ELECTRONIC probes in automatic weather stations officially replaced mercury and alcohol thermometers as the primary measure of surface air temperatures across Australia on 1 November 1996. While this was the official change-over date, the transition had actually begun in the early 1980s for some weather stations and is continuing – with temperatures still recorded manually at just under 200 weather stations.

The number of automated weather stations measuring temperatures with electronic probes (AWS in red) versus old-style weather stations still using mercury thermometers that are read manually (blue line).

Given these are very different methods of measuring temperatures, it would be assumed that there are dozens of reports published by the Bureau of Meteorology (BoM) that document how comparable the measurements have proven at different locations, and under different conditions. Yet there are none!

Furthermore, the BoM have a non-standard method for measuring temperatures from the new devices as I detailed in a blog post last October entitled ‘Averaging by Convention – or Not’.

While the Bureau maintains that temperatures from AWS and traditional mercury thermometers are equivalent, preliminary analysis of temperature data from electronic probes and a mercury thermometer located in the same shelter at the same official weather station at Mildura indicates that there is a statistically different – with the first probe (in place from 1996 to 2000) recording too cool, and subsequent probes too warm relative to the mercury thermometer. More information on this analysis can be found at ‘BoM blast for dubious record hot day’.

Jennifer Marohasy
Sunday 11 February 2018

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My latest scientific publications, including on rainfall forecasting, are listed at the Climate Modelling Laboratory website.

I wrote the following two statements down on a scrap of paper when I was an undergraduate at the University of Queensland in the early 1980s.  They seemed to resonate more with me as each year passes:

1. Belief in the truth of a theory is inversely proportional to the precision of the science.

2. The creativity of a scientist is directly proportional to how much [s]he knows, and inversely proportional to how much [s]he believes.

For many years this website operated as a weblog, rapidly building a regular readership of several thousand.   Since 2007 the entire website has been archived by the National Library of Australia, annually, each February.

I moved to Noosa, in southeastern Queensland, a few years ago. In 2015, I established the Climate Modelling Laboratory to progress my work with John Abbot developing a technique for monthly rainfall forecasting using artificial neural networks: a form of artificial intelligence/machine learning/big data analytics – finding patterns, building models, projecting foreward, measuring the model’s skill at forecasting.

As well as interrogating large datasets, I enjoy swimming in the ocean, yoga, meditation and the occasional walk in the rain. My heros include William of Ockham, Thomas Huxley, Clement Wragge and Emile du Chatelet.

Jen cropped 70

For a list of my papers on rainfall forecasting and temperature reconstructions click here; a more comprehensive list of scientific publications is click here.  Over recent years I have been published in: Atmospheric Research, Advances in Atmospheric Research, Wetlands Ecology and Management, Human and Ecological Risk Assessment, Public Law Review and  Environmental Law and Management.

I was published every fortnight for about 10 years by The Land newspaper, Fairfax Media Ltd (April 2004 – November 2014).  I resigned as columnist, and also stopped regularly blogging, to concentrate more on my scientific research.

The skill of our forecasts can be measured in terms of root mean square errors (RMSE) and mean absolute error (MAE) relative to observed rainfall.  This means that our forecasts could be easily compared in a rigorous and quantitative way against the forecasts from general circulation models including the Bureau’s POAMA.  However, so far, the Bureau has resisted any comparisons being made, as I detailed in a letter to Simon Birmingham in August 2014, which can be downloaded here.  The skill of our rainfall forecasts is affected by the quality of the temperature series inputted as part of multidimensional arrays, which is why I have become somewhat vocal about the often ad hoc process of homogenization undertaken to temperature series by the Bureau.

I am also a senior fellow at the Institute of Public Affairs, with this work funded by the philanthropic B. Macfie Family Foundation.

For nearly two decades I have advocated the restoration of the Murray River’s estuary through removal of the 6.7 kilometres of barrage. From July 2011 through until August 2017 I maintained the ‘Myth and the Murray’ website.

On Line Opinion, Australia’s e-journal of social and political debate, published me from 2003 to 2017, with links to these articles here. I recently started writing for The Spectator, with my author page here.

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