What can we expect from future winters in Europe & UK ( also USA, Canada, North America, Far East & Asia ) ?

1) Apparently there is now a trend towards more cold and snowy winters with snowstorms.
Seven out of the previous nine winters were snowy and cold ( across the Eastern United States and Eurasia )

2) Whenever we will have mild winters ( the ones we are used to ) they will increasingly come with rain and flooding.
This because of increasing concentrations in the atmosphere of carbon dioxide and consequent heating up of about all of the global oceans and the consequent melting of floating ice ( melting sea ice ), the air that originates from above the warmer oceans is every time warmer and containing more humidity ( causing more rain or snow especially where colliding with colder landmasses ).

Why is it that during global warming we are getting more cold and snowy winters?

a) Because of global warming and especially because of warming seawater the floating arctic sea ice is melting.
The now uncovered hot seawater will a ) evaporate much more and increase the humidity of the air above the open sea and b) continuously lose its heat to the air above it and so the sea water ( surface ) will cool down much faster as well.

The evaporation of the newly created humidity above the ocean will use energy and bring temperature of the air down.

At some point the humid air above the sea will cool down ( also relatively to air above waters more south that did not cool so much ).

( Ice contains air bubbles and is a good isolator and will prevent cooling down of the water )

Floating ice seals off perfectly the air from the water and limits evaporation of the seawater.

Ultimately this massive moistening ( and further cooling ) of the air above the northerly oceans creates a huge high pressure area
( with its center (peak) above Greenland, because Greenland is even colder ).

This high pressure can cause clear skies that with long night and very fable winter sun will further cool down water and the air above it..

This huge high pressure area ( with its peak centered above Greenland ) will prevent and block hot and humid air from the Azores & subtropical oceans (high pressure areas) to overflow and heat Europe ( as were are used to before the melting of the ice ).

Above all this, round this high pressure area ( as always in the Northern hemisphere ) the winds turn clockwise ( to the right side of Greenland this means pushing arctic winds down from the Arctic towards Europe ) pushing in arctic cold air to UK and Europe
( and the east side of the Rockies in the case of the United States )
( picking up humidity from the now open seas and delivering them as snow or snowstorm )
( and at the same time pushing further back the warm air ) .

Cool air is able to create a high pressure area that is more intense than typical summer high pressure areas.
On mainland Greenland there is no seawater to heat the air and in addition the snow reflects the weak sun resulting in very low temperatures with an even more intense high pressure area above Greenland as a result.

b) More snow in Greenland, Siberia and the North of Russia ( because of more humidity in the air because of warmer, more evaporating and oceans not covered any more by ice ) reflects sun and isolates possible heat from the earth, creating once more a cool high pressure area again preventing warm and humid air from the Azores & subtropical oceans to overflow Europe with warm and humid air
( in other words : preventing the warm jet stream or preventing the Westerlies to overflow Europe with tropical heat )
( During these periods of "weakening westerlies" the cold weather from the north once again moves in with the help of the clockwise rotation around the hudge high pressure zones ) ( diversion of the jet-stream or the jetstream is diverted ).
Apart from the cold arctic air also cold air from Siberia spills south into East Asia and even southwestward into Europe.

The jet stream, instead of flowing predominantly west to east as usual ( and bringing warm and humid air to North Europe ), meanders around the high pressure areas bringing down arctic air and becoming weaker at the same time ( because of resistance from the Greenland block ).

On the left side of the high pressure areas the jet stream is pushing north the warm and humid air from the Azores & subtropical oceans highs pressure areas this time to places as Alaska and Greenland causing more snowfall, more reflection and isolation, more cooling of the air and thus more high pressure above Greenland and Siberia).

North Atlantic Oscillation ( NAO ), low solar intensity ( last years - The most recent "solar minimum" occurred in December 2008) together with intense la Nina ( this year 2010-2011 ) possibly has helped to build up this last cold winters but have not such a big correlation with it as the melting of the ice.

Most probably this trend to colder and more snowy winters was just temporarily interrupted because of this very low solar activity
( which allowed the ice sheet to temporarily restore above arctic seas weakening the Greenland block and fortifying again the Westerlies ).

Now solar activity is increasing to normal values again ( remember the recent solar flares from sunspots ) together with the further increased carbon dioxine concentrations ( actually 3% or more increment a year coming from 1 % before ) in the atmosphere again increasing global warming, consequent further ice melting and re-activating and possibly further intensifying the trend to the cold and snowy winters described above.

Summary :

Just 10.000 years ago ( that is only five times the time since Jesus Christ) Europe was submerged in a very prolonged cold ice age.
This is the extreme.

But cold winters ( even in times of global warming ) in fact is the normal situation, since the geographical position of Europe is in fact very high
( or close to the Arctic and not so different from the geographical altitude of for example Siberia with its extreme cold winters ).

The mild European winters we were used to in fact are caused by a unique, complex, relatively small scaled and thus vulnerable combination of factors like a) a unique Gulf stream bringing tropical seawater in our direction over great distances in combination with b) the subsequent hot air above it being driven further over Europe by a strong jet stream ( undisturbed by large high pressure areas as now sometimes is the case ) and at the same time holding back arctic cold high pressure areas in the arctic.

Recently high pressure zones and snow ( Siberia, North Russia and Greenland ) act together to prevent the warm subtropical air from reaching Europe and are calling in cold Arctic air instead ( no confirmation of the Gulf stream slowing down although a slowing down of the Gulf stream would cause pretty much the same cold winters or in fact would only add up to it ).

Not saying at all that the ice ages will return ( because such an extreme would simply not fit with global warming at this point ) but saying that cold and snowy winters in some particular locations of the world ( like UK, Europe and parts of Canada and USA ) are not strange at all at these respective geographical high latitudes (close to the arctic) and that instead mild winters in this regions are in fact an exceptional phenomenon and only kept in place as long as all the necessary factors are perfectly in place.

It is however possible that a cold winter situation that until recently only occurred let us say every five years now already became a normality.

Arctic sea ice has been in retreat over recent decades, with record lows recorded in September 2007.
The normal recovery of the sea ice during winter has also been affected, especially in the Barents and Kara seas which have seen significant losses of ice cover over the past decade.

Stefan Rahmstorf, professor of physics of the oceans at the Potsdam Institute, said the floating sea ice in winter insulates the relatively warm seawater from the bitterly cold temperatures of the air above it, which can be around -20C or -30C.

“The Arctic sea ice is shrinking and at the moment it is at a record low for mid-to-late December, which provides a big heat source for the atmosphere,” Professor Rahmstorf said.
“The open ocean actually heats the atmosphere above because the ocean in the Arctic is about 0C, and that’s much warmer than the atmosphere about it.
This is a massive change compared with an ice-covered ocean, where the ice operates like a lid.
You don’t get that heating from below.

“The model simulations show that, when you don’t get ice on the Barents and Kara seas, that promotes the formation of a high-pressure system there, and, because the airflow is clockwise around the high, it brings cold, polar air right into Europe, which leads to cold conditions here while it is unusually warm elsewhere, especially in the Arctic,” he explained.

The scientists emphasised that the climate is complex and there were other factors at play.
It is, they said, too early to be sure if the past two cold winters are due to the ice-free Arctic.

“I want to be cautious, but basically in the past couple of months the sea ice cover has been low and so, according to the model simulations, that would encourage this kind of weather pattern,” Professor Rahmstorf said.

“The last winter of 2009-10 turned out to be fitting that pattern very well, and perhaps this winter as well, so that is three data points.
I would say it’s not definite confirmation of the mechanism, but it certainly fits the pattern,” he said.

http://www.independent.co.uk/news/science/expect-more-extreme-winters-thanks-to-global-warming-say-scientists-2168418.html

But the path of the jet stream, like this year, can wander, meaning the mild weather systems are not being brought to the UK ( note : and Europe ) in the same way.

http://www.bbc.co.uk/news/mobile/magazine-12045464

 

Ozone depletion

From Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Ozone_depletion
...
Ozone depletion also explains much of the observed reduction in stratospheric and upper tropospheric temperatures.
The source of the warmth of the stratosphere is the absorption of UV radiation by ozone, hence reduced ozone leads to cooling.

Some stratospheric cooling is also predicted from increases in greenhouse gases such as CO2; however the ozone-induced cooling appears to be dominant.
...

see also | Ozone hole Europe |