We have all seen and heard the media blitz on the subject – 2013 was hottest year on record in Australia, Bureau of Meteorology says –
Most of us have little idea of the extent to which the BoM ACORN SAT temperature series has older data adjusted cooler to increase the warming trend.
This chart shows the monthly mean temperature ACORN SAT data that the BoM rely upon for their statements and shows the strongly cyclic nature of the 12 month average.
RSS satellites measure brightness temperature anomalies in the lower troposphere (TLT) – that thin skin of air centred on about 2 to 3km high. It is interesting that the rankings of the anomalies for the hottest months over Australia from the BoM go, Sep 2013 2.75 – Apr 2005 2.66 – Aug 2009 2.47.
However when you make global temperature anomaly maps for the RSS satellites lower troposhere series and eyeball the maps – the ranking looks to be – Aug 2009 hottest – Apr 2005 2nd hottest and Sep 2013 3rd hottest.
Aug 2009
Apr 2005
Sep 2013
RSS do not publish an Australian anomaly time series.
I put these maps up to show that all might not be as cut and dried as the BoM would have you believe.
Can I focus on 2 other records.
Australia’s warmest month on record – January 2013.
Australia’s hottest summer day on record (7 January 2013).
As John McLean points out – “The statement from the Bureau of Meteorology didn’t do anything about describing the reasons for the higher temperatures”.
If you go back to January and read the BOM Media Releases at the time you get conflicting views on the cause of the high temperatures.
The BOM Meteorologists said:
“The late onset of the monsoon, that would bring some relief in the way of cloud cover and rain, has not yet eventuated. As a result extremely hot air masses are developing in the north of the continent and being driven into southern Australia ahead of each cold front.”
The BOM Climate Scientists attributed the hot weather to “climate change”!!!
www.bom.gov.au/announcements/media_releases/ho/20130109.shtml
The BoM says January 2013 was our warmest ever January anomaly –
www.bom.gov.au/climate/current/annual/aus/
Sep 2013 was our warmest monthly anomaly.
I agree the BoM should explain the meteorological reasons for the heat more.
As an example the Monthly Climate Summary for Sep 2013 –
www.bom.gov.au/climate/current/month/aus/archive/201309.summary.shtml
only talks of temperature and rain.
A Martian dropping by for a read would assume that was all the BoM knew.
It is not good enough.
There were fairly large negative rainfall and water vapour anomalies across much of Eastern Australia in 2013. Which indicates the reason for the hot year was less clouds, and which explains the LTT and ST discrepancy. Not the warming profile predicted by GHG warming and the decreased WV is the opposite of what is predicted.
The large positive WV anomaly around Alice Springs looks a bit suspicious as there is no corresponding positive rainfall anomaly. Could be newly installed irrigation.
www.bom.gov.au/jsp/awap/rain/index.jsp?colour=colour&time=latest&step=0&map=anomaly&period=12month&area=nat
www.bom.gov.au/jsp/awap/vprp/index.jsp?colour=colour&time=latest&step=0&map=vprph15anom&period=12month&area=nat
The surface and troposphere temperature divergence is a real phenomena, but the causes are the opposite of what GHG warming predicts, and hence it’s a taboo subject in the climate science mainstream.
Warwick:
this might be of interest to you.
samuelgordonstewart.com/2014/01/bureau-overheat-figures-by-4-degrees-2013-was-not-australias-hottest-year-on-record
He backs off a bit in his claim, but uses spreadsheets to back it.