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Archive for the ‘Datasets’ Category

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.

Read more…

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Global temperature map comparison

May 4, 2015 7 comments
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UAH TLT V6 beta, click for larger

This new work showcases one month available for all datasets, February 2015. The image above, lower troposphere from UAH V6 beta is merely a picture, the true work is in a PDF for local display. The intent is information, not hitting you in the face, so whilst as such green is a colour few people like that is how it has turned out. New geographic map, new colours.

Combined images, PDF (2.9MB), the cover page explains more.

I leave the reader to draw conclusions. As I get accused, understating, some surprises are inside.

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Fast tidal data facility, UNESCO / IOC

January 3, 2015 Leave a comment

A couple of days I spotted a data event worth following up but I needed high resolution tidal data, difficult to find.

Image

UNESCO / IOC have created a facility directly linked to many (768 listed) tidal gauges provided true high resolution data, such as 15 minute and with a record of up to 30 days.

The intent seems to be providing public data for safety and research, such as Tsunami monitoring.

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Categories: Datasets, sea level

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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Met Office reports of day extremes 2013

December 2, 2013 Leave a comment

Over much of 2013 I have been collecting the extremes for a day as reported by the UK Met Office. April up to 1st December.

Example as copied

24 hours ending 2100 on 1 Dec 2013:UK
Highest max 0900-2100 11.7 °C Gt Cumbrae Millport
Lowest max 0900-2100 5.1 °C Okehampton
Lowest min 2100-0900 -4.1 °C Exeter Airport
Highest rainfall 2100-2100 3.2 mm Cluanie Inn
Sunniest 2100-2100 6.8 hours Wittering
Last updated: 2302 on Sun 1 Dec 2013

This might be useful / of interest to a few people so I have processed the information into a flat field spreadsheet form. I considered full Normal form but lets keep things simple, I’ve done the hard part.

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Categories: Datasets, weather

Demonstration of fractional delay function on real data

November 13, 2013 1 comment
Image

Figure 1

The meteorological station at Armagh Observatory, Northern Ireland closed in 2000[1]. A lot of the data has been made online access via scanned logbooks and some digitised data, paid for primarily by lottery funds.

An unpublished version of the data is used as part of a fractional delay demonstration.

Earlier article providing a template and instructions is
https://daedalearth.wordpress.com/2013/11/12/fractional-dataset-delay-subsample-resolution-in-a-spreadsheet/

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JAXA/EORC: El Nino Watch

July 16, 2013 Leave a comment

 

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Although El Nino is not a particular interest of mine JAXA have a new web page which I think is good.

Click the image or follow this link.

The web server might be fairly slow responding if my experience from the UK is representative, no big deal. This might be because a lot of images are rendered and loaded before the page displays.

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Categories: Datasets, temperature

Provisional look at solar constant 1923 to 1954

June 28, 2013 Leave a comment

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Figure 1, daily data. Note [1]

The solar constant has long been of interest to science, with good measurements in existence for over a century. Today and measured from satellite this is known as TSI (Total Solar Irradiance), but presumably there will be a slight difference between space based measurements and terrestrial measurements caused by irradiance wavelengths which are totally blocked by the atmosphere and cannot be deduced. Far UV probably being an instance. However this might be of little importance since parasitic irradiance from eg. high atmosphere Ozone which will see far UV might fill in within bandwidth.

1. A single data point is present 1957 which is probably a dataset error in original transcription.

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Categories: Datasets, solar

Graphline, extract data from a plot

March 30, 2012 Leave a comment

graphline-demo

A little while ago I needed to extract data from a plot but no tool I could find actually worked on awkward data, quite a common problem. Read more…

Categories: Datasets, software