As the sun brightened the balance was dynamic.

Jovial Monk wrote on Aug 8^th, 2017 at 11:23am:



Still on about that acutely human need for balance?

Historic climate data is being destroyed

The Bureau have a budget of a million dollars a day, but seemingly can’t afford an extra memory stick to save historic scientific data.

In the mid 1990s thermometers changed right across Australia — new electronic sensors were installed nearly everywhere. Known as automatic weather sensors (AWS) these are quite different to the old “liquid in glass” type. The electronic ones can pick up very short bursts of heat –  so they can measure extremes of temperatures that the old mercury or liquid thermometers would not pick up, unless the spike of heat lasted for a few minutes. It is difficult (impossible) to believe that across the whole temperature range that these two different instruments would always behave in the exact same way. There could easily be an artificial warming trend generated by this change (see the step change in the graphs). The only way to compare the old and new types of thermometer is to run side by side comparisons in the field and at many sites. Which is exactly what the bureau were doing, but the data has never been put in an archive, or has been destroyed. It’s not easily available (or possibly “at all”). We have this in writing after an FOI application by Dr Bill Johnston (see below).

The BOM stated that “in accordance with records management practices”, the field books for early 2013 at Canberra Airport were  “disposed of” twelve months after the observations were taken. By mid 2014 the situation was even worse (if that were possible). The more recent Canberra Airport records didn’t even have field books to be destroyed. There were no records to be disposed of.

He commented this week on the scant evidence that was available and the potential for a undocumented warming effect:

Comparisons between screens were done at one site using PRT (Platinum Resistance Thermometer) only and reported as a “preliminary report”, which is available; but after Automatic Weather Stations (AWS) became primary instruments, as I’ve reported before, the Bureau had an internal policy that parallel liquid-in-glass thermometer data were not databased. Furthermore, they had another policy that paper-data was destroyed after 2-years. So there is nothing that easy available….   

The only way to compare AWS  and Liquid in Glass, is to hunt for sites where there is overlap between two stations; where the AWS is given a new number. This is possible BUT the problem is that the change-over is invariably confounded with either a site move or the change to a small screen.

So, we suspect that the introduction and reliance on AWS has led to artificially higher maxima (and thus record temperatures) than in the past, but we have no way of knowing for sure and how much.

How can the CSIRO hope to produce reliable climate modelling with any number of climate scientists when the BOM cannot produce reliable temperature data?  Garbage in, garbage out.

JoNova is not a scientist. She is a denier and promotes denialism with lots of lies.

Sorry, not worth considering. Come back when you have some real evidence.