2010 was the Coldest year in 52 Years at Dublin Airport

Sponge Bob

A nice piece from the Irish Economy blog .

http://www.irisheconomy.ie/index.php/2010/12/31/%E2%80%9Cglobal-warming-linked-to-harsh-winters%E2%80%9D/

A longer term perspective is needed if we are to talk about “climate” as opposed to “weather”. In an earlier post I drew attention to absence of a positive trend in the Dublin’s annual average temperature over the period 1958 to 2008. Two more years of data have reinforced the main points I made in that contribution. In 2009 Dublin’s temperature was slightly below the long-term average, while 2010 was the coldest of the past 52 years, with an average temperature of 8.3º C - more than two standard deviations below the 1961-1991 average used by meteorologists to represent “the long run”. During last winter (December 2009 – February 2010) the average temperature was three standard deviations below the long-run winter average. It is very likely the winter of December 2010 – February 2011 will also be unusually cold.

Unusually feckin freezing more like There is more.

The warmest year of the past half century was in 1989. The average temperature during the naughties was lower than during the 1990s A longer term perspective is needed if we are to talk about “climate” as opposed to “weather”. The graph of Dublin’s annual average temperatures (below) does not convey an impression of a consistent upward trend in annual temperature since 1958. This is confirmed by standard statistical tests, which reveal that there has not been a significant trend (positive or negative) in the annual data over the entire 52-year period. Nor has there been a consistent trend in temperature in any of the four seasons. More detailed investigation shows that there was a significant positive trend for some 30-year windows between 1958 and 1993, but for all such windows between 1971 and 2010 the trend has been negative although not statistically significant. The trend in Winter and Summer temperatures has been negative but not significant since the 1970s. Similar graphs of Dublin’s rainfall reveal no significant trends.

And the author never even covered the thorny issue of increasing Urban Heat island effect at Dublin Airport which place hardly had any tarmac in 1958 compared to now....and nor did it have lots of warm avgas belchers contributing their daily blast of heat around then.

Were any corrections made for UHI the trend would most certainly have been more markedly downwards ....but raw uncorrected data is always good.

Mothman

The weather station at Dublin AP has been moved twice during past 20 years, with the current site colder than the previous sites.
I'd ignore long term stats at Dublin AP and look towards consistent sites such as Phoenix Park, though daily or up to date monthly data is not available online.

Deep Easterly

Mothman wrote: »

The weather station at Dublin AP has been moved twice during past 20 years, with the current site colder than the previous sites.
I'd ignore long term stats at Dublin AP and look towards consistent sites such as Phoenix Park, though daily or up to date monthly data is not available online.

Agree with you MM. I'd not trust the long-term data at Dublin Airport either because of all the shift arounds of the station.. I have also read that the new location is in a frost hollow as well but can't confirm this.

I'd rather deal with data from Valentia for a more reliable long-term overview. I have done up a quick chart showing the annual mean temperature at Valentia Observatory since 1940:



(inversions based around the 61-90 average)

The value for 2010 is only a guess of mine at this stage but I reckon the climatological average for the year will finish around 10.2c at the station, which would make it the coolest year since 1986, that is, 26 years.



Data souce: http://climexp.knmi.nl/selectdailyseries.cgi?someone@somewhere

Danno

Valentia ended up with 10.1c for 2010... http://www.met.ie/climate/monthly-data.asp?Num=305

It's own record low of -7.7c recorded in December is noteworthy too.

Mothman

I suggested Phoenix Park as the nearest alternative option to Dublin AP. There are very few sites with climatological record of more 100 years. Phoenix Park is one and of course Valentia

The effect of UHI (Urban heat island) will always be debated with regard to Phoenix Park despite the size of the park.

Elmer Blooker

Mothman wrote: »

The weather station at Dublin AP has been moved twice during past 20 years, with the current site colder than the previous sites.
I'd ignore long term stats at Dublin AP and look towards consistent sites such as Phoenix Park, though daily or up to date monthly data is not available online.

The Phoenix Park records began in 1855. It appears that Dec 2010 was only the third time that a sub zero month was recorded in the Dublin area. The other two occasions were December 1878 at -0.1c and January 1881 at -0.5c.
Interestingly no sub zero month was recorded in the 20th century - the closest being February 1947 at +0.7c and January 1963 at +0.4c.
Other near misses were Feb 1855 at 0.2c and Feb 1895 at 0.2c.
My information is from a battered old book I have called The Climate of Dublin.

M.T. Cranium

Dublin temperature anomaly seems to be fairly well correlated with the Central England temperature series (CET).

The updated data for 2010 show that in the CET, the year 2010 was the first below-9.0 year since 1986 and came within one tenth of a degree in the annual average (8.8 in 2010, 8.7 in 1986). The year 1985 was also around 8.8 to 8.9. This past year was about level with 1979, and then 1962 and 1963 were also a bit colder (8.6, 8.5).

So in context, you could say 2010 was about as cold as four or five other years in the past half century; all were reasonably close in the range of 0.3 colder to 0.1 warmer than 2010.

Also giving some context, the year 2010 was about as cold as the average for the first 50 years of the CET series, 1659-1708. The coldest years in that series are 6.8 deg in 1740, 7.2 in 1695, and 7.4 in 1879.

We should keep in mind that when we compare 2010 with the Maunder and other cold decades of the Little Ice Age, it is only the winter temperatures that have returned to values similar to those colder periods. The other three seasons remain closer to the average of the late 20th century warmer climate and have only dropped off slightly. On the CET index, the average anomaly relative to the long-term for all months March to November in 2007 to 2010 has been about +0.4 while for winters since 07-08 it has been -0.3. What we can conclude from all that, is that any long-term changes now underway have so far only made a significant impact on winter patterns and all we can say about the other seasons is that they have returned to near the very long-term average from a peak of warmth established around 1988-2006. Perhaps these are similar structural changes given how mild the winters were then, but when compared to colder climate intervals, so far only the winters have begun to approximate the average of those periods, the rest of the year remains more typical of the recent warmer climate.

compsys

Deep Easterly wrote: »

Agree with you MM. I'd not trust the long-term data at Dublin Airport either because of all the shift arounds of the station.. I have also read that the new location is in a frost hollow as well but can't confirm this.

I'd rather deal with data from Valentia for a more reliable long-term overview. I have done up a quick chart showing the annual mean temperature at Valentia Observatory since 1940:



(inversions based around the 61-90 average)

The value for 2010 is only a guess of mine at this stage but I reckon the climatological average for the year will finish around 10.2c at the station, which would make it the coolest year since 1986, that is, 26 years.



Data souce: http://climexp.knmi.nl/selectdailyseries.cgi?someone@somewhere

Dublin Airport has to be in some type of frost hollow. Some of the minimum temps recorded there are just way off the scale sometimes. I actually posted a discussion on this before under 'Dublin Airport's Micro Climate' because I was so surprised by it.

The unusually low temps at Dublin Airport are often recorded during both summer and winter. It's just strange. I'm interested in the weather (but no expert!) and would often look at the stats for the previous day's weather on the Met Eireann site. I've lost count of the number of times Dublin Airport would record an overnight minimum that was up to 5 or 6 degress colder than anywhere else in the country - even inland locations. It's seems particularly pronounced on calm, clear evenings.

Sponge Bob

Leaving aside the frost hollow effect.

http://www.met.ie/climate/monthly_summarys/dec10.pdf

the coldest December on record almost
everywhere. It was also the coldest of any month at Dublin Airport, Casement Aerodrome and Mullingar,
each with over 50 years of record. The lowest December air temperature ever measured in the country,
-17.5°C, was recorded at the climatological station of Straide, Co. Mayo, on the morning of the 25th, while
Casement Aerodrome’s minimum value of -15.7°C on the same day was the lowest value of any month ever
recorded in the Dublin area.

also

Lowest air temperature: -15.7°C at Casement Aerodrome on 25th (its lowest such value since temperature records began there in 1958)
Lowest grass minimum temperature: -17.3°C at Gurteen on 21st (the lowest such value for December in the country since 1961)

but it was not all bad news

Sunshine Highest monthly total: 91 hours at Valentia Observatory (its sunniest December since records began there in 1892)

DOCARCH

Mothman wrote: »

The weather station at Dublin AP has been moved twice during past 20 years, with the current site colder than the previous sites.
I'd ignore long term stats at Dublin AP and look towards consistent sites such as Phoenix Park, though daily or up to date monthly data is not available online.

I wouldn't take the Phoenix Park as 100% gospel either. That station is located in the Ordnance Survey and buildings over the years have been added/extended close to the obs site (to the NE) and in recent years a large single storey building was built approx. 5 metres to the SE of the obs site.

Mothman

DOCARCH wrote: »

I wouldn't take the Phoenix Park as 100% gospel either. That station is located in the Ordnance Survey and buildings over the years have been added/extended close to the obs site (to the NE) and in recent years a large single storey building was built approx. 5 metres to the SE of the obs site.

I assume 5m is not a typo
I have an official weather station. I think it sacrilege to not preserve a weather station site, especially one that has been operating for decades. Changing the environment around a station...it may as well have been moved.

Would you give a google map link to the Phoenix Park station?

DOCARCH

Try this link. You need to pan up a smidge.

http://maps.google.ie/maps?q=google+maps+ireland&ie=UTF8&hq=&hnear=Ireland&gl=ie&ll=53.3635,-6.349011&spn=0.001074,0.002406&t=h&z=19

5 metres approx. from the obs compound to the new building to the SE and that large building to the NE is probably 1950s/60s.

No respect!

Elmer Blooker

Casement's -15.7c (on xmas day) was the coldest ever recorded in the Dublin area but only by a fraction. The previous was -15.6c on Jan 25th 1881 - 130 years, amazing.
Here's some trivia which I find interesting, no extremes of temperature records were recorded in the winters of 46/7 or 62/3 but the winter before the BIG one (61/2) saw two records broken: -14.4 on Dec 31 1961 and -9.8 on March 4 1962

* we wont debate whether March is winter or spring.

Iancar29

Some very interesting posts on this page, fair play to all who posted.

Sponge Bob

Phoenix Park. This is the location bang on .

http://maps.osi.ie/publicviewer/#V1,709842,736095,7

The building is not there in 1995 ( click dates on right) but is there in 2000. The Google Pics are better, I know. You have to move a netch to see a white dot in the OSI photos.

If you then toggle 25" ( a map from around 1905) the "Observatory" was a tad further west of the current location. Toggling 6" ( a map from around Famine Times...say 1840) the the "Observatory" was a tad further south of the current location.

That would be 2 moves and a building to the north followed by a building to the south east.

That and the trees surrounding the site to the west appear to be second half of the 19th Century growth.

HTH

Iancar29

Sponge Bob wrote: »

Phoenix Park. This is the location bang on .

http://maps.osi.ie/publicviewer/#V1,709842,736095,7

The building is not there in 1995 ( click dates on right) but is there in 2000. The Google Pics are better, I know. You have to move a netch to see a white dot in the OSI photos.

If you then toggle 25" ( a map from around 1905) the "Observatory" was a tad further west of the current location. Toggling 6" ( a map from around Famine Times...say 1840) the the "Observatory" was a tad further south of the current location.

That would be 2 moves and a building to the north followed by a building to the south east.

That and the trees surrounding the site to the west appear to be second half of the 19th Century growth.

HTH

I persume those grounds arent open to the public?.... i go over regularly enough...

Mothman

Sponge Bob wrote: »

Phoenix Park. This is the location bang on .

http://maps.osi.ie/publicviewer/#V1,709842,736095,7

Was about post all the detail you given....thanks for saving me the effort

The numbers 1-8 can be used to toggle between views.

Danno

Look at page 16 here... http://www.met.ie/climate/monthlyBulletins/oct10_lores.pdf where 14 all-time low temperature records were broken and one more was tied. But of course they won't be shouting this from the rooftops just in case the general Joe Public objects to handing over the carbon tax. Shiver on Ireland, shiver on...

Elmer Blooker

Danno wrote: »

Look at page 16 here... http://www.met.ie/climate/monthlyBulletins/oct10_lores.pdf where 14 all-time low temperature records were broken and one more was tied. But of course they won't be shouting this from the rooftops just in case the general Joe Public objects to handing over the carbon tax. Shiver on Ireland, shiver on...

That's the October issue of the ME Monthly Weather Bulletin yet that list has December's record breaking temp in it.
Proof that ME does the best long range forecasts!

Danno

LOL!!! Well spotted Elmer, however there is a good explanation! There is such a volume of data from Observation Stations that have to be quality controlled resulting in around 8 to 10 weeks to compile the bulletin. The summary is usually out 3 to 5 days into the new month as they only glance over the familiar fifteen sypnotic stations.

By the time the October one was finished, the new records had been broken and reported into the Met, so they updated the final page before publishing. Thank God they did as we can now look at the most-up-to-date record of all time lows!

They published a similar list of all time max temp records in the September issue on page 16 also!

Sponge Bob

Interesting to see the "adjusted" Dublin Airport temperature. I will get to adjustments in a moment because they are scientifically absolutely necessary and correct...as long as we are dead clear on how the adjustments were made and by whom

The Irish economy blog article that started this thread off gives a temperature of 8.3c at Dublin Airport in 2010.

However the GISTEMP ( one of the main global warming temperature records) shows that the average temperature at Dublin Airport was 8.54c source = 1 from 2

Looking at the graph in source 2 ( 1 is the text data at bottom) we see that Dublin Airport goes all the way back to 1880. That is because Dublin Airport is an adjusted series as it must be because Dublin Airport ITSELF is only 60 or 70 years old and is adjusted for stations nearby which 'fill in' the record back beyond that . Phoenix Park must be part of that backfill ...somehow....it is the older continual record in Dublin.

We can further pick up RAW or Unadjusted data for Dublin Airport here

http://www.cso.ie/px/pxeirestat/Dialog/varval.asp?ma=MTM02&ti=Temperature+by+Meteorological+Weather+Station,+Month+and+Statistic&path=../Database/Eirestat/Weather%20and%20Climate/&lang=1

CSO Data (Unadjusted) + GISTemp ( adjusted ) 2010 , Jan - Sept only on CSO site. This to show that certain montsh are more adjusted than others

2010 Jan Feb Mar April May June July Aug Sep Dublin Airport Raw 1.9 2.4 5.3 7.9 9.9 14.4 16 14.3 13.3 Dublin Airport Adjusted 1.7 2.3 4.9 7.8 9.6 14.1 16 13.9 13.2

I personally have no idea who carried out the adjustment or when.

However many of the thorny issues with AGW models are that the necessary adjustments were made quite a few years ago and that nobody seems to know what they were any more....nor were the adjustments fully documented and peer reviewed.

This leads us to a massive row from 2010 called KIWIGATE concerning the 7 station series of the New Zealand Temperature Record. 7SS NZTR for short if you google. This has led to a great deal of peer review work being undertaken to CHECK the 7SS and no more than Dublin the weather stations moved around over time.

The peer review is still ongoing. Poeple would be interested in reading HOW they DID IT and WHY all the same. Here is the jump page for all 7 reviews

http://www.niwa.co.nz/news-and-publications/news/all/2009/nz-temp-record/review

Here is the Auckland Report from December 2010 . There really should be a similar analysis lying around somewhere for Phoenix Park and Dublin Airport.

http://www.niwa.co.nz/__data/assets/pdf_file/0011/108884/Auckland_CompositeTemperatureSeries_13Dec2010_FINAL.pdf