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Hadley long precipitation series, report for July 2015

August 9, 2015 Leave a comment

Occasionally I might post this result, very unlikely anything significant will change, I might though rework something

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HadEWP, England and Wales precipitation since 1766, a very long series processed to z-score and less annual variation.

July 2015 was just above zero score. Other series plotted, Scotland and NI were damp, around 1 SD above zero.

All 11 plots bundled are here (PDF 11 pages, 1.6MB)

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Categories: analysis, weather

Images of the 1998 El Niño in world temperature maps

May 5, 2015 3 comments

A reader asked for a time representation… a tricky problem via a web site, the data is large…

Here are three different views, two from the UK Met Office and one from UAH, the newly released version. These run from January 1996 through December 2000.

Firstly here is an overview an Hovmoller plot for the same time span. These are widely used but rarely for earth whole views. Here are some I prepared earlier as a 2012 article (includes [2]) elsewhere which might help understanding on what I am doing for this article.Image

Figure 1, Hovmoller diagram of 1998 El Nino, UAH TLT V5.6 [1] (as PDF 142kB)

The 1998 El Niño event was similar to the less known ~1876 event, both seeming increasingly muted in the Met Office data. The El Niño form is a pulse of warmth primarily in tropical regions followed by a cool period. The warmth gradually disappearing apparently flowing poleward, producing a characteristic sideways V shape in Hovmoller graphics. The cool in inside the V. Perhaps preceeded by coolish. This pattern has repeated over the years.

Unfold

If instead of folding all longitudes into a mean as above a plain XY map for a month gives a different view, so we may be able to see from where on the globe there are contributions.

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A novel presentation of 177 UK meterorological sites

April 26, 2015 7 comments

This is a large work where I am dismayed at having a choice forced by inaction of others between junking the work or showing known defective data which precludes much in the way of worthwhile further analysis.

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Here is a 180 page document containing frequency plots for all 177 Met Office Datapoint site’s hourly data since July 2014. In addition geographic linkage is provided by location maps for each site and live links to public aerial images where known.

Document link, PDF 11.3MB

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Categories: analysis, weather

Annual report on GFS GCM performance

January 30, 2015 Leave a comment

A mailing list I receive from UCAR brought news of an addition to the GFS forecast archive “New Dataset: NCEP GFS 0.25 Degree Global Forecast Grids Historical Archive” and links to a web page.

On browsing an excellent general interest snippet appeared

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Page 16/17, performance over time for a few parameters of various GCM and with the observation on the GFS useful horizon “Increase is about one day per decade”.

Review of GFS Forecast Skills in 2013
Fanglin Yang
IMSG – Environmental Modeling Center
National Centers for Environmental Prediction

Link is on the performance review page, 2013 rev. is PDF (2.7MB)

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Categories: analysis, Modelling, weather

A real world demonstration of cloud controlling radiation

December 7, 2014 Leave a comment

The original text struck me as inappropriate so I’ve edited it. I put it down to being overtired. The original is archived if anyone wants to see it, just ask (there is a contact form), no questions asked on why.

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This is a huge plot including hourly data from WMO3768 Farnborough, England, a synoptic Met Office station where I estimate the site meets WMO 2010 recommendation Class 1, although the presence of a triangular airfield runway layout surrounding the station will have some side effects.

A details view of the plot is only practical via PDF (201kB)  Very likely the PDF will open looking as above so you need to set magnification and scroll around the plot, 100% is the intended view. Some details of interest are reproduced below at a normal scale.

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Categories: analysis, temperature, weather

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

September 18, 2014 4 comments

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[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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August 2014 radiative cooling East Anglia, Northern Ireland, South Midlands

August 30, 2014 1 comment

August 2014 there was a meteorological gift of both exceptional conditions and good data. What can be learnt?

Three Met Office sites showed a signature of exponential cooling. This requires clear sky and a calm. Given somewhat limited parameter hourly data the following shows the commonality. The computed terminal conditions are shown later in this article.

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Benson and Santon Downham data has been normalised to Katesbridge[3], which has the least noisy data or the three.

Achieving a close overlay requires taking earth rotation into account, dusk and dawn move relatively both by geographic location and the peculiar movement throughout the year as night length changes, these do not move together [1]. Fractional delay (less that the sample period) was used to equalize diurnal time. (see the two blog articles here)

Dusk appears to be the important factor, a surprising finding, I assume cooling is time from dusk, dawn terminates cooling.

General information, under essentially calm conditions wind drops for a period during the night then reappears just after dawn. (not shown here)

Temperature normalisation defined is for the cold period, not as accurate for Benson where the better site exposure (more open) led to more wind at times.

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Categories: analysis, temperature, weather

More Luling

June 30, 2014 Leave a comment

Following on from yesterday where Paul Homewood picked up on a comment I made on his blog see Luling Keeps Changing June 29, 2014, I took a look today at the NCDC data.

Maybe I picked up the wrong files, seems surreal.

I am now going to be precise step by step.

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Categories: analysis, temperature

Luling, Texas weather station

June 28, 2014 1 comment

A recent saga started by Paul Homewood over apparently excessive “homogenisation” for one of a vast number of US volunteer run weather stations led me to take a look. I’ll link Paul’s blog articles as an appendix.

The station is at Luling Foundation Farm, an agricultural station set up prior to WWII. The weather data runs from 1949.

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Luling station house looking south

They have a good web site which gives a history, starting the unravelling of the situation. http://lulingfoundation.org/our-history

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Categories: analysis, weather