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Archive for September, 2014

Czech-Canadian tree ring study

September 26, 2014 1 comment

This post is in honour of a great mind where I have more to say sometime.

The late Vít Klemeš who died 2010 gave a talk on July 12, 2007, in the HW2003 Workshop on Analysis of Variability in Hydrological Data Series, at the IAHS General Assembly in Perugia, Italy.

He concluded with a truism I believe in

The moral of my talk is this: The most fun and perhaps the greatest value of doing something is in doing it. The results may well go up in smoke, be wrong, become obsolete and forgotten, but some new ideas may have emerged in pursuing them, and some of them may somewhere, sometime, bear fruit. …”

They have, right now.

And that is Vít Klemeš. He had a sense of fun, sense of humour, yet enough is revealed in past writing showing he comes across as quietly subtle, a real technician, the lack of ego which comes with confidence.

This presentation is as a PDF at a moderate technical level which might seem somewhat wooden in places. It needs a degree of background knowledge, without this maybe there is enough.

 

 

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Categories: humour, Minder

Met Office, HadSST3, CRUTEM3, HadCRUT3, questions over gridded coverage

September 18, 2014 4 comments

Image

[update: I used an incorrect mix of datasets, see Talkshop thread here. Corrected PDF and now expanded to include HadCRUT4.

corrected PDF bundled in .zip (9.5MB) linked here HadCRUT3 and here  HadCRUT4]

The UK Met Office / Hadley Centre (Met Office) / Climatic Research Unit (UEA) construct and publish global time series for temperature based on published 5 degree gridded. How this is derived from land meteorological station readings and ship board for sea surface temperature is unclear. The gridded to eg. global is a simple (cosine) weighted average which takes into account the variable area of a linear grid representing a sphere.

I have put together maps showing the data counts for decades over a world shore outline. These are provided as vector plots (master work), PDF, or for casual looks, PNG. The results are disturbing and particularly in the light of the Met Office producing 100 different versions of HadSST3. “Each of the following files is a zip archive containing ten realisations of the HadSST3 data set. There are 100 realisations in total.”

Do I detect obfuscation, flapping for distraction?

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Categories: analysis, Datasets, temperature

The poor state of HadSST

September 11, 2014 Leave a comment

What follows is first art. I have yet to work out a better pictorial method. For now a tortured spreadsheet will do well enough.

You can just make out continental land masses…

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Met Office HadSST3 (Hadley centre Sea Surface Temperature version 3) total cell data counts for monthly 2005..2014 on published linear 5 degree latitude/longitude grid. Should be 115 counts in all sea grid cells. Click image for full size version.

Data: Met Office HadSST3

I’ve known for a number of years of the dreadful state of climatic datasets, HadSST being one of those but did not have the pictorial evidence. Period from 2005 is an arbitary choice arising during software development.

When I first looked at the gridded SST data, some time before 2010 I noticed what seemed to be a mix of monthly and annual in cells, with many missing data. It also looked very dubious on coastline handling. This was noted but nothing further done.

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