Archive for February, 2010

Solar dimming (con’td., 10Feb10)

February 10, 2010

Jean Oliviéri, a retired scientist from the Centre de Radiométrie of Carpentras (located in the Provence, at latitude 44.05°N) sent me a graph with total solar energy (in kWh/m2, always on a horizontal surface) from 1972 to 2009:

It is interesting to see a well defined dimming period from 1972 up to 1988, followed by an overall brightening. This brightening is not monotonically increasing: first there is an  interruption caused by the Pinatubo volcano eruption, and than a diminishing through the years 2005 to 2008. The 2009 solar energy is again on the rise.

For that 2005-2008 period we find a negative trend in all stations analysed so far:  Maastricht (NL, 50.5 °N), Trier (DE, 49.5°N), Diekirch (LU, 49.5°N), Findel (LU, 49.4°N) and Carpentras (FR, 44.1°N).  Trier and Findel readings are sunshine hours, taken as a proxy for total yearly solar energy. All stations also show (where available) a reversal of that trend in 2009.

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The Hockey Stick Illusion

February 4, 2010

I am very busy working on the Computarium attic so the investigations on a possible solar dimming  during the last years must be given a temporary break.  Suffice to say that I received a complete set of data from Carpentras (France) and that I searched the weatherstation of the Luxembourg ASTA organisations. The latter have what seems very poor pyranometer readings with frequent outliers as 14 Wm-2 during the night or 1300 Wm-2 during daytime, so I am not sure if this source will yield anything useful.

I managed to start reading the book of A.W Montford (better known as the blogger behind the Bishop Hill blog). It makes very interesting reading, and it is written in a agreeable “non-academic” prose.  To be recommended!

Update 13 March 2010:

Read this article The case against the hockey stick by Matt Ridley in Prospect: “Andrew Montford’s The Hockey Stick Illusion is one of the best science books in years”.
Having finished this outstanding and thrilling book, I agree.