Why Are Summers Getting Stormier?

[Pennine Ten Foot Drifts]

@Gray-Wolf: Did you look at the years 2012 was competing with for title of wettest AMJ on record? They are....

1782 336.7

1830 324.4

1797 313.1

IMO, the common factor is a period of low solar output that includes the Dalton Minimum.

It's very enlightening to have a look at the records for that time - you will see many of the wild swings in monthly figures that we have been experiencing recently.

Any influence from the Sun upon climate lags from one cycle to the next; any current impact will be from the previous cycle (23) the influence from this current much quieter cycle won't be felt for at least another 6 years, possibly 10.

Looking back through then history of solar cycles it appears we are in a similar period to the turn of the 20thC, and given that these recent record breaking extreme events include that time period it seems reasonable to me to think that there is more at work here than just solar input. Certainly I see no reason to discount solar input as one influencing factor, but equally I think it isn't sufficient to explain everything we are currently seeing. So the question to those who dismiss 'the elephant in the room' is what then are the 'other influencing factors' ???

Edited July 1, 2012 by Pennine Ten Foot Drifts

[Polar Maritime]

Here's some info on the Lockwood one:

http://news.bbc.co.uk/1/hi/8615789.stm

Can't remember the specifics on the other but it's been posted here before, will dig around tomorrow - perhaps in the Solar thread???

Here we go....http://arxiv.org/pdf/1202.1954v1.pdf

http://www.john-daly.com/solar/solar.htm

http://www.tmgnow.com/repository/solar/lassen1.html

Edited July 1, 2012 by Polar Maritime

[jethro]

Here we go....http://arxiv.org/pdf/1202.1954v1.pdf

http://www.john-daly...solar/solar.htm

http://www.tmgnow.co...ar/lassen1.html

Thank you. That's the one I was thinking of - you're a little star!

[BornFromTheVoid]

Cheers jethro and Polar Maritime.

A quick screen shot from the Solheim et al., paper shows this:

Correlations between SCL and 11 years average temperatures as function of

time lag after the mid time of the sunspot cycle.

This seems to indicate little or no lag time between the effect of a solar cycle on temperatures in the northern hemisphere and Europe. So we should be able to see the impact of the low solar cycle very soon methinks. I haven't read through every part of the study yet though...

This might be of interest to some

http://journals.amet.../2008JCLI2296.1

From the abstract;

The results show periods of relatively high dp(abs)24 and enhanced storminess

around 1900 and the early to mid-1990s, and a relatively quiescent period from about 1930 to the early

1960s, in keeping with earlier studies. There is little evidence that the mid- to late nineteenth century was

less stormy than the present, and there is no sign of a sustained enhanced storminess signal associated with

“global warming.†The results mark the first step of a project intending to improve on earlier work by

linking barometric pressure data from a wide network of stations with new gridded pressure and reanalysis

datasets, GCMs, and the NAOI. This work aims to provide much improved spatial and temporal coverage

of changes in European, Atlantic, and global storminess.

[Gray-Wolf]

Could I just add that the term 'Global Weirding' was coined in the last years of the noughties by teams looking at the weather patterns since 02' (where this study leaves off?) so we need to be open to the papers, now in the offing, covering the period we are now discussing?

To me the onset of the 'Arctic Amplification' is observed from 02' onwards (Kara/Barentsz) with wider impacts being measured each Autumn/early winter since with the Beaufort sea area being the last (I am aware of?) to be included.

As with Arctic ice loss itself this is a fast evolving subject area and, by the looks of the current melt season, will continue to be so?

Edited July 1, 2012 by Gray-Wolf

[phil nw.]

There`s certainly been a change in the N.Hemispheric Sypnotic patterns in Summer since the turn of the Century-at least on our side of the pole anyway.

I posted these reanalysis charts recently in the Summer discussion thread and in case anyone has not seen these i think they tell the story of why our more recent Summers have been so unsettled.

Anyway i had a search on the NOAA site and looked at the Northern Hemisphere 500hPa anomolies for the Summer months only( June-August) and the zonal wind anomoilies for the same season going back to 1994.

I have split the results into 3 batches of 6 seasons and you can see for yourselves the differences in these amnomalities as we go through the period 1994 to last year.

First the 3 500hPa charts.

and now the 3 Zonal winds anomalities.for the same 3 periods

We can see from those charts how, over the last 18 years,the areas of yellow( higher pressure) has disappeared from NW Europe and in the last few Summers the UK has been dominated by lower -blue-anomolies.

Notice too how we have greater heights over the Arctic now and when you look at the earlier chart you can see the big difference with the blues(low pressure) over the Arctic before the Millenium.

Likewise see how the mean Zonal wind(westerly winds) anomalies have moved south to be over our latitude.

One final chart- the latest data for June- and it seems this pattern continues into Summer 2012.

This is only a limited analyisis over a relatively short period and doesn`t mean we are in for many years of poor Summers.

It is,however, interesting. from the pov of showing the Upper Air Sypnotics behind the relatively recent run of poor Summers and that there is evidence out there to show that the jet stream has been running on a more southerly track in recent Summers.

[Keraunic]

Well they are certainly not stormier in EA. I wish! The best storms I've ever experienced were in my home town/city of York. I moved here (Norwich) in 2001 and there's been very few really good storms since then.