A paper with the title 'Arctic sea ice reduction and European cold winters in CMIP5 climate change experiments' by Shuting Yang and Jens H. Christensen is about to be published in GEOPHYSICAL RESEARCH LETTERS.
In this paper the authors argue that the melting of Arctic ice will temporarily tend to bring about colder winters in Europe.
On _http://www.dmi.dk/dmi/smeltet_arktisk_havis_giver_kolde_vintre_i_europa they write that while there used to be five cold winters for each 30 year period, they expect us to have three to four cold winters per 30 year period until 2012.
It is mentioned that in a cold Arctic atmosphere the cold air from the upper layers sinks down continuously giving rise to a higher pressure than when the atmosphere is less cold as is the case over the areas of the Arctic sea where the ice has melted. The result is that the pressure differences between Europe and the Arctic areas are less, leading to a situation where the low pressure system take a more Southern route. Since the low pressure systems are responsible for bringing in air heated over the Atlantic ocean then the consequence should be that we will continue to experience cold winters in Europe even though ice disappears over the Arctic.
In the article it is mentioned that the winters 2005/2006, 2009/2010 and 2010/2011 were cold.
I have tried to work on the probabilities of the hypotheses that three to five winters will be cold during a 30 year period using a 5% threshold at either end of the spectrum. I used the binomial distribution function in excel. I don't know exactly how professionals do, but maybe other forum members can explain.
The hypothesis that there will be on the average three cold winters out of 30 has to be rejected if there is either no cold winters at all in a 30 year period or if there are seven or more cold winters.
What this means is that the chance of having no cold winter at all is less than 5 % if it is true that three winters out of 30 on the average will be cold. Similarly there is less than a 5 % chance that we will get seven or more cold winters if it is true that on the average only three out of 30 winters are cold. For the other possibilities the same explanations can be given only with different figures.
The hypothesis that there will be on the average four cold winters out of 30 has to be rejected if there is either no cold winters at all in a 30 year period or if there are eight or more cold winters.
The hypothesis that there will be on the average five cold winters out of 30 has to be rejected if there is either one or no cold winter at all in a 30 year period or if there are nine or more cold winters.
With these figures it seems that we may freeze quite a bit before climate models get seriously changed.
In this paper the authors argue that the melting of Arctic ice will temporarily tend to bring about colder winters in Europe.
_http://www.agu.org/pubs/crossref/pip/2012GL053338.shtml said:
On _http://www.dmi.dk/dmi/smeltet_arktisk_havis_giver_kolde_vintre_i_europa they write that while there used to be five cold winters for each 30 year period, they expect us to have three to four cold winters per 30 year period until 2012.
It is mentioned that in a cold Arctic atmosphere the cold air from the upper layers sinks down continuously giving rise to a higher pressure than when the atmosphere is less cold as is the case over the areas of the Arctic sea where the ice has melted. The result is that the pressure differences between Europe and the Arctic areas are less, leading to a situation where the low pressure system take a more Southern route. Since the low pressure systems are responsible for bringing in air heated over the Atlantic ocean then the consequence should be that we will continue to experience cold winters in Europe even though ice disappears over the Arctic.
In the article it is mentioned that the winters 2005/2006, 2009/2010 and 2010/2011 were cold.
I have tried to work on the probabilities of the hypotheses that three to five winters will be cold during a 30 year period using a 5% threshold at either end of the spectrum. I used the binomial distribution function in excel. I don't know exactly how professionals do, but maybe other forum members can explain.
The hypothesis that there will be on the average three cold winters out of 30 has to be rejected if there is either no cold winters at all in a 30 year period or if there are seven or more cold winters.
What this means is that the chance of having no cold winter at all is less than 5 % if it is true that three winters out of 30 on the average will be cold. Similarly there is less than a 5 % chance that we will get seven or more cold winters if it is true that on the average only three out of 30 winters are cold. For the other possibilities the same explanations can be given only with different figures.
The hypothesis that there will be on the average four cold winters out of 30 has to be rejected if there is either no cold winters at all in a 30 year period or if there are eight or more cold winters.
The hypothesis that there will be on the average five cold winters out of 30 has to be rejected if there is either one or no cold winter at all in a 30 year period or if there are nine or more cold winters.
With these figures it seems that we may freeze quite a bit before climate models get seriously changed.
