Today I’m looking at sites that are apparently compliant but whose surroundings change over time. Like Rutherglen and Adelaide, Nuriootpa is an Acorn station.
Please refer back to my first post for site specifications.
Station: Nuriootpa 23373
Opened: 1996
Daily Temperature data from: 1996
Data used to adjust Acorn sites at: Adelaide, Cape Borda, Snowtown
Location: Co-ordinates -34.4761 139.0056
About 75km north-east of Adelaide.
2018 BOM Site Plan:
2019 satellite image:
The station is on clear ground at a research station for grape growing, a few hundred metres from the town of Nuriootpa. The Acorn Station Catalogue says that the site is “… quite bare in summer. The vines are irrigated using drip-watering.” Note that the site plan indicates grape vines can be up to about 2 metres high in the maximum growing period. Note in the satellite image vines to the north seem to have more greenery than to the south.
Now consider site plans from 1996:
And 2006:
When this station first started (1996) there were no vines, just bare trellises, to the north. Vines were planted here in the early 2000s growing steadily.
Now I know a little about pumpkin vines and passion fruit vines, but very little about grape vines, but if vines are tall and thick at some times of the year and pruned back and leafless at other times, this will affect patterns of air flow over the site, and temperatures reached. Further, over 23 years the surrounds of the site to the north have changed from bare to overgrown.
This station may be spatially compliant but its surroundings have changed and regularly change with time. This is an Automatic Weather Station reporting continuously every minute for Latest Weather Observations. It is also an Acorn site- supposedly the best in the land.
Another FAIL.
Tags: Acorn, adjustments, Australia, bom, temperature, weather
August 6, 2019 at 9:53 am |
Interesting site Ken. I am not a wine grower. But I often see vines allowed to grow taller than two meters..More like ~ 2.5 meters.. And often they spill over and form a dense hedge in the process..
It all depends on the vine block management. Some vine block growers will prune vines back in Summer to allow wind & sun through to the the vines interior. This is to prevent fungal infections. But in a dry season ?
But also this site is in the midst of a totally vine growing landscape with few trees or shrubs…
Does this impact on the temperatures & rainfall measured ? I am not sure.
The vines are all drip irrigated through Summer. And the vines also respire moisture to stay cool & and as part of the photosynthesis process.
So there would be a huge amount of additional water vapour in the air during Summer as a result. ( Water mostly sourced from the Murray by the way but that is another issue entirely. )
( NB : BOM moved weather station at Rutherglen a few years ago from a vine yard block to a dry non irrigated site and that move saw higher summer maximums being measured. Ummm )
And I wonder has anyone has looked inside the Stevenson scree box recently ? For mud wasp nests etc. ?
And this is part of the ACORN set of sites !
August 8, 2019 at 3:58 pm |
The tendency is for grape vines to be grown higher these days. A fashion because several winemakers did so and won medals. Even if restricted to 2 metres they do form a hedge, although with some airflow low down.