Those familiar with the climate debate will naturally be aware that the rise in average official temperatures of 0.74C over the 20th century was an inherent component of IPCC’s conclusion of a future of dangerously high temperatures unless governments acted to reduce greenhouse gas emissions.

But how to interpret the fall of 0.7C in the average Australian temperature for 2010?

Continues…………

http://climaterealists.com/index.php?id=6997

NEW ZEALAND CLIMATE: TEMPERATURE AND PRECIPITATION VARIATIONS AND THEIR LINKS WITH ATMOSPHERIC CIRCULATION 1930–1994

M.J. SALINGER* and A.B. MULLAN, 1999

The climate patterns are described for three periods within the 1930–1994 record, with change-points around 1950 and 1975.

In the first period (1930–1950) New Zealand’s climate was cooler, and the prevailing west–southwest circulation was stronger (as noted by Salinger (1979)).

By contrast, national average temperatures increased by about 0.58°C in the second period, and there was more airflow from the east and northeast [1950-1976].

The last period (1976–1994) was one notable for frequent El Nin˜o events and comparative lack of La Nin˜a episodes. New Zealand-wide temperatures maintained their level of increase from the first period, in spite of more frequent airflow from the southwest.

http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291097-0088%28199908%2919:10%3C1049::AID-JOC417%3E3.0.CO;2-Z/pdf
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This is consistent with the EMD analysis and C).

Their missing period is 1910-1930 compared to the 7SS EMD analysis. They note a similar abrupt change up at 1950 in the Australian record. This statement is without citation:-

Longer term temperature records show this temperature increase amounts to 0.8°C since the beginning of the century.

Given the 1999 paper date, they are referring to the period 1900-1994 or 1999.

Salinger and Mullen used rotated principle component (RPC) analysis and a 10 year Gaussian filter to smooth the annual values to produce time series

2.4. Time series analysis
The RPC scores on each month were averaged over the January–December period to give annual scores. A 10-year Gaussian filter was used to smooth the annual values to produce time series to depict longer time scale trends and variability.

I’d like to know a lot more about the period 1900-1930 but from 1930 onwards there’s very little difference RPC vs EMD.

But smoothing both 1912 and 1930 makes it radically different.

I don’t know enough about the EMD algorithm yet to say why but I’ll send in an update with both 1912 and 1930 smoothed. There’s definitely a sensitivity involved that I don’t understand.

1912 is by itself but there are other cooler anomalies close to 1930.

It’s basically a crude sensitivity analysis, but it could be useful.

Ran the analysis again and the software duplicated 1911 for 1912 and 1929 for 1930.

The shape of the EMD trend changes radically.

The new starting data point at 1910 is 12.09 (11.93) and there’s a nadir at 1935 of 11.89 (11.96).

The EMD curve looks more like a multi-decadal cycle oscillating 0.3 C below then above 12.2 C.

If temperatures for the next decade 2010-2019 continue the downward trend of the 2000-2009 period then the cycle will be more pronounced (better defined).

I can do an update plot for anyone that’s interested.

http://www.climateconversation.wordshine.co.nz/2010/12/niwa-generating-warmth/

The record talked about there started at 1900. I had previously confused this with the 11SS but now know better thanks to Clarence.

What strikes me about the second (lower) plot 1900-1975 is that the raw data has a linear rise of +0.2 C/century. That’s very close to the +0.14 normal climate in the post above.

http://www.climateconversation.wordshine.co.nz/pics/nztr-niwa-adjust-nzcsc-977.jpg

And the upper plot of 1900-2008 showing +0.3 C/century in the raw data is not that far removed either.

http://www.climateconversation.wordshine.co.nz/pics/nztr-niwa-adjustment-1080.jpg