Southern Africa-Australia-Antarctica 14 Temperatures

This post refers to my analysis of recorded annual mean temperature trends at 14 stations extending from southern Africa to Austalia, New Zealand and Antarctica.  The stations were all with long records (many over 100 years) and located in rural areas or small towns.  The analysis used raw data (as recorded, without any adjustments) as published by KNMI (the Dutch Meteorological Institute or BOM (the Australian Bureau of Meteorology). Polynomial curves of best fit were added to the plots.

map-australia-2

In all, a total of 257 stations worldwide were used in a larger analysis, but these have been summarised here by selecting 14 stations in the Southern Africa-Australia-New Zealand region. The selected stations were not “cherry-picked”. Links to separate summaries in three other regions, with a total of 36 stations, are given below.  Links to the analyses at the 257 individual stations (worldwide) are also given below.

No attempt was been made to derive “regional average” temperature trends. Instead analyses were made at individual stations as this was considered to be more physically meaningful and practical using thermometer observation data. Using this approach any inconsistencies due to data quality would be identified as outliers.

The analyses at these 14 stations showed that:

  • Only about 20% of the stations had a well-defined cyclical long-term trend with periods (the time between peaks in the trends).  Commonly trend troughs occurred around 1940-1970 with trend peaks around 2010, although this does vary considerably.
  • About 90% of the stations showed a plateau or peak trend in the period since 2000.
  • At about 10% of the stations there no evidence of a peak in the trend since 2000.
  • About 40% of the stations had a neutral or negative overall trend over the past century.

Plots are shown below for the 14 stations.  It should be noted that the polynomial fit line (in red) can sometimes be misleading at either end of the series as the line is very dependent on the temperature values in individual years (this sensitivity does not occur away from the start and end of the series).

table-africaaustraliaantarctica-a

 

St Helena, UK  1892-2015

sthelena

 

Pietersburg, South Africa  1932-2015

pietersburg

 

St Brandon, Mauritius  1951-2015

stbrandon

 

Cape Leeuwin, Australia  1897-2016

cape-leeuwin

 

Marble Bar, Australia  1901-2016

marble-bar

 

Darwin, Australia  1882-2016

darwin

 

Richmond, Australia  1893-2016

richmond

 

Moruya Heads, Australia  1910-2016

moruya-heads

 

Lord Howe Island, Australia  1912-2016

lord-howe-2

 

Hokitika, New Zealand  1866-2015

hokitika

 

Macquarie Island, Australia  1948-2016

macquarie-2

 

Mawson, Australia  1954-2016

mawson-2

 

Halley, UK  1956-2015

halley-3

 

Amundsen-Scott, USA  1957-2015

amundsenscott

 

For convenience of management the 50 selected regional stations have been grouped into four large regions (see map below) as follows:

  • Americas region, 14 stations
  • Europe and northern Africa region, 9 stations
  • Asia region, 13 stations
  • Southern Africa, Australia, Antarctica region, 14 stations

world-map

 

Links to the analyses of the long-term temperature trends at the other 36 stations are presented within the other three large regional blog posts:

 

The analyses at the 50 worldwide stations are summarised in the blog post:

 

Similar links the the analyses of the long-term temperature trends at all 257 stations analysed are presented within 27 smaller regional blog posts:

 

Please let me know what you think of my analyses.    brigun@westnet.com.au

 

The Author:

This article was written by Brian Gunter of Narooma, NSW, Australia. In his previous life Brian was an engineering hydrologist involved over many years in the analysis of rainfall and river flow data for the planning of water resources projects in Australia, Asia and Africa. In recent years he has been one of the Marine Rescue NSW (previously Royal Volunteer Coastal Patrol) volunteer weather observers who operate the Narooma station for the Bureau of Meteorology.

 

 

 

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