance Canberra’s RCS is at the airport (Google Earth Lat long):
35deg 18min 17.45sec S 149deg 12min 04.78 sec E
You can see the new car park under construction next to it (now finished) on Google Earth, and it is down (prevailing) wind from the RAAF Tarmac. FWIW, Canberra just had its second hottest June on record…

Just how does GISS choose their sites, anyway? (Not the first time THAT question has been asked.)

It’s all in the money.

This is the problem with ALL the station data. I bet if you had detailed history on every site, all of them would have some major instrument/siting change that would significantly contaminate the data. And any attempt to “adjust” the data to remove that contamination is just a guess. The effect of siting, the adjacent tollroad, general UHI, the sidewalk, the parking lot, etc etc, are not a one-step or linear process.

It’s as if no one understands what is meant by 1918 levels of CO2 production. Energy use has contributed to man’s life extension, that fact cannot be denied. Aren’t humans to be treated as part of the ‘natural environment’? Humans aren’t aliens afterall.

I would have thought that there would be an adult somewhere on the staff that would have said “And the point is? All of the plants will be in an elevated CO2 environment and will grow better, so the nutsedge won’t be any more invasive than it already is” but, sadly, I was expecting too much.

If the modern site is sheltered from the West, that would explain the sharp increase in winter temperatures at the time of the move, as cold westerlies are the prevailing wind in Sydney in winter.

The UHI impact on this site must be enormous, as it has transformed from a parkland location to being a few meters from the busiest piece of road in Australia. There was no adjacent roadway until the Bridge was constructed in the 1930s.

I believe Phil Jones (HADcru) dumped Sydney observatory in favour of Sydney Airport many years ago (the airport having its own UHI issues).

There is one splendid site in sydney – Fort Denison, which is an island in the harbour. Unfortunately, it no longer collects temp data (if, indeed, it ever did).

No matter how crazy those means may appear to outsiders.

You can see that GISS also stopped collecting data from Sydney in 1992, but it still collects data from Sydney airport, which has a huge UHI.

(I’m not sure how high quality the BoM network really is. Many are towns of various size or small regional airports.)