Response of the Dominant Modes of Atmospheric Circulation in the Northern Hemisphere to a Projected Arctic Sea Ice Loss in 2007
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摘要
This study revisits the Arctic sea ice extent(SIE) for the extended period of 1979-2015 based on satellite measurements and finds that the Arctic SIE experienced three different periods: a moderate sea ice decline period for 1979-1996, an accelerated sea ice decline period from 1997 to 2006, and large interannual variation period after 2007, when Arctic sea ice reached its tipping point reported by Livina and Lenton(2013). To address the response of atmospheric circulation to the lowest sea ice conditions with a large interannual variation, we investigated the dominant modes for large atmospheric circulation responses to the projected 2007 Arctic sea ice loss using an atmospheric general circulation model(ECHAM5). The response was obtained from two 50-yr simulations: one with a repeating seasonal cycle of specified sea ice concentration for the period of 1979-1996 and one with that of sea ice conditions in 2007. The results suggest more occurrences of a negative Arctic Oscillation(AO) response to the 2007 Arctic sea ice conditions, accompanied by an North Atlantic Oscillation(NAO)-type atmospheric circulation response under the largest sea ice loss, and more occurrences of the positive Arctic Dipole(AD) mode under the 2007 sea ice conditions, with an across-Arctic wave train pattern response to the largest sea ice loss in the Arctic. This study offers a new perspective for addressing the response of atmospheric circulation to sea ice changes after the Arctic reached the tipping point in 2007.
This study revisits the Arctic sea ice extent(SIE) for the extended period of 1979-2015 based on satellite measurements and finds that the Arctic SIE experienced three different periods: a moderate sea ice decline period for 1979-1996, an accelerated sea ice decline period from 1997 to 2006, and large interannual variation period after 2007, when Arctic sea ice reached its tipping point reported by Livina and Lenton(2013). To address the response of atmospheric circulation to the lowest sea ice conditions with a large interannual variation, we investigated the dominant modes for large atmospheric circulation responses to the projected 2007 Arctic sea ice loss using an atmospheric general circulation model(ECHAM5). The response was obtained from two 50-yr simulations: one with a repeating seasonal cycle of specified sea ice concentration for the period of 1979-1996 and one with that of sea ice conditions in 2007. The results suggest more occurrences of a negative Arctic Oscillation(AO) response to the 2007 Arctic sea ice conditions, accompanied by an North Atlantic Oscillation(NAO)-type atmospheric circulation response under the largest sea ice loss, and more occurrences of the positive Arctic Dipole(AD) mode under the 2007 sea ice conditions, with an across-Arctic wave train pattern response to the largest sea ice loss in the Arctic. This study offers a new perspective for addressing the response of atmospheric circulation to sea ice changes after the Arctic reached the tipping point in 2007.
This study revisits the Arctic sea ice extent(SIE) for the extended period of 1979-2015 based on satellite measurements and finds that the Arctic SIE experienced three different periods: a moderate sea ice decline period for 1979-1996, an accelerated sea ice decline period from 1997 to 2006, and large interannual variation period after 2007, when Arctic sea ice reached its tipping point reported by Livina and Lenton(2013). To address the response of atmospheric circulation to the lowest sea ice conditions with a large interannual variation, we investigated the dominant modes for large atmospheric circulation responses to the projected 2007 Arctic sea ice loss using an atmospheric general circulation model(ECHAM5). The response was obtained from two 50-yr simulations: one with a repeating seasonal cycle of specified sea ice concentration for the period of 1979-1996 and one with that of sea ice conditions in 2007. The results suggest more occurrences of a negative Arctic Oscillation(AO) response to the 2007 Arctic sea ice conditions, accompanied by an North Atlantic Oscillation(NAO)-type atmospheric circulation response under the largest sea ice loss, and more occurrences of the positive Arctic Dipole(AD) mode under the 2007 sea ice conditions, with an across-Arctic wave train pattern response to the largest sea ice loss in the Arctic. This study offers a new perspective for addressing the response of atmospheric circulation to sea ice changes after the Arctic reached the tipping point in 2007.
引文
Alenander,M.A.,Bhatt,U.S.,Wlash,J.E.,Timlin,M.S.,Miller,J.S.,and Scott,J.D.,2004.The atmosphere response to realistic Arctic sea ice anomalies in an AGCM during winter.Journal of Climate,17:890-905.
Barnes,E.A.,2013.Revisiting the evidence linking Arctic amplification to extreme weather in midlatitudes.Geophysical Research Letters,40:4734-4739.
Bhatt,U.S.,Alexander,M.A.,Deser,C.,Walsh,J.E.,Miller,J.S.,Timlin,M.,Scott,J.D.,and Tomas,R.,2008.The atmospheric response to realistic reduced summer Arctic sea ice anomalies.In:Arctic Sea Ice Decline:Observations,Projections,Mechanisms,and Implications.AGU,Washington,D.C.,91-110.
Cohen,J.L.,Furtado,J.C.,Barlow,M.A.,Alexeev,V.A.,and Cherry,J.E.,2012.Arctic warming,increasing snow cover and widespread boreal winter cooling.Environmental Research Letters,7(1):014007.
Cohen,J.L.,Screen,J.A.,Furtado,J.C.,Barlow,M.,Whittleston,D.,Coumou,D.,Francis,J.,Dethloff,K.,Entekhabi,D.,Overland,J.,and Jones,J.,2014.Recent Arctic amplification and extreme mid-latitude weather.Nature Geoscience,7:627-637.
Comiso,J.C.,and Nishio,F.,2008.Trends in the sea ice cover using enhanced and compatible AMSR-E,SSM/I,and SMMRdata.Journal of Geophysical Research:Oceans,113:C02S07.
Comsio,J.C.,Parkinson,C.L.,Gersten,R.,and Stock,L.,2008.Accelerated decline in the Arctic sea ice cover.Geophysical Research Letters,35:L01703.
Dee,D.P.,Uppala,S.M.,Simmons,A.J.,Berrisford,P.,Poli,P.,Kobayashi,S.,Andrae,U.,Balmaseda,M.A.,Balsamo,G.,Bauer,P.,Bechtold,P.,Beljaars,A.C.M.,van de Berg,L.,Bidlot,J.,Bormann,N.,Delsol,C.,Dragani,R.,Fuentes,M.,Geer,A.J.,Haimberger,L.,Healy,S.B.,Hersbach,H.,Hólm,E.V.,Isaksen,L.,K?llberg,P.,K?hler,M.,Matricardi,M.,McNally,A.P.,Monge-Sanz,B.M.,Morcrette,J.J.,Park,B.K.,Peubey,C.,de Rosnay,P.,Tavolato,C.,Thépaut,J.N.,and Vitart,F.,2011.The ERA-Interim reanalysis:Configuration and performance of the data assimilation system.Quarterly Journal of the Royal Meteorological Society,137:553-597.
Deser,C.,and Teng,H.,2008.Evolution of Arctic sea ice concentration trends and the role of atmospheric circulation forcing,1979-2007.Geophysical Research Letters,35:L02504.
Deser,C.,Magnusdottir,G.,Saravanan,R.,and Phillips,A.,2004.The effects of North Atlantic SST and sea ice anomalies on the winter circulation in CCM3.Part II:Direct and indirect components of the response.Journal of Climate,17:877-889.
Deser,C.,Tomas,R.,Alexander,M.,and Lawrence,D.,2010.The seasonal atmospheric response to projected Arctic sea ice loss in the late Twenty-first century.Journal of Climate,23:333-351.
Gerdes,R.,2006.Atmospheric response to changes in Arctic sea ice thickness.Geophysical Research Letters,33:L18709.
Honda,M.,Inoue,J.,and Yamane,S.,2009.Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters.Geophysical Research Letters,36:L08707.
Kurtz,N.,Markus,T.,Farrell,S.,Worthern,D.,and Boisvert,L.,2011.Observations of recent Arctic sea ice volume loss and its impact on ocean-atmosphere energy exchange and ice production.Journal of Geophysical Research:Oceans,116:C04015.
Kwok,R.,Spreen,G.,and Pang,S.,2013.Arctic sea ice circulation and drift speed:Decadal trends and ocean currents.Journal of Geophysical Research:Oceans,118:2408-2425.
Kim,B.,Son,S.W.,Min,S.K.,Jeong,J.H.,Kim,S.J.,Zhang,X.,Shim,T.,and Yoon,J.H.,2014.Weakening of the stratospheric polar vortex by Arctic sea-ice loss.Nature Communications,5:4646,DOI:10.1038/ncomms5646.
L’Heureux,M.L.,Kumar,A.,Bell,G.D.,Halpert,M.S.,and Higgins,R.W.,2008.Role of the Pacific-North American(PNA)pattern in the 2007 Arctic sea ice decline.Geophysical Research Letters,35:L20701.
Livina,V.N.,and Lenton,T.M.,2013.A recent tipping point in the Arctic sea-ice cover:Abrupt and persistent increase in the seasonal cycle since 2007.The Cryosphere,7:275-286.
Liu,J.,Curry,J.,Wang,H.,Song,M.,and Horton,R.,2012.Impact of declining Arctic sea ice on winter snowfall.Proceedings of the National Academy of Sciences,109:4074-4079.
Nakamura,T.,Yamazaki,K.,Iwamoto,K.,Honda,M.,Miyoshi,Y.,Ogawa,Y.,and Ukita,J.,2015.A negative phase shift of the winter AO/NAO due to the recent Arctic sea-ice reduction in late autumn.Journal of Geophysical Research:Atmospheres,120:3209-3227.
Maslanik,J.,Drobot,S.,Fowler,C.,Emery,W.,and Barry,R.,2007.On the Arctic climate paradox and the continuing role of atmospheric circulation in affecting sea ice conditions.Geophysical Research Letters,34:L03711.
Mori,M.,Watanabe,M.,Shigeo,H.,Inoue,J.,and Kimoto,M.,2014.Robust Arctic sea-ice influence on the frequent Eurasian cold winters in past decades.Nature Geoscience,7:869-873.
Ogi,M.,and Rigor,I.G.,2013.Trends in Arctic sea ice and the role of atmospheric circulation.Atmospheric Science Letters,14:97-101.
Ogi,M.,and Yamazaki,K.,2010.Trends in the summer Northern Annual Mode and Arctic sea ice.Scientific Online Letters on Atmosphere,6:41-44.
Ogi,M.,Rigor,I.G.,McPhee,M.G.,and Wallace,J.M.,2008.Summer retreat of Arctic sea ice:Role of summer winds.Geophysical Research Letters,35:L24701.
Overland,J.E.,and Wang,M.,2010.Large-scale atmospheric circulation changes are associated with the recent loss of Arctic sea ice.Tellus A,62:1-9.
Overland,J.E.,Francis,J.,Hall,R.,Hanna,E.,Kim,S.,and Vihma,T.,2015.The melting Arctic and midlatitude weather patterns:Are they connected?Journal of Climate,28:7917-7932.
Overland,J.E.,Wang,M.,and Salo,S.,2008.The recent Arctic warm period.Tellus,60:589-597.
Peings,Y.,and Magunsdottir,G.,2013.Response of the wintertime northern hemisphere atmospheric circulation to current and projected Arctic sea ice decline:A numerical study with CAM5.Journal of Climate,27:244-263.
Reyner,N.A.,Parker,D.E.,Horton,E.B.,Folland,C.K.,Alexander,L.V.,Rowell,D.P.,Kent,E.C.,and Kaplan,A.,2003.Global analysis of sea surface temperature,sea ice,and night marine air temperature since the late nineteenth century.Journal of Geophysical Research:Atmospheres,108:4407.
Rigor,I.G.,Wallace,J.M.,and Colony,R.L.,2002.Response of sea ice to the Arctic Oscillation.Journal of Climate,15:2648-2663.
Rudels,B.,and Quadfasel,D.,1991.Convection and deep water formation in the Arctic Ocean-Greenland Sea system.Journal of Marine Systems,2:435-450.
Screen,J.,2013.Influence of Arctic sea ice on European summer precipitation.Environmental Research Letters,8:044015.
Screen,J.A.,and Simmonds,I.,2010.The central role of diminishing sea ice in recent Arctic temperature amplification.Nature,464:1334-1337.
Screen,J.,Simmonds,I.,Deser,C.,and Tomas,R.,2012.The atmospheric response to three decades of observed Arctic sea ice loss.Journal of Climate,26:1230-1248.
Screen,J.A.,Simmonds,I.,Deser,C.,and Tomas,R.,2013.The atmospheric response to three decades of observed Arctic sea ice loss.Journal of Climate,26:1230-1248.
Seierstad,I.A.,and Bader,J.,2009.Impact of a projected future Arctic sea ice reduction on extratropical storminess and the NAO.Climate Dynamics,33:937-943.
Serreze,M.C.,and Barry,R.G.,2011.Processes and impacts of Arctic amplification:A research synthesis.Global and Planetary Change,77:85-96.
Serreze,M.C.,Holland,M.M.,and Stroeve,J.,2007.Perspectives on the Arctic’s shrinking sea-ice cover.Science,315:1533-1536.
Sewall,J.O.,2005.Precipitation shifts over western North America as a result of declining Arctic sea ice cover,the coupled system response.Earth Interactions,9(26):1.
Singarayer,J.S.,Bamber,J.L.,and Valdes,P.J.,2006.Twentyfirst-century climate impacts from a declining Arctic sea ice cover.Journal of Climate,19:1109-1125.
Sun,L.,Deser,C.,and Tomas,R.,2015.Mechanisms of stratospheric and tropospheric circulation response to projected Arctic sea ice loss.Journal of Climate,28:7824-7845.
Thompson,D.W.,and Wallace,J.M.,1998.The Arctic Oscillation signature in the wintertime geopotential height and temperature fields.Geophysical Research Letters,25:1297-1300.
Walsh,J.E.,2014.Intensified warming of the Arctic:Causes and impacts on middle latitudes.Global Planet Change,117:52-63.
Wang,J.,and Ikeda,M.,2000.Arctic Oscillation and Arctic sea ice oscillation.Geophysical Research Letters,17:1287-1290.
Wang,J.,Zhang,J.,Watanabe,E.,Ikeda,M.,Mizobata,K.,Walsh,J.E.,Bai,X.,and Wu,B.,2009.Is the dipole anomaly a major driver to record lows in Arctic summer sea ice extent?Geophysical Research Letters,36:L05706.
Watanabe,E.,Wang,J.,Sumi,A.,and Hasumi,H.,2006.Arctic dipole anomaly and its contribution to sea ice export from the Arctic Ocean in the 20th century.Geophysical Research Letters,33:L23703.
Wu,B.,Wang,J.,and Walsh,J.E.,2006.Dipole anomaly in the winter Arctic atmosphere and its association with Arctic sea ice motion.Journal of Climate,19:210-225.
Barnes,E.A.,2013.Revisiting the evidence linking Arctic amplification to extreme weather in midlatitudes.Geophysical Research Letters,40:4734-4739.
Bhatt,U.S.,Alexander,M.A.,Deser,C.,Walsh,J.E.,Miller,J.S.,Timlin,M.,Scott,J.D.,and Tomas,R.,2008.The atmospheric response to realistic reduced summer Arctic sea ice anomalies.In:Arctic Sea Ice Decline:Observations,Projections,Mechanisms,and Implications.AGU,Washington,D.C.,91-110.
Cohen,J.L.,Furtado,J.C.,Barlow,M.A.,Alexeev,V.A.,and Cherry,J.E.,2012.Arctic warming,increasing snow cover and widespread boreal winter cooling.Environmental Research Letters,7(1):014007.
Cohen,J.L.,Screen,J.A.,Furtado,J.C.,Barlow,M.,Whittleston,D.,Coumou,D.,Francis,J.,Dethloff,K.,Entekhabi,D.,Overland,J.,and Jones,J.,2014.Recent Arctic amplification and extreme mid-latitude weather.Nature Geoscience,7:627-637.
Comiso,J.C.,and Nishio,F.,2008.Trends in the sea ice cover using enhanced and compatible AMSR-E,SSM/I,and SMMRdata.Journal of Geophysical Research:Oceans,113:C02S07.
Comsio,J.C.,Parkinson,C.L.,Gersten,R.,and Stock,L.,2008.Accelerated decline in the Arctic sea ice cover.Geophysical Research Letters,35:L01703.
Dee,D.P.,Uppala,S.M.,Simmons,A.J.,Berrisford,P.,Poli,P.,Kobayashi,S.,Andrae,U.,Balmaseda,M.A.,Balsamo,G.,Bauer,P.,Bechtold,P.,Beljaars,A.C.M.,van de Berg,L.,Bidlot,J.,Bormann,N.,Delsol,C.,Dragani,R.,Fuentes,M.,Geer,A.J.,Haimberger,L.,Healy,S.B.,Hersbach,H.,Hólm,E.V.,Isaksen,L.,K?llberg,P.,K?hler,M.,Matricardi,M.,McNally,A.P.,Monge-Sanz,B.M.,Morcrette,J.J.,Park,B.K.,Peubey,C.,de Rosnay,P.,Tavolato,C.,Thépaut,J.N.,and Vitart,F.,2011.The ERA-Interim reanalysis:Configuration and performance of the data assimilation system.Quarterly Journal of the Royal Meteorological Society,137:553-597.
Deser,C.,and Teng,H.,2008.Evolution of Arctic sea ice concentration trends and the role of atmospheric circulation forcing,1979-2007.Geophysical Research Letters,35:L02504.
Deser,C.,Magnusdottir,G.,Saravanan,R.,and Phillips,A.,2004.The effects of North Atlantic SST and sea ice anomalies on the winter circulation in CCM3.Part II:Direct and indirect components of the response.Journal of Climate,17:877-889.
Deser,C.,Tomas,R.,Alexander,M.,and Lawrence,D.,2010.The seasonal atmospheric response to projected Arctic sea ice loss in the late Twenty-first century.Journal of Climate,23:333-351.
Gerdes,R.,2006.Atmospheric response to changes in Arctic sea ice thickness.Geophysical Research Letters,33:L18709.
Honda,M.,Inoue,J.,and Yamane,S.,2009.Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters.Geophysical Research Letters,36:L08707.
Kurtz,N.,Markus,T.,Farrell,S.,Worthern,D.,and Boisvert,L.,2011.Observations of recent Arctic sea ice volume loss and its impact on ocean-atmosphere energy exchange and ice production.Journal of Geophysical Research:Oceans,116:C04015.
Kwok,R.,Spreen,G.,and Pang,S.,2013.Arctic sea ice circulation and drift speed:Decadal trends and ocean currents.Journal of Geophysical Research:Oceans,118:2408-2425.
Kim,B.,Son,S.W.,Min,S.K.,Jeong,J.H.,Kim,S.J.,Zhang,X.,Shim,T.,and Yoon,J.H.,2014.Weakening of the stratospheric polar vortex by Arctic sea-ice loss.Nature Communications,5:4646,DOI:10.1038/ncomms5646.
L’Heureux,M.L.,Kumar,A.,Bell,G.D.,Halpert,M.S.,and Higgins,R.W.,2008.Role of the Pacific-North American(PNA)pattern in the 2007 Arctic sea ice decline.Geophysical Research Letters,35:L20701.
Livina,V.N.,and Lenton,T.M.,2013.A recent tipping point in the Arctic sea-ice cover:Abrupt and persistent increase in the seasonal cycle since 2007.The Cryosphere,7:275-286.
Liu,J.,Curry,J.,Wang,H.,Song,M.,and Horton,R.,2012.Impact of declining Arctic sea ice on winter snowfall.Proceedings of the National Academy of Sciences,109:4074-4079.
Nakamura,T.,Yamazaki,K.,Iwamoto,K.,Honda,M.,Miyoshi,Y.,Ogawa,Y.,and Ukita,J.,2015.A negative phase shift of the winter AO/NAO due to the recent Arctic sea-ice reduction in late autumn.Journal of Geophysical Research:Atmospheres,120:3209-3227.
Maslanik,J.,Drobot,S.,Fowler,C.,Emery,W.,and Barry,R.,2007.On the Arctic climate paradox and the continuing role of atmospheric circulation in affecting sea ice conditions.Geophysical Research Letters,34:L03711.
Mori,M.,Watanabe,M.,Shigeo,H.,Inoue,J.,and Kimoto,M.,2014.Robust Arctic sea-ice influence on the frequent Eurasian cold winters in past decades.Nature Geoscience,7:869-873.
Ogi,M.,and Rigor,I.G.,2013.Trends in Arctic sea ice and the role of atmospheric circulation.Atmospheric Science Letters,14:97-101.
Ogi,M.,and Yamazaki,K.,2010.Trends in the summer Northern Annual Mode and Arctic sea ice.Scientific Online Letters on Atmosphere,6:41-44.
Ogi,M.,Rigor,I.G.,McPhee,M.G.,and Wallace,J.M.,2008.Summer retreat of Arctic sea ice:Role of summer winds.Geophysical Research Letters,35:L24701.
Overland,J.E.,and Wang,M.,2010.Large-scale atmospheric circulation changes are associated with the recent loss of Arctic sea ice.Tellus A,62:1-9.
Overland,J.E.,Francis,J.,Hall,R.,Hanna,E.,Kim,S.,and Vihma,T.,2015.The melting Arctic and midlatitude weather patterns:Are they connected?Journal of Climate,28:7917-7932.
Overland,J.E.,Wang,M.,and Salo,S.,2008.The recent Arctic warm period.Tellus,60:589-597.
Peings,Y.,and Magunsdottir,G.,2013.Response of the wintertime northern hemisphere atmospheric circulation to current and projected Arctic sea ice decline:A numerical study with CAM5.Journal of Climate,27:244-263.
Reyner,N.A.,Parker,D.E.,Horton,E.B.,Folland,C.K.,Alexander,L.V.,Rowell,D.P.,Kent,E.C.,and Kaplan,A.,2003.Global analysis of sea surface temperature,sea ice,and night marine air temperature since the late nineteenth century.Journal of Geophysical Research:Atmospheres,108:4407.
Rigor,I.G.,Wallace,J.M.,and Colony,R.L.,2002.Response of sea ice to the Arctic Oscillation.Journal of Climate,15:2648-2663.
Rudels,B.,and Quadfasel,D.,1991.Convection and deep water formation in the Arctic Ocean-Greenland Sea system.Journal of Marine Systems,2:435-450.
Screen,J.,2013.Influence of Arctic sea ice on European summer precipitation.Environmental Research Letters,8:044015.
Screen,J.A.,and Simmonds,I.,2010.The central role of diminishing sea ice in recent Arctic temperature amplification.Nature,464:1334-1337.
Screen,J.,Simmonds,I.,Deser,C.,and Tomas,R.,2012.The atmospheric response to three decades of observed Arctic sea ice loss.Journal of Climate,26:1230-1248.
Screen,J.A.,Simmonds,I.,Deser,C.,and Tomas,R.,2013.The atmospheric response to three decades of observed Arctic sea ice loss.Journal of Climate,26:1230-1248.
Seierstad,I.A.,and Bader,J.,2009.Impact of a projected future Arctic sea ice reduction on extratropical storminess and the NAO.Climate Dynamics,33:937-943.
Serreze,M.C.,and Barry,R.G.,2011.Processes and impacts of Arctic amplification:A research synthesis.Global and Planetary Change,77:85-96.
Serreze,M.C.,Holland,M.M.,and Stroeve,J.,2007.Perspectives on the Arctic’s shrinking sea-ice cover.Science,315:1533-1536.
Sewall,J.O.,2005.Precipitation shifts over western North America as a result of declining Arctic sea ice cover,the coupled system response.Earth Interactions,9(26):1.
Singarayer,J.S.,Bamber,J.L.,and Valdes,P.J.,2006.Twentyfirst-century climate impacts from a declining Arctic sea ice cover.Journal of Climate,19:1109-1125.
Sun,L.,Deser,C.,and Tomas,R.,2015.Mechanisms of stratospheric and tropospheric circulation response to projected Arctic sea ice loss.Journal of Climate,28:7824-7845.
Thompson,D.W.,and Wallace,J.M.,1998.The Arctic Oscillation signature in the wintertime geopotential height and temperature fields.Geophysical Research Letters,25:1297-1300.
Walsh,J.E.,2014.Intensified warming of the Arctic:Causes and impacts on middle latitudes.Global Planet Change,117:52-63.
Wang,J.,and Ikeda,M.,2000.Arctic Oscillation and Arctic sea ice oscillation.Geophysical Research Letters,17:1287-1290.
Wang,J.,Zhang,J.,Watanabe,E.,Ikeda,M.,Mizobata,K.,Walsh,J.E.,Bai,X.,and Wu,B.,2009.Is the dipole anomaly a major driver to record lows in Arctic summer sea ice extent?Geophysical Research Letters,36:L05706.
Watanabe,E.,Wang,J.,Sumi,A.,and Hasumi,H.,2006.Arctic dipole anomaly and its contribution to sea ice export from the Arctic Ocean in the 20th century.Geophysical Research Letters,33:L23703.
Wu,B.,Wang,J.,and Walsh,J.E.,2006.Dipole anomaly in the winter Arctic atmosphere and its association with Arctic sea ice motion.Journal of Climate,19:210-225.