ARCTIC OSCILLATION GLOBAL CLIMATE INFLUENCER by James Rohman | February 2014 Figure 1. A satellite image of the jet stream. Figure 2. How the jet stream/Arctic Oscillation might affect weather distribution in the Northern Hemisphere. Arctic Oscillation Introduction (%2#4)#)3(/-%4/!3%-)0%2-!.%.4,/702%3352%#)2#5,!4)/. (%2%!2%!.5-"%2/&2%#522).'#,)-!4%%6%.434(!4)-0!#44(%',/"!, +./7.!34(%0/,!26/24%8(!46/24%8)3).#/.34!.4/00/3)4)/.4/!.$ $)342)"54)/./&7%!4(%20!44%2.3.%/&4(%-/2%3)'.)&)#!.4#,)-!4%).$%8%3&/2 4(%2%&/2%2%02%3%.43/00/3).'02%3352%4/4(%7%!4(%20!44%2.3/&4(% 4(%/24(%2.%-)30(%2%)34(%2#4)#3#),,!4)/. ./24(%2.-)$$,%,!4)45$%3)%./24(%2./24(-%2)#!52/0%!.$3)! ).$)#!4%34(%$)&&%2%.#%).3%!,%6%,02%3352%"%47%%.4(% (%2#4)#3#),,!4)/.-%!352%34(%6!2)!4)/.).4(% /24(/,%!.$4(%./24(%2.-)$,!4)45$%34)-0!#437%!4(%2 342%.'4().4%.3)49!.$3):%/&4(%*%4342%!-!3)4%80!.$3 0!44%2.3).4(%/24(%2.%-)30(%2%4(2/5'(4(%0/3)4)6%!.$.%'!4)6% #/.42!#43!.$!,4%23)433(!0%4)3-%!352%$"93%!02%3352% 0(!3%3/&4(%#9#,% !./-!,)%3%)4(%20/3)4)6%/2.%'!4)6%!.$"9/00/3).'!./-!,)%3.%'!4)6% / / /20/3)4)6%).,!4)45$%3(%,03$%&).%4(% %842% -%3/&4(%%##%.42)#)4)%3).4(%*%4 342%!- (%.4(%2%)3!342/.'.%'!4)6%0(!3%4(%*%4342%!-3,/73 52).'4(%;.%'!4)6%0(!3%</&3%!,%6%,02%3352%)3()'().4(% $/7.!.$4!+%3,!2'%-%!.$%2).',//0352).'0/3)4)6%0(!3%34(%*%4 2#4)#7(),%,/73%!,%6%,02%3352%$%6%,/03).4(%./24(%2. 342%!-7),,-!).4!).!342!)'(4%2%!347%34/2)%.4!4)/. -)$$,%,!4)45$%3.4(%/4(%2(!.$$52).';0/3)4)6%0(!3%<()'( 3%%!#!,%563%,40(2%%3*%34532%42%$!%-6%-,/!023+3).4(4(%%".//52.4($%!22.9-"%)$47$%,%%.,!#4)/45,$$%32#4)# !.)2$4/3%4(!%,%.6/%2,4(02!%.3$3572!%2-)3,3/57"4)2./04()#%!,!2#)24)#4/4(%3/54( 5.$%234!.$).'4(%,/#!4)/.342%.'4(!.$-/6%-%.4/&4(%*%4 2!-%3!.3%.!#,)-!4/,/')34$%3#2)"%34(53 342%!-)3)-0%2!4)6% ! (%$)&&%2%.#%3).4(%3(!0%/&4(%*%4342%!-!.$$)342)"54)/./&#/,$!.$ 7!2-!)2-!33%3$52).'0/3)4)6%!.$.%'!4)6%0(!3%3)3!$2)6).' #/-0/.%.4).6!2)!"),)49/&%842%-%7%!4(%2).4(%/24(%2.%-)30(%2% 490)#!,,9!"/6% ()30!0%23%%+34/).42/$5#%4(%'%.%2!,2%!$%24/4(%2#4)#3#),,!4)/.(/7 )47/2+3(/7)4)3"%).')-0!#4%$"9 #,)-!4%#(!.'%!.$7(!4/00/245.)4)%3 "!.$4(2%!43$%2)6%&2/-4(/3%$%6%,/0-%.43 Why is it important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lobal Climate Influencer | Arctic Oscillation 1 1 1 Arctic Oscillation Arctic Oscillation (%2#4)#)3(/-%4/!3%-)0%2-!.%.4,/702%3352%#)2#5,!4)/. +.(/%7.2!#43)#4()3%(0//-,!%264//2!4%38%(!46/24%8)3).#/.34!.4/00/3)4)/.4/!.$-)0%2-!.%.4,/702%3352%#)2#5,!4)/. 4(%2%&/2%2%02%3%.43/00/3).'02%3352%4/4(%7%!4(%20!44%2.3/&4(%+./7.!34(%0/,!26/24%8(!46/24%8)3).#/.34!.4/00/3)4)/.4/!.$ .4(%2%&/2%2%02%3%.43/00/3).'02%3352%4/4(%7%!4(%20!44%2.3/&4(%/24(%2.-)$$,%,!4)45$%3)%./24(%2./24(-%2)#!52/0%!.$3)! ./24(%2.-)$$,%,!4)45$%3)%./24(%2./24(-%2)#!52/0%!.$3)! (%2#4)#3#),,!4)/.-%!352%34(%6!2)!4)/.).4(% 34(2%%.'24(#4)#).4%3.#3)),4,!94!)/..$3):%/-&%4!(3%5*2%%43344(2%!6-!2!)!34))/4.%8).0!4(.%$3 #3/42.%4.2!'#4(43!)..4$%.!3,)44%923!.)4$333)(:!%0/%&4)3-%!352%$"94(%*%4342%!-!3%!3)402%3352%%80!.$3 !./-!,)%3%)4(%20/3)4)6%/2.%'!4)6%!.$"9/00/3).'!./-!,)%3.%'!4)6%#/.42!#43!.$!,4%23)433(!0%4)3-%!352%$"93%!02%3352% /20/3)4)6%).,!4)45$%3!./-!,)%3%)4(%20/3)4)6%/2.%'!4)6%!.$"9/00/3).'!./-!,)%3.%'!4)6% / / /20/3)4)6%).,!4)45$%3 / / 52).'4(%;.%'!4)6%0(!3%</&3%!,%6%,02%3352%)3()'().4(% 52).'4(%2#4)#7(;).,%%',/!74)63%%!0(,!%36%<,/&02%33532%%!$,%6%,/0023%3).354(2%%).3/(2)4'((%2)..4(% -)2$#$4),#%,7!(4))4,5%$,%/37.4(%/4(%2(!.$$52).'3%!,%6%,02%3352%$%6%,/;03/3)).4)64(%%0.(/!234%(<%2(.)'( 3-%)!$$,%,%6%,!,40)425%$3%335.4(%/4(%2(!.$$52).'2%$%6%,/03).4(%./24(%2.;0-/3)$)4$)6,%%,0!(4)!453$%%<3()'( !3.%$!3,%%6!%,,%062%%,30325%23%3$5%2%6%)3,/,0/37).).4(4(%%./22#4(4)%#2.-)$$,%,!4)45$%3 !.$3%!,%6%,02%3352%)3,/7).4(%2#4)# 2!-%3!.3%.!#,)-!4/,/')34$%3#2)"%34(53 2!-%3!.3%.!#,)-!4/,/')34$%3#2)"%34(53 ! ! " " Why is it important? Why is it important? /70/,!2!)202%3352%4%.$34/+%%0&2%%:).'2#4)#!)2 #//.74!0)./%,!$2!!")2/06%2%43(3%52%2#4%4).#$3)24/#,%+%%70()&,2%%%(:)').('0/,2!#24)#!)!2)022%3352% !#,/,/.74!3).-%/$2%!"//&64%(!4(4%&2)'2)#$4)!#)24)/2#3,%%%70(3)/,%54(()').(4/0/,!/224!()20-2%32)3#5!2% !!.,,$/7352-!/3)2!%/ &4(!4&2)')$!)24/3%%03/54().4//24(-%2)#! !.$52!3)! (%,/#!4)/.!.$342%.'4(/&4(%2#4)#3%!,%6%,02%3352%!./-!,9 ).&,5%.#%3(%,/#!4)/.!.$342%.'4(/&7%!4(%20!44%2.3).4(%4(%2#4)#/24(%2.3%!,%6%,02%3352%!./-!,9%-)30(%2%7(%2%$%.3% 0/05,!4).&,5%.#%3)/.37%!4(%20!44%2.3).4(%!.$(%!6),9).352%$6!,5%/24(%2.2%3)$%%-)30(%2% 7(%2%$%.3% 0/05,!4)/.3!.$(%!6),9).352%$6!,5%2%3)$% %6%,/0).'!'2%!4%25.$%234!.$).'/&4(%3#)%.#%/&4(%2#4)# 3%#6)%,,,!/40)/)..'!!.$'2*%!443%422%5!.-$%#2!3.4!4.($%)2.%'&//2&%4(!%333)3#4)%).#3%52/!&.4#(%%2#4)# 5.3$#%),2,7!42))/4%.23!.).$5*%.4$3%4223%4!-.$#).!'.24%('%)2/%.&/!2,%7!%3!34()3%42).03!5442%!2..#3%! .$ 45(.%$)2%3275"2)34%%2135)%..54.)-$%02!3#44!/..$).).'352%2%'$)/.%8!0,/73%5!24%(3%2 0!44%2.3!.$ 4(%)235"3%15%.4)-0!#4/.).352%$%80/352%3 Global Climate Influencer | Arctic Oscillation 1 2 1 Global Climate Influencer | Arctic Oscillation 1 1 Arctic Oscillation Effects on North America and Europe (%2#4)#)3(/-%4/!3%-)0%2-!.%.4,/702%3352%#)2#5,!4)/. +During./7. the!3 positive4(%0/, !phase26/24, %a8 strong(!46/24%8)3).#/.34!.4/00/3)4)/.4/!.$ polar vortex will confine cold air 4(%2%&/2%2%02%3%.43/00/3).'02%3352%4/4(%7%!4(%20!44%2.3/&4(%across Polar Regions. Arctic air is kept in the north, resulting in colder .winters/24(%2. -)$$,%,!4)45$%3)for Canada, Greenland,%./24(%2. northern/24(-%2)#!52/0%!.$3)! Scandinavia and Russia, but keeping the mainland US and most of Europe relatively warm. (%2#4)#3#),,!4)/.-%!352%34(%6!2)!4)/.).4(% 3Resultan42%.'4(tly,) .extratropical4%.3)49!.$ storms3):%/& are4(% flung*%43 fur42%ther!- north!3)4.% AO80! positive.$3 #creates/.42!# storm43!.$y !weather,4%23)4 3in3 Alaska,(!0%4)3-%!352%$"9 the UK and Scandinavia3%!02%3352%, while the !./-!,)%3%)4(%20/3)4)6%/2.%'!4)6%!.$"9/00/3).'!./-!,)%3.%'!4)6%Southwest US and Mediterranean remain dry. /20/3)4)6%).,!4)45$%3 / / 52).'4(%;.%'!4)6%0(!3%</&3%!,%6%,02%3352%)3()'().4(% 2#4)#7(),%,/73%!,%6%,02%3352%$%6%,/03).4(%./24(%2. -)$$,%,!4)45$%3.4(%/4(%2(!.$$52).';0/3)4)6%0(!3%<()'( 3%!,%6%,02%3352%$%6%,/03).4(%./24(%2.-)$$,%,!4)45$%3 Storms areare pushedpushed further northnorth and and affect affect !.$3%!,%6%,02%3352%)3,/7).4(%2#4)# the UK andand Scandinavia.Scandinavia. 2!-%3!.3%.!#,)-!4/,/')34$%3#2)"%34(53 ! Figure 3. Positive phase of Arctic Oscillation. During the negative phase, the polar vortex is weakened by influxes of "warm air from Siberia . Cold air migrates south with the meandering jet stream. Arctic air masses freeze over North America, Europe and Asia, Whyand Mediterranean is it important? countries experience stormy winters. /70/,!2!)202%3352%4%.$34/+%%0&2%%:).'2#4)#!)2 #/.4!).%$!"/6%4(%2#4)#)2#,%7(),%()'(0/,!2!)202%3352% !,,/73-/2%/&4(!4&2)')$!)24/3%%03/54().4//24(-%2)#! !.$52!3)! Storms migratemigrate furtherfurther (%,/#!4)/.!.$342%.'4(/&4(%2#4)#3%!,%6%,02%3352%!./-!,9 south and affectaffect ).&,5%.#%37%!4(%20!44%2.3).4(%/24(%2.%-)30(%2%7(%2%$%.3% southern EuropeEurope andand 0/05,!4)/.3!.$(%!6),9).352%$6!,5%2%3)$% the Mediterranean.