Recent Arctic ozone depletion: Is there an impact of climate change?

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Recent Arctic ozone depletion: Is there an impact of

climate change?

Jean-Pierre Pommereau, Florence Goutail, Andrea Pazmino, Franck Lefèvre,

Martyn P. Chipperfield, Wuhu Feng, Michel van Roozendaël, Nis Jepsen,

Georg Hansen, Rigel Kivi, et al.

To cite this version:

Jean-Pierre Pommereau, Florence Goutail, Andrea Pazmino, Franck Lefèvre, Martyn P. Chipperfield,

et al.. Recent Arctic ozone depletion: Is there an impact of climate change?. Comptes Rendus

Géoscience, Elsevier Masson, 2018, 350 (7), pp.347-353. �10.1016/j.crte.2018.07.009�. �insu-01898091�

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External

Geophysics,

Climate

(Aeronomy

and

Meteorology)

Recent

Arctic

ozone

depletion:

Is

there

an

impact

of

climate

change?

Jean-Pierre

Pommereau

a,

*

,

Florence

Goutail

a

,

Andrea

Pazmino

a

,

Franck

Lefe`vre

a

,

Martyn

P. Chipperﬁeld

b

,

Wuhu

Feng

b

,

Michel

Van

Roozendael

c

,

Nis

Jepsen

d

,

Georg

Hansen

e

,

Rigel

Kivi

f

,

Kristof

Bognar

g

,

Kimberley

Strong

g

,

Kaley

Walker

g

,

Alexandr

Kuzmichev

h

,

Slava

Khattatov

h

,

Vera

Sitnikova

h

a_LATMOS,_CNRS,_UVSQ,_Guyancourt,_France b

NationalCentreforAtmosphericScience,SchoolofEarthandEnvironment,UniversityofLeeds,Leeds,UK

c

BelgianInstituteforSpaceAeronomy(BIRA),Brussels,Belgium

d

DanishMeteorologicalInstitute,Copenhagen,Denmark

e

NorwegianInstituteforAirResearch,Kjeller,Norway

f

FinnishMeteorologicalInstitute,Sodankyla¨,Finland

g_Department_of_Physics,_University_of_Toronto,_Toronto,_Canada h_Central_Aerological_Observatory,_Dolgoprudny,_Moscow,_Russia

ARTICLE INFO Articlehistory:

Received8February2018 Acceptedafterrevision6July2018 Availableonline16October2018 HandledbyIrinaPetravloskikh Keywords:

Recentstratosphericozonedepletion Arctic

Impactonclimatechange

ABSTRACT

Afterthewell-reportedrecordlossofArcticstratosphericozoneofupto38%inthewinter 2010–2011,furtherlargedepletionof27%occurredinthewinter2015–2016.Recordlow winterpolarvortextemperatures,belowthethresholdforicepolarstratosphericcloud (PSC)formation,persistedforonemonthinJanuary2016.Thisisthefirstobservationof suchaneventandresultedinunprecedenteddehydration/denitrificationofthepolar vortex.Althoughchemistry–climatemodels(CCMs)generallypredictfurthercoolingof thelowerstratospherewiththeincreasingatmosphericconcentrationsofgreenhouse gases(GHGs),significantdifferencesarefoundbetweenmodelresultsindicatingrelatively largeuncertaintiesinthepredictions.Thelinkbetweenstratospherictemperatureand ozonelossiswellunderstoodandtheobservedrelationshipiswellcapturedbychemical transportmodels(CTMs).However,thestrongdynamicalvariabilityintheArcticmeans thatlargeozonedepletioneventslikethoseof2010–2011and2015–2016maystilloccur untiltheconcentrationsofozone-depletingsubstancesreturntotheir1960values.Itis thuslikelythatthestratosphericozonerecovery,currentlyanticipatedforthemid-2030s, mightbesignificantlydelayed.Mostimportantinordertopredictthefutureevolutionof Arcticozoneandtoreducetheuncertaintyofthetimingforitsrecoveryistoensure continuationofhigh-qualityground-basedandsatelliteozoneobservationswithspecial focusonmonitoringtheannualozonelossduringtheArcticwinter.

C 2018Acade´miedessciences.PublishedbyElsevierMassonSAS.Thisisanopenaccess

articleundertheCCBY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

* Correspondingauthor.

E-mailaddress:Jean-Pierre.Pommereau@latmos.ipsl.fr(J.-P.Pommereau).

ContentslistsavailableatScienceDirect

Comptes

Rendus

Geoscience

w ww . sc i e nce d i re ct . co m

https://doi.org/10.1016/j.crte.2018.07.009

1631-0713/ C ₂₀₁₈_Acade´mie_des_sciences._Published_by_Elsevier_Masson_SAS._This_is_an_open_access_article_under_the_CC_BY-NC-ND_license₍_http://

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1. Introduction

A record 38% ozone depletion of about 160 DU,

comparableinmagnitudetothatoftheAntarctic,occurred intheArcticwinter2011(Adamsetal.,2012;Arnoneetal.,

2012;Grifﬁnetal.,2018;Lindenmaieretal.,2012;Manney

et al., 2011; Pommereau et al., 2013; Sinnhuber et al.,

2011).Itwasattributedtoanunusuallypersistentpolar vortexthatlasteduntiltheendofMarch.Morerecently,a 27% (120DU) depletion, thethird largest inmagnitude

since the beginning of SAOZ (‘‘Syste`me d’Analyse par

Observation Ze´nithale’’, Pommereau and Goutail, 1988) ozonecolumnobservationsin1990,occurredinthewinter 2015–2016.In thatyear,thestrongestandcoldestpolar vortexofthelast68yearswasobservedduringaperiodof reduced@planetarywave(PW)amplitude(Matthiasetal.,

2016;Rexetal.,2016).AsshownbytheAuraMicrowave

Limb Sounder (MLS), such record low temperatures

resultedinexceptionalvortex-widedehydrationbetween

the 410 K and 520 K potential temperature levels,

somethingnever observed before in the Arctic. The

observeddenitriﬁcationwasalsoexceptional,and exten-sivechlorine activation and chemical ozone loss began earlierthanintherecenthighlosswinters.However,the magnitudeofchemicalozonedepletionwaslimitedbyan earlymajorﬁnalwarmingatthestartofMarch(Manney

andLawrence,2016).

Thequestionis thereforetounderstandwhether the

frequency of the anomalously cold and strong vortex

conditionswillincreaseinthefutureandthuspersistently createconditionsforlargechemicalozoneloss.Thefuture

frequency of these episodes will be inﬂuenced by the

continuouscoolingofthestratospherethroughincreasing concentrationsofgreenhousegases(GHGs),aspredictedin

chemistry–climate models (CCMs). These processes can

delay the Arcticozone recovery currently predicted by

CCMs for the mid-2030s (Dhomse et al., 2018; WMO,

2014).Using theECHAM/MESSyAtmospheric Chemistry

(EMAC)CCM,Langematzetal.(2014)suggestedthatthe futureArcticstratospherewouldcoolsigniﬁcantlyinearly

winter. Using the Met Ofﬁce Uniﬁed Model–United

KingdomChemistryandAerosol(UMUKCA)CCM,Bednarz

et al. (2016) conﬁrmed to some extent the predicted

coolingof themiddle and upper stratosphere,but also underlinedthelowconﬁdenceintheprojected tempera-ture trends in the lower stratosphere. In addition, like

Langematz et al. (2014), they conﬁrmed the possible

occurrence of signiﬁcant episodic large ozone column

reductions because of the large interannual dynamical

variabilityoftheArcticatmosphere.

Theobjective of this paper is toinvestigate whether thereareindicationsthatArcticozonerecovery,currently

predicted for 2030–2040 (Dhomse et al., 2018; WMO,

2014), might be delayed and whether large episodic

depletionsmight stilloccur followingthe coolingof the

lower stratosphere predicted by the climate models.

Section 2 provides an update of recent ozone loss and

denoxiﬁcationevents observed by the SAOZ networkin

2015–2016 and 2016–2017. The temperatures recorded

in the Arctic vortex duringthese yearsare describedin Section 3. The possible impact of the further predicted

coolingofthestratosphereonozoneisthendiscussedin Section4,andourconclusionsaresummarizedinSection5.

2. Ozonelossin2015–2016and2016–2017

TheozonelossisderivedfromSAOZcolumn observa-tions at eight stations in the Arctic (Table 1), where measurementsareperformedtwicedailyatsolarzenith angles(SZAs)between86and918.Thusourobservations extenduptothepolarcircleatthewintersolstice.Table1 showsthelatitudeandyearoftheﬁrstobservationsateach station.

Theozonelossandthe amplitudeofthe NO2diurnal variationreportedduringthe wintersof2015–2016 and 2016–2017 are shownin Fig. 1. Theozone lossat each stationiscalculatedbyapassivemethodwheremeasured

columns are compared to those provided by chemical

transport models (CTMs) that ignore chemistry, as

de-scribedbyGoutailetal.(1999).Grifﬁnetal.(2018)recently showedthatthismethodprovidessmalleruncertaintiesin

ozone loss calculations than other approaches. Also

displayed in Fig.1 is the nitrogendioxide(NO2)diurnal variation,anindicatorofchlorineactivation.Indeed,since NOxistransformedintoClONO2inthepresenceofactivated

chlorine, the absence of NO2 during night time is an

indicatorofchlorineactivation(Pommereauetal.,2013). During the winter 2015–2016, the afternoon NO2 levels remainedlowuntiltheendofFebruary,whenthechlorine activationstoppedandtheozonecolumndepletionreached atotalof273%onMarch20,atameanrateof0.5%/day.In contrast in the winter 2016–2017, the chlorine-activated periodwasshorterandendedinlateJanuary,thelossratewas smallerat0.2%/day,andthetotalozonedepletionamplitude reachedonly163%.

The long-term history of the ozone loss since the

beginningofSAOZnetworkmeasurementsin1990andthe resultsoftheCTMsREPROBUS(Lefevreetal.,1994)and SLIMCAT(Chipperﬁeld,1999)areshowninFig.2.Although stoppedbythemajorstratosphericﬁnalwarminginearly March,the2015–2016ozonedepletionisthethirdlargest afterthepeakof1995–1996andtherecordlossof2010– 2011.Remarkably,casesofsmallozonedepletion,which

were frequent between 1998 and 2005 due to early

warmingsinlateDecemberorearlyJanuary,arenolonger

observed after 2005. As shown by the EMAC model

simulations, this is consistent with the early winter

coolingofthestratospherebelowthethreshold tempera-tureofnitricacidtrihydrate(NAT)PSCformation(TNAT) observedeverywinterafter2005,resultinginaminimum ozonedepletionofatleast12–15%eachyear.

Table1

SAOZArcticstations,latitude,longitudeandyearofﬁrstobservations.

Eureka,Nunavut 808N,868W 2006 Ny-Alesund,Svalbard 788N,128E 1991 Thule,Greenland 768N,698W 1991 Scoresbysund,Greenland 718N,228W 1991 Sodankyla,Finland 678N,278E 1990 Salekhard,Russia 678N,678E 1998 Zhigansk,Russia 678N,1238E 1992 Harestua,Norway 608N,118E 1994

J.-P.Pommereauetal./C.R.Geoscience350(2018)347–353 348

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RegardingtheCTMsimulationswithinteractive chem-istry, thedepletionamplitudes of 273% in2015–2016 and163%in2016–2017arewellcapturedbythemodels with,respectively,24.31.9%and132%inREPROBUS,and 252%and112%inSLIMCAT.Anexceptiontothegood agreement over the recentSAOZ record isin 2012–2013, whenbothmodelssigniﬁcantlyunderestimatetheobserved ozoneloss.

Fig.3showstherelationshipbetweenSAOZozoneloss amplitudeandNATpolarPSCilluminated(sunlit)volume.

The NAT PSC sunlit volume is calculated in the lower

stratospherebetween 400and 675Kpotential

tempera-turesurfaces (Pommereau etal., 2013). The2015–2016

and 2016–2017 episodes are fully consistent with the

otherwinters,conﬁrmingthelinearrelationshipbetween

ozone loss and NAT PSC sunlit volume, indicative of

chlorineactivation(Chipperﬁeldetal.,2005;Pommereau

etal.,2013;Rexetal.,2004).

3. StratospherictemperaturesinthewinterArctic

Fig. 4 shows the minimum ECMWF ERA-Interim

temperaturesatthe475Kisentropiclevel(approximately

18km),reported eachwintersince1990northof608N. Thebold blueline is forwinter1996,when thesecond largestozonelosssofarobservedoccurred.Theboldblack lineisfortherecordlossof2010–2011,theredlinefor

2015–2016, and the green line for the relatively warm

2016–2017winter.Also shownareTNATandtheicePSC formationtemperature(TICE).

Asalreadynoted, theearlystratospheric warmingin

December and January observed frequently before

2005didnot occurafter2005,whichisconsistentwith themodelstudyofLangematzetal.(2014).The tempera-tureisoftenbelowTNATforseveralweeks.However,apart

from short-duration ice PSC episodes associated with

mountain-wave events, like those observed by the

ALOMARlidarinnorthernNorwayinJanuary1996(e.g.,

Hansen and Hoppe, 1997), a long duration period with

T<TICEhappenedrecentlyonly(Fig.4).Theﬁrstsigniﬁcant T<TICE episode, which lasted two weeks after mid-Februaryinthewinter2010–2011,resultedintherecord ozone loss event.A T<TICEevent like themost recent,

whichlasted foronemonth inJanuary2016,hadnever

beenobservedbeforeintheArctic.ThisJanuary2016event resultedinthefastsedimentationoficeparticlesleadingto

Fig.1. Timeseriesofobservedozoneloss(%)insidethevortex(toppanels)andtheamplitudeoftheNO2diurnalvariation(bottompanels),aboveeachSAOZ

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theunprecedenteddehydrationanddenitriﬁcationofthe

stratosphere (Manney and Lawrence, 2016) and the

completedenoxiﬁcationuntillate February,asobserved bySAOZ(Fig.1).

4. Discussion

The winters1995–1996,2010–2011,and 2015–2016

havebeenthecoldestsofarsincethebeginningofSAOZ

Fig.2.Ozonecolumnlossmagnitude(%)reportedbytheSAOZnetworkeachyearsince1990andcalculatedbythetwochemicaltransportmodels REPROBUSandSLIMCAT.

Fig.3.MagnitudeofSAOZozoneloss(%)versusnitricacidtrihydrate(NAT)PSCsunlitvolume(VPSC)betweenthe400–675Klevels. J.-P.Pommereauetal./C.R.Geoscience350(2018)347–353

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observations, and they resulted in thelargest observed ozonelosses.AlthoughArcticstratosphericozonerecovery

is predicted to occur in the mid 2030s, there is no

indication yet of reduced ozone loss at northern polar latitudes, in contrast to the Antarctic (Solomon et al., 2016).Arcticozonedepletiontypicallyamountsto12–15%

(30–50 DU) each year, reaching 25% (60 DU) during

moderatelycoldwinters,canbeaslargeas38%(160DU)in extremecases.Sincethereisaclearrelationshipbetween stratospheric temperature and ozone loss while strato-sphericchlorineandbromineloadingsremainelevated,if thecoolingofthestratospherecontinues,thereisaserious risk of experiencing further extreme loss events before theconcentrationsofozone-depletingsubstances(ODSs) returntotheirpre-depletionvalues.Thequestionisthusto

understand how the temperature of the Arctic lower

stratospherewillevolveinthefuture.

Using Chemistry–Climate Model Initiative (CCMI)

EMAC simulations, Langematz et al. (2014) concluded

thatthelowerstratosphereminimumtemperature(Tmin)

north of 408 N is decreasing in the early winter

(November–December)atameanrateof 0.180.05K/

decade since 1960, but at a slightly slower rate

( 0.110.05K/decade)inJanuary–February.According to theirpredictions,thecoolingwillcontinueuntil2100.Using

ECMWF ERA-Interim and NASA MERRA meteorological

reanalysis datasets, Bohlinger et al. (2014) also studied long-term stratospherictemperature changes. They found thattheArcticlowerstratosphereat50hPabetween60–908 Nhasbeencooling,fasterthanpredictedbytheEMACmodel, atarateof 0.410.11K/decadeoverthelast32years.Like Langematzetal., Bohlingeretal.also suggestedafurther coolingoftheArcticstratosphereoverthecomingdecades duetoradiativecoolinglargelycontrolledbythechangesin

GHGs,butatslowerrateof 0.150.06K/decadeforEMAC

and 0.100.02K/decade for the Climate Validation

(CCMVal2)project.Finally,fromtheseven-member ensem-blesimulationsoftheUMUKCA,Bednarzetal.(2016)also concludedthattherewouldbeastatisticallysigniﬁcant long-termcoolingthroughoutmostofthepolarstratospherein earlywinter,inagreementwithLangematzetal.(2014).The resultsalsoindicateastrengtheningofthedeepbranchofthe Brewer–Dobsoncirculationinborealwinter(Hardimanetal., 2014),implyinganincreaseindownwellingovertheArctic fromDecembertoFebruaryof0.0150.007mm/s/decade. Regarding ozone,theensemble modelsimulationsleadto theconclusionthat althoughthetotalcolumninMarchis expectedtoincreaseatarateof11.5DU/decadeinthe21st century,thespringtimeArcticozonecanepisodicallydrop by50–100DU,meaningthatindividualyearswith spring-timeozonedepletionassevereasthatof2011willremain possibleinthefuture.Furthermore,Sunetal.(2014),using

the Whole Atmosphere Community Climate Model

(WACCM), have shown that the predicted seaice loss in the Arctic could lead to a decrease of the upward wave

propagation, a strengthening of the polar vortex, an

additionalcoolingofthestratosphere,andthenapolarcap stratosphericozonedecreaseby13DU(34DUattheNorth Pole)inspring.UsingCCMIresults,Morgensternetal.(2017)

examined the degree of consistency in column ozone

predictionsbetweensevenmodelsandfoundconsiderable disagreement,whichtheyattributetointer-model differen-cesinlowerstratospherictransportanddynamical respon-ses.Theyconcludedthatthereisalotofuncertaintyinthe future evolution of temperature. Finally, from the more recent155simulationsperformed by20models inthein theframeofCCMI,Dhomseetal.(2018)concludedthatthe return dates of ozoneto the 1980 level, will be later by

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approximately 5–17years than those presented in the 2014OzoneAssessment.However, likeMorgensternetal., theyalsofoundasigniﬁcantuncertaintyinthepredictions. 5. Conclusions

Inconclusion,allmodelpredictionsagreewithafurther coolingoftheArcticlowerstratosphereduetoincreasing GHGconcentrations. However, signiﬁcant differencesin themodelskillarefound,e.g., predictionofthecooling episodeslimitedtotheearlywinterorextendingthrough thewholewinter,coolinglimitedtothemiddleandupper stratosphere or extending to all levels, related to the strengtheningorweakeningoftheBrewer–Dobson circu-lation, or additional stratospheric cooling after sea ice melting, etc. Generally speaking, model predictions are

consistent with the observed cooling of the lower

stratosphereduringthe winter,consistent, for example,

withthe recent low temperature recordof 2015–2016.

CCMIsimulationsalsoagreewiththerelationshipbetween temperatureandozone loss,forwhich observationsare

well captured by chemical transport models. The high

variability of Arctic meteorology implies that large

chemical ozone depletion events like those of 2010–

2011 and 2015–2016 might still occur until the ODS

concentrations return to their 1960 values. The Arctic stratosphericozonerecoverypredictedforthemid2030s mightbethussigniﬁcantlydelayed.

Mostimportant in ordertopredict thefuture Arctic ozoneevolutionandreducetheuncertaintyofthetiming

for ozone recovery is to ensure continuation of

high-quality ozone observations in the Arcticwith adequate

instruments, UV-Vis ground-based (Pommereau et al.,

2013), radiosondes (Rex et al., 2004), Microwave MLS

(Waters et al.,2006)and IRIASI(Boynardet al.,2018),

performingathighlatitudeinwinter.

Acknowledgments

Theauthorsareindebtedtothepersonneloperatingthe

SAOZ/NDACC stations and Cathy Boone at the French

AERIS/ESPRIdatacentrehttp://www.cds-espri.ipsl.upmc.

fr/forprovidingMIMOSA,REPROBUSandECMWFanalyses

and reanalyses. The SAOZ measurements at Eureka/

CANDAC are supported by the Canadian Space Agency.

The SAOZdata are available at the NDACC data centre

http://www.ndsc.ncep.noaa.gov/.Thisresearchis

suppor-ted by the NDACC French programme funded by the

‘‘Institutnationaldessciencesdel’Univers’’(CNRS/INSU), the‘‘Centrenational d’e´tudes spatiales’’(CNES) and the polarInstitutePaul-E´mile-Victor(IPEV),whichare

grate-fully acknowledged. The SLIMCAT modelling work is

supportedbytheNationalCentreforAtmosphericScience (NCAS).

References

Adams,C.,Strong,K.,Zhao,X.,Bassford,M.R.,Chipperﬁeld,M.P.,Daffer, W.,Drummond,J.R.,Farahani,E.,Feng,W.,Fraser,A.,Goutail,F., Manney,G.L.,McLinden,Pazmino,A.,Rex,M.,Walker,K.A.,2012.

Severeozonedepletionassessedwith11yearsofozone,NO2and

OClOmeasurementsat808N.Geophys.Res.Lett.39,L95806,http:// dx.doi.org/10.1029/2011GL050478.

Arnone,E.,Castelli,E., Papandrea,E.,Carlotti,M.,Dinelli,B.M., 2012. Extreme ozonedepletion inthe2010–2011Arcticwinter strato-sphere asobserved by MIPAS/ENVISAT using a 2D tomographic approach. Atmos. Chem. Phys. 12, 9149–9165, http://dx.doi.org/ 10.5194/acp-12-9149-2012.

Bednarz,E.,Maycock,A.,Abraham,N.L.,Braesike,B.,Dessens,O.,Pyle,J.A., 2016.FutureArcticozonerecovery:theimportanceofchemistryand dynamics.Atmos.Chem.Phys.16,12159–12176,http://dx.doi.org/ 10.5194/acp-16-12159-2016.

Bohlinger,P.,Sinnhuber,B.M.,Ruhnke,F.,Kirner,O.,2014.Radiativeand dynamicalcontributionstopastandfutureArcticstratospheric tem-perature trends. Atmos. Chem. Phys. 14, 1679–1688, http:// dx.doi.org/10.5194/acp-14-1679-2014.

Boynard,A.,Hurtmans,D.,Garane,K.,Goutail,F.,Hadji-Lazaro,J., Kou-kouli,M.E.,Wespes,C.,Keppens,A.,Pommereau,J.-P.,Pazmino,A., Balis,D.,Loyola,D.,Valks,P.,Coheur,P.-F.,Clerbaux,C.,2018. Valida-tion of the IASI FORLI/Eumetsat ozone products using satellite (GOME-2),ground-based(Brewer–Dobson,SAOZ)andozonesonde measurements. Atmos. Meas. Tech. Discuss., http://dx.doi.org/ 10.5194/amt-2017-461(inreview).

Chipperﬁeld,M.P.,1999.Multiannualsimulationswitha Three-Dimen-sionalChemicalTransportModel.J.Geophys.Res.104,1781–1805.

Chipperﬁeld,M.P.,Feng,W.,Rex,M.,2005.Arcticozonelossandclimate sensitivity:updatedthree-dimensionalmodelstudy.Geophys.Res. Lett.32,L11813,http://dx.doi.org/10.1029/2005GL022674. Dhomse,S.S.,Kinnison,D.,Chipperﬁeld,M.P.,Salawitch,R.J.,Cionni,I.,

Hegglin,M.I.,Abraham,N.L.,Akiyoshi,H.,Archibald,A.T.,Bednarz, E.M.,Bekki,S.,Braesicke,P.,Butchart,N.,Dameris,M.,Deushi,M., Frith,S.,Hardiman,S.C.,Hassler,B.,Horowitz,L.W.,Hu,R.-M.,Jo¨ckel, P.,Josse,B.,Kirner,O.,Kremser,S.,Langematz,U.,Lewis,J.,Marchand, M.,Lin,M.,Mancini,E.,Mare´cal,V.,Michou,M.,Morgenstern,O., O’Connor,F.M.,Oman,L.,Pitari,G.,Plummer,D.A.,Pyle,J.A.,Revell, L.E.,Rozanov,E.,Schoﬁeld,R.,Stenke,A.,Stone,K.,Sudo,K.,Tilmes,S., Visioni,D.,Yamashita,Y.,Zeng,G.,2018.Estimatesofozonereturn datesfromChemistry-ClimateModelInitiativesimulations.Atmos. Chem.Phys.18,8409–8438, http://dx.doi.org/10.5194/acp-18-8409-2018.

Goutail,F., etal.,1999.DepletionofcolumnozoneintheArctic1993– 1994and1994–1995.J.Atmos.Chem.32,1–34.

Grifﬁn,D.,Walker,K.A.,Wohltmann,I.,Dhomse,S.S.,Rex,M.,Chipperﬁeld, M.P.,Feng,W.,Manney,G.L.,Liu,J.,Tarasick,D.,2018.Stratospheric ozonelossintheArcticwintersbetween2005and2013derivedwith ACE-FTS measurements. Atmos. Chem. Phys. Discuss., http:// dx.doi.org/10.5194/acp-2017-1075(inreview).

Hansen,G.,Hoppe,U.-P.,1997.LidarobservationsofPolarStratospheric Cloudsandstratospherictemperaturesinwinter1995/96over north-ernNorway.Geophys.Res.Lett.24,131–134.

Hardiman,S.C.,Butchardt,N.,Calvo,N.,2014.Themorphologyofthe Brewer–Dobsoncirculationanditsresponsetoclimatechangein CMIP5simulations. Q.J. R. Meteor.Soc. 140,1958–1965,http:// dx.doi.org/10.1175/gj.2258.

Langematz,U.,etal.,2014.FutureArctictemperatureandozone:therole ofstratosphericcompositionchange.J. Geophys.Res.119,2092– 2112,http://dx.doi.org/10.1002/2013JD021100.

Lefevre,F.,Brasseur,G.P.,Folkins,I.,Smith,A.K.,Simon,P.,1994. Chemis-tryofthe1991–1992stratosphericwinter:three-dimensionalmodel simulations.J.Geophys.Res.99,8183–8195.

Lindenmaier,R.,Strong,K.,Batchelor,R.L.,Chipperﬁeld,M.P.,Daffer,W.H., Drummond,J.R.,Duck,T.J.,Fast,H.,Feng,W.,Fogal,P.F.,Kolonjari,F., Manney,G.L.,Manson,A.,Meek,C.,Mittermeier,R.L.,Nott,G.J.,Perro, C.,Walker,K.A.,2012.Unusuallylowozone,HCl,andHNO3column

measurementsatEureka,Canadaduringwinter/spring2011.Atmos. Chem.Phys.12,3821–3835, http://dx.doi.org/10.5194/acp-12-3821-2012.

Manney,G.L.,Lawrence,Z.D.,2016.Themajorstratosphericﬁnal warm-ingin2016:dispersalofthevortexairandterminationofArctic chemicalozoneloss.Atmos.Chem.Phys.,http://dx.doi.org/10.5194/ acp-16-15371-2016.

Manney,G.L., etal.,2011.UnprecedentedArcticozonelossin2011. Nature478,469–475,http://dx.doi.org/10.1038/nature10556. Matthias,V.,etal.,2016.Theextraordinarilystrongandcoldvortexinthe

earlywinter2015/2016.Geophys.Res.Lett.4312,1287–1294,http:// dx.doi.org/10.1002/2016GL071676.

Morgenstern,O., etal.,2017.Ozonesensitivitytovaryinggreenhouse gasesandozonedepletingsubstancesinCCMIsimulations.Atmos. Chem.Phys.,http://dx.doi.org/10.5194/acp-2017-565.

J.-P.Pommereauetal./C.R.Geoscience350(2018)347–353 352

(8)

Pommereau,J.-P.,Goutail,F.,1988.O3andNO2Ground-Based Measure-mentsbyVisibleSpectrometryduringArcticWinterandSpring,1988. Geophys.Res.Lett.15,891–894.

Pommereau,J.-P., etal.,2013.Whyunprecedentedozonelossinthe Arcticin2011?Isitrelatedtoclimaticchange?. Atmos.Chem.Phys. 13,5299–5308.

Rex,M.,Salawitch,R.J.,vonderGathen,P.,Harris,N.R.P.,Chipperﬁeld, M.P.,Naujokat,B.,2004.Arcticozonelossandclimatechange. Geo-phys.Res.Lett.31,L04116,http://dx.doi.org/10.1029/2003GL018844. Rex,M.,vonderGathen,P.,Woltmann,I.,2016.Arcticozonelossduring theexceptionallycoldwinter2015/2016asdeterminedbyMatchand theATLASmodel,Quad.OzoneSymp.,Edinburgh..

Sinnhuber,B.M.,Stiller,G.,Ruhnke,R.,vonClarmann,T.,Kellmann,S., Aschmann, J.,2011. Arctic winter 2010/2011atthe brinkof an

ozonehole. Geophys. Res. Lett. 38, L24814, http://dx.doi.org/ 10.1029/2011GL049784.

Solomon,S.,Ivy,D.J.,Kinnison,D.,Mills,M.J.,NeelyIII,R.R.,Schmidt,A., 2016.EmergenceofhealingintheAntarcticozonelayer.Science, http://dx.doi.org/10.1126/science.aae0061.

Sun,L.,Deser,C.,Polvani,L.,Thomas,R.,2014.InﬂuenceofprojectedArctic seaicelossonpolarstratosphericozoneandcirculationinspring. Environ.Res.Lett.9,084016.

Waters, J.W., etal., 2006. TheEarth Observing System Microwave LimbSounder(EOSMLS)ontheAurasatellite.IEEETrans.Geosci. Remote Sens. 44 (5), 1075–1092, http://dx.doi.org/10.1109/ TGRS.2006.873771.

WMO(WorldMeteorologicalOrganization),2014.ScientiﬁcAssessment ofOzoneDepletion:2014,Geneva,Switzerland. (416p.).