Robot wrote on Jun 11
th, 2019 at 1:32am:
BOM explains why they make the adjustments here:
Yes.
"The standard scientific practice is to detect potential artificial jumps by comparing data from the station of interest (the candidate station)
with data from other nearby stations where the suspected artificial jump is absent (reference stations). If there is an artificial jump in the data, this will be reflected in the candidate station warming or cooling relative to other surrounding stations."
See 5.
"All maximum recordings before 1/1/37 at Darwin P.O. (014016) were lowered by 1.02C on this date due to changes in the local vegetation. These changes were made by the BOM based on maximum temperatures taken from the comparison station Wyndham Port (001005)."
https://wattsupwiththat.com/2019/04/08/darwin-temperatures-unscrambling-the-acor...Contributed by Bob Irvine.
Wyndham is 446Km. hardly what one could call "nearby".
How well do temperatures from Wyndham marry up with Darwin?
"In Fig. 2 it is obvious that the record has been compromised after 1936, probably by the vegetation issue identified by the BOM. A Pearson correlation of less than 0.5 disqualifies a comparison station based on monthly data according to the BOM methods. For the accuracy required by this post yearly data should be good enough and will almost certainly be confirmed if anybody wants to wade into the monthly data.
For the 10 years from 1927 to 1936 the correlation between Darwin PO and Wyndham Port is 0.39 which disqualifies Wyndham Port as a comparison station. Wyndham Port also has very poor or no correlation with Darwin Airport from 1942 to 1945 (correlation 0.03). The BOM should not have used Wyndham Port as a comparison station."
One would have to say not even close.