Is Global Warming (G.W.) to blame?

Mothman

Longfield wrote:

Quote:
Originally Posted by To_be_confirmed
There was something interesting on the farming frecast today. Rainfall amounts are up to 150% above average along the west coast, while the east coast had 35% of average rainfall in January (so far?). I wonder why the difference is so marked??



G.W. ..this is exactly what happens, eventually the west will dry out too..then NI then Scotland.

The west being wet and east dry this month is not a result of GW. Its come about as a result of a blocking high to our east which has generally been fending off the Atlantic fronts and scooting them up the west coast and on into Scotland.
Just down to synoptics.

As for this Island drying out, can't see any recent evidence of that during past 15 years or so. In fact relative to average(61-90), this decade (00-05) is wetter in the east (Dublin AP, Casement & Rosslare) by 9% and wetter in the west (Valentia, Belmullet, Shannon) by 4.4%

I've heard about the model predictions due to rising temps, but if models can't sort out the weather in one or two weeks time, what hope is there for models to predict during the next few decades?

Other things could through themselves in the pot.
Maybe the NAD will shut down, a major volcanic eruption...

Danno

I thought the 80s were the wettest decade? It felt that way!

How are the midlands (KK, Birr, Mullingar) fairing out? Are we wetter than before then aswell?

Supercell

Mothman wrote:

The west being wet and east dry this month is not a result of GW. Its come about as a result of a blocking high to our east which has generally been fending off the Atlantic fronts and scooting them up the west coast and on into Scotland.
Just down to synoptics.

What is weather if not synoptics?, its like saying you can drive a car faster on the motorway that a town centre because its a car..its not a valid statement to make.

Lets have a look at what is predicted to happen in a warming world in our little corner. (i'll provide evidance of this later including a paper written on climate change in Ireland).

1) In a warmer winter climate the azores high doesnt retreat as far back south as previously, leading to increased rainfall in Northwestern margins..read west coast Ireland, Northern counties and Scotland (till recently it was thought that it would retreat further in winter than it has this year - I believe this opinion will be revised by climatologists if not already by some) leading to increased rain fall in the British Isles and Ireland .

2) In the summer it moves further north steering the depression systems further out to the north and west giving places like Scandanavia a much wetter climate. Areas to the east and south will on average become drier, the more south and east you go -the more pronounced the effect.

Personally I feel that this year could well be the start of a trend where the azores high retreats much less further south than previously predicted giving us increased drying even in winter.

Ok now some stats

Just using Dublin Airports figures here (source http://www.cso.ie) as its a bit a pain in the bum working with the output from the site.

Long term average rainfall is 733mm per annum.

2000 - 840
2001 - 627
2002 - 1102
2003 - 643
2004 - 752
2005 - 683

One year there considerably above average the rest lower or close to average. Looking at the monthly data in recent years there has been many dry months and a couple of very wet months that have tended to sku the total back towards normal.. but I admit, looking at the annual overall picture isnt showing much change here in eastern Ireland - Yet!

Lets go a little further south and east to where the effects will be seen first.

Uk Rainfall Anomolys

2004

http://www.metoffice.com/climate/uk/2004/annual/maps/Rainfall_Anomaly%20No%20Stations.jpg
Note the location of the below average regions (80%)

Now move on to

2005

http://www.metoffice.com/climate/uk/2005/annual/maps/Rainfall_Anomaly%20No%20Stations.jpg
Note how the 80% line is far more visable, in fact only much above average regions are in Scotland, a trend I fully expect to be repeated in future years.

Climate predictions for Ireland.

Published paper from UCD (2000) - Climate Change In Ireland- Recent Trends In Temperature And Precipitation
http://www.ucd.ie/gsi/pdf/36-2/climate.pdf

Presentation from Jim McIlwee (powerpoint)

Climate Change and Areas Of Outstanding Natural Beauty

Both the studies predict increased winter rainfall based on the premise that the azores high retreats far enough to allow more active winter weather fronts (warmer air = more active as a rule of thumb) to pass over us - if the azores high doesnt retreat as far as projected..it stays dry.

Finally global temperature anomolies.

ftp://ftp.ncdc.noaa.gov/pub/data/anomalies/land_o_C.all
Open with notepad..think you will be suprised at just how persistant these anomolies are and how steadily their growth has being.

To deny global warming in the face of such evidance is to stick ones head in the sand.

I believe that modeling until recently has overcooked the retreat of the azores high in winter, thus imho even in winter there will be (eventually) reduced rainfall.

"G.W. ..this is exactly what happens, eventually the west will dry out too..then NI then Scotland."

Perhaps in Ireland this is a little bit of a stretch, but imho its already happening in the UK and only a matter of time till its here too..this year is year is the beginning of a long term trend I strongly believe.
In the end only nature will decide, climate isnt a matter of opinion, it will do whatever it likes, we can just measure it and try to extrapolate trends.

lucernarian

To_be_confirmed wrote:

There was something interesting on the farming frecast today. Rainfall amounts are up to 150% above average along the west coast, while the east coast had 35% of average rainfall in January (so far?). I wonder why the difference is so marked??

Why did I ask??:o There's a thread now to answer this bit of curiousity.

I don't like going into GW mainly because of my own, and frankly everyone else's, ignorance of the subject. No one can say with any certainty why the seas are that bit warmer. Could it be "just a phase"? Yet who can deny that there is much more CO2 in the air now and that it increased more quickly since industrialisation around the world took place?

There's too many unanswered questions.

Mothman

Danno wrote:

I thought the 80s were the wettest decade? It felt that way!

How are the midlands (KK, Birr, Mullingar) fairing out? Are we wetter than before then aswell?

Taking figures from 12 stations

60s 988mm
70s 920
80s 1004
90s 1033
00-05 983

The 60s may be slightly different (just a few mm) as Cork AP and Casement opened in 62 and 64 respectively.

As for the midland stations, 00-05 is exactly at the 61-90 mean.

Of course 4-5 decades is a very short sample time, but in the Climate Change for Ireland link provided by Longfield, there is a graph showing how the rainfall at Malin Head has risen from about 800mm in the late 1800s, to above 1100mm in the late 1900s.
I'm not sure whether this is for the same period, though I think it is, the rainfall in the SE has dropped, although the trend at Rosslare since the 60s is rising, and particularly so during past few years.

Supercell

Well we are at the short term edge (100 year trend) of the predictions, just like winter, a few hundred miles either way is a bumper snow year compaired to a no snow year.

I believe Portugal and Spain are already behind the 100 mile zone..and the SE of the UK isn't far behind, imho..it is proceeding faster than predicted.

Criky just looks at the sea ice to the north ..its just amazing whats happening

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/arctic.shade.jpg

I do readily admit the evidance is scant for major effects to be here in the NW of europe, I do believe our tipping point has been reached however and time will tell.

Mothman

Longfield wrote:

In the end only nature will decide, climate isnt a matter of opinion, it will do whatever it likes, we can just measure it and try to extrapolate trends.

I'm essentially in the same camp as TBC. Yes there is relative warming, but try telling that to eastern europeans at moment. Regardless of what warming takes place, I don't believe that the pattern of this winter will happen winter after winter. I don't think a corner has just been turned. I believe that there will be years, even decades to buck the trend. Maybe it'll be as a result of a massive volcanic eruption, sunspots etc,

As for this Island of which the NAD has such an influence, if the trend of slowing continues and it even stops or reverese somehow, then maybe its an ice age we're staring into and not the opposite.

As you can see I'm all over the place I don't have any firm ideas, there are a lot of ifs and buts.

Globally 98 has been the warmest year on record, with 97 the warmest in Ireland. I do wonder whether we're past a peak or just steadying for another lung upwards, and while I think it'll be the latter, I'm not concvinced, just like I'm not convinced that the past few months indicate that it is going to be dryer in the long term, so soon after 2002 which was wettest year on record across much of Ireland followed by 2003 which was dryest year on record at Birr.
With all the various opinions, someone has got to be right, and maybe Longfield you are, ....who knows?