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.

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Global Climate Influencer | Arctic Oscillation 1 1 1

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Global Climate Influencer | Arctic Oscillation 1 2 1

Global Climate Influencer | Arctic Oscillation 1 1

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Global Climate Influencer | Arctic Oscillation 1 3 1

Global Climate Influencer | Arctic Oscillation 2 2

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!‘Snowmageddon’,.$
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 February2#4)#
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In February 2010, the!

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4(53 negative monthly
value in 60 years of record keeping. That month there were three discrete large !


snowstorms: 25 
 

   

 
 

 

” (February 5-6) and 19.5” (February 9-10) in Baltimore, MD, 

 
 



 
 
 
 
and 20.9” (February 25-26) in New York. Such clustering of severe storms  


 

 
 
 





 
is unprecedented, as extreme as the AO reading itself. 
 

 

 
 




 

 



 

 

 



 
Deadly Cold in Europe, February 2012  


 

  
 
  



 



February 2012 saw Europe locked in the grips of deadly cold air, with more  
  

 

  
  





than 650 deaths attributed to the Arctic outbreak. Millions of people in Italy,  
 "
Bosnia and Romania were stranded due to heavy snowfall and power outages. Why93 stations is it fromimportant? the Czech Hydrometeorological Institute reported all-time low temperature recordings, with one station bottoming out at –49.7/7
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Global Climate Influencer | Arctic Oscillation 3 3

Global Climate Influencer | Arctic Oscillation 1 4 1

Arctic Oscillation Superstorm Sandy, Eastern US, Halloween 2012 (%
2#4)#
)3
(/-%
4/
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England coasts during summer 2012. However, ./24(%2.
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AO negative phase. The storm would have traveled out to open sea had the jet stream been straighter, or had the blocking pattern not existed. In this instance, we can see how a negative AO resulted in nearly $30 billion in insured loss within the United States.

Global Climate Influencer | Arctic Oscillation 4 4

Global Climate Influencer | Arctic Oscillation 1 5 1

Arctic Oscillation Bitter Cold, March 2013 (%
2#4)#
)3
(/-%
4/
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3%-)0%2-!.%.4
,/7
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02%3352%
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4(%
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/&
4(%
from weakly positive to strongly negative. The Arctic Oscillation reached the 6 .lowest/24(%2. monthly
-)$$,%
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) recording% in
. 63/24(%2. years
/24(
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52/0%
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and North America, similar to the events of March 2013.

Global Climate Influencer | Arctic Oscillation 15 6 15

FreezingArctic Oscillation Conditions, January 2014 Freezing Conditions, January 2014 In the first full week of January 2014, the US experienced the coldest air In( the%
 first2#4 )full#
) 3week
(/- of%
January4/
!
3% 2014,-)0% the2- !US.% experienced.4
,/7
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outbreak since 1994. Blasts of Arctic air spilled down from the North Pole, outbreak+./7.
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(!4
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air spilled down from the North Pole, smashing many daily low temperature records across the Northeast, Mid- smashing4(%2%&/2%
2%02%3%.43
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02%3352%
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4(%
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many daily low temperature records across the Northeast, Mid- Atlantic, Southeast and Midwest. Atlantic,./24(%2.
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America, allowing the vortex to travel further south into the United States. This anomaly can send cold travel further south into the United States. This anomaly can send cold Arctic air as far south as Texas. Arctic52).'
4(%
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Why is it important? /7
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-. With/2%
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temperature distribution from Weather Underground show how the jet stream’s temperature!.$
52!3 )distribution!
from Weather Underground show how the jet stream’s track influences the spread of cold weather in the continental United States. track influences the spread of cold weather in the continental United States. Notice(%
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the distinct eastward movement4(%
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1 Global Climate Influencer | Arctic Oscillation 1 7 6 Global Climate Influencer | Arctic Oscillation 6 Global Climate Influencer | Arctic Oscillation 6 6

Arctic Oscillation Summary of Conditions (%
2#4)#
)3
(/-%
4/
!
3%-)0%2-!.%.4
,/7
02%3352%
#)2#5,!4)/.
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4(%
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6/24%8
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).
#/.34!.4
/00/3)4)/.
4/
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Why is it important?

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Global Climate Influencer | Arctic Oscillation 1 8 1

Global Climate Influencer | Arctic Oscillation 7 7

Arctic Oscillation The Future (%
2#4)#
)3
(/-%
4/
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3%-)0%2-!.%.4
,/7
02%3352%
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Global Climate Influencer | Arctic Oscillation 1 11 1

Global Climate Influencer | Arctic Oscillation 10 10

Contacts

To discuss any of the contents or implications of this paper, please contact:

James Rohman Global Catastrophe Management, New York

T: 1 (212) 365 2438 E: [email protected]

Geoff Peach Chief Underwriting Officer, Europe and Middle East Region

T: +44-20-7204-8607 E: [email protected]

Louise Rose Senior Vice President, London

T: +44-20-7204-8624 E: [email protected]

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Global Climate Influencer | Arctic Oscillation 1 1

Global Climate Influencer | Arctic Oscillation 11 11