Post on 10-Aug-2020
ENVRIplus DELIVERABLE
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A document of ENVRIplus project - www.envri.eu/envriplus
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654182
D4.1 Report on crosscutting issues,
associated existing monitoring capacit ies and selected open case studies result ing
from the Interdisciplinary workshop
WORKPACKAGE4–JointoperationsacrosstheResearchInfrastructuredomainsLEADINGBENEFICIARY:INRA
Author(s): Beneficiary/Institution
AbadChabbi,CathrineLundMyhre,GregoryStarr,HenryLoescher,NicholasMeskhidze,NicolasBellouin,SilvanoFares,WilfriedWiniwarter,
AbadChabbiINRA[ANAEE],KarineSelegeriCNRS[ACTRIS],Jean-DanielParisCEA[ICOS],VitoVitale+MauroMazzolaCNR[SIOS]MichaelCunliffeMBA[EMBRC],RichardLampittNERC/NOC,SylviePouliquenEURO-ARGO,MichaelMirtlEAA,CathrineLundMyhre(NILU)
Acceptedby:Jean-DanielParis(WP4leader
Deliverabletype:REPORT
Deliverableduedate:31.10.2016/M18
ActualDateofSubmission:31.10.2016/M18
Ref. Ares(2016)6209899 - 31/10/2016
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ABSTRACTTheworkshopaimstobuildbridgesacrossnetworksofobservatoriesandtodeterminehowemergingenvironmentalresearchquestionscanbenefitfromthesenewinteractions.Theworkshopidentifykeyinterdisciplinarychallengesacrosssubdomainsthatwewilladopt,promoteandimplementwithintheENVRIplus.Specialattentionwasgivenoncombiningdifferentnetworksofobservatories,focusingonafewcurrentscientificissuesforsocietalbenefit.
Projectinternalreviewer(s):
Projectinternalreviewer(s): Beneficiary/Institution
WernerLeoKutsch UniversityofHelsinki/ICOSHeadOfficePOBox4800014UniversityofHelsinkiFinland
Jean-DanielParis
ICOS-RAMCESLaboratoiredesSciencesduClimatetdel'Environnement,CEASaclay,OrmedesMerisiers91191GifsurYvette,France
Documenthistory:
Date Version
8.10.2016 Draftforcomments
27.10.2016
Correctedversion
31.10.2015
AcceptedbyWPJean-DanielParis(WPLeader)
DOCUMENTAMENDMENTPROCEDUREAmendments,commentsandsuggestionsshouldbesenttotheauthors(AbadChabbi,abad.chabbi@inra.fr)
TERMINOLOGYAcompleteprojectglossaryisprovidedonlinehere:https://envriplus.manageprojects.com/s/text-documents/LFCMXHHCwS5hh
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PROJECTSUMMARYENVRIplusisaHorizon2020projectbringingtogetherEnvironmentalandEarthSystemResearchInfrastructures,projectsandnetworkstogetherwithtechnicalspecialistpartnerstocreateamorecoherent,interdisciplinaryandinteroperableclusterofEnvironmentalResearchInfrastructuresacrossEurope.Itisdrivenbythreeoverarchinggoals:1)promotingcross-fertilizationbetweeninfrastructures,2)implementinginnovativeconceptsanddevicesacrossRIs,and3)facilitatingresearchandinnovationinthefieldofenvironmentforanincreasingnumberofusersoutsidetheRIs.
ENVRIplusalignsitsactivitiestoacorestrategicplanwheresharingmulti-disciplinaryexpertisewillbemosteffective.TheprojectaimstoimproveEarthobservationmonitoringsystemsandstrategies,includingactionstoimproveharmonizationandinnovation,andgeneratecommonsolutionstomanysharedinformationtechnologyanddatarelatedchallenges.ItalsoseekstoharmonizepoliciesforaccessandprovidestrategiesforknowledgetransferamongstRIs.ENVRIplusdevelopsguidelinestoenhancetransdisciplinaryuseofdataanddata-productssupportedbyapplieduse-casesinvolvingRIsfromdifferentdomains.Theprojectcoordinatesactionstoimprovecommunicationandcooperation,addressingEnvironmentalRIsatalllevels,frommanagementtoend-users,implementingRI-staffexchangeprograms,generatingmaterialforRIpersonnel,andproposingcommonstrategicdevelopmentsandactionsforenhancingservicestousersandevaluatingthesocio-economicimpacts.
ENVRIplusisexpectedtofacilitatestructurationandimprovequalityofservicesofferedbothwithinsingleRIsandatthepan-RIlevel.Itpromotesefficientandmulti-disciplinaryresearchofferingnewopportunitiestousers,newtoolstoRImanagersandnewcommunicationstrategiesforenvironmentalRIcommunities.Theresultingsolutions,servicesandotherprojectoutcomesaremadeavailabletoallenvironmentalRIinitiatives,thuscontributingtothedevelopmentofacoherentEuropeanRIecosystem.
TABLEOFCONTENTS
INTRODCUCTION..................................................................................................41. Nitrogen,fromagriculturalfieldstothecoastalocean:theconceptofnitrogenbudgetsandcorollaryresearchinfrastructurescontributions..............52. Phytoplanktonbloomsfromcoastaltoopenocean....................................62.1OceanicEmissions,MarineAerosolsandClouds.......................................62.2ObservationsforEarthSystemmodelling..................................................7
3. Arcticobservation,withspecialfocusonCH4.............................................94. SimulatingandmonitoringO3andCO2deposition/coupling/interaction 11CONCLUSIONS....................................................................................................12IMPACTONPROJECT......................................................................................12IMPACTONSTAKEHOLDERS...........................................................................12
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Reportoncrosscuttingissues,associatedexistingmonitoringcapacitiesandselectedopencasestudiesresultingfromtheInterdisciplinaryworkshopINTRODCUCTIONTheScienceAcrossObservatoryNetworksinternationalworkshopwasheldinZandvoort,
NetherlandsonMay9th,asparttheENVRIPlusWeek.TheworkshopwascoordinatedbyacommitteeincludingAbadChabbi,INRA,France;AriAsmi,U.Helsinki,FinlandandJean-DanielParis,CEA,France)andaScientificCommittee(included;AbadChabbi,INRA,France;HankLoescher,NEON,USA;GelsominaPappalardo,CNR,Italy;Jean-DanielParis,CEA,France;Jean-FrançoisRolin,IFREMER,France;KarineSelegri,CNRS,France;MichaelCunliffe,MBA/NOC,UKandThomasDirnboeck,Umweltbundesamt,Austria.
Thegoaloftheworkshopwastobuildbridgesandassesssynergiesacrossobservatorynetworks--andhowemergingenvironmentalresearchquestionsstandtobenefitfromsuchinteractions.Keyinterdisciplinarychallengeswereidentifiedacrossscientificsubdomains,aswellasstrategicopportunitiesacrossResearchInfrastructures.Specialattentionwasgiventocombiningdifferentobservatorynetworkstoadvancefrontiersciences,focusingonthepre-selectedscientificthemesidentifiedbyENVRI+communitiesmembersintheformofthefollowing4casestudies:
1. Nitrogenfromthefieldtothecoastalocean2. Phytoplanktonbloomsfromcostaltoopenocean3. Arcticobservation,withspecialfocusonCH44. SimulatingandmonitoringO3andCO2deposition/coupling/interaction
Morethan70participantswereinattendancewhentopkeynotespeakerswereaskedtoprovideacomprehensiveandin-depthanalysisofeachofthecasestudiesthatincludedwhatmaybenewdirectionsforfutureresearchandinfrastructures.Eachcasestudypresentationledtoimportantfollow-updiscussionsregardingi)whereresearchinfrastructureshaveyettobecreatedtocombinesubdomains(gapanalyses)andii)wherefurthercross-disciplinarycollaboration,interoperabilityandinfrastructureimprovementsmayberequiredforexistinginfrastructurestobesuccessful.
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1. Nitrogen,fromagriculturalfieldstothecoastalocean:theconcept
ofnitrogenbudgetsandcorollaryresearchinfrastructurescontributions
Overtherecentyears,nitrogenbudgetshavebeendevelopedinsuchawayastobecomeapracticalpolicy-makingtool.Originallyacompilationofspecificyetunconnectedindicators,nationalNbudgetsarenowcomprisedofacompletesetofNflowsthroughanation’s“metabolism”.Comprehensiveoperationaldatacollectionandcompilationhasnotbeenperformedsystematicallyyet.Growingnationalobligationstoinventoryairpollutantsandgreenhousegasemissionsalreadynowprovidethelargestshareofinformationneeded,thusfullimplementationwillrequireratherlittleextraeffort.
Intheory,Nbudgetsarefoundedontheconservationofmatter.However,morethan99%ofNstocksmaybesafelyignored,asitisunreactiveintheformofmolecularN2(themainconstituentoftheatmosphere).The“Activation”ofNisthecentral,energy-intensivestepoftheprocess,sothatonlythereactiveN(Nr)needstobeconsideredinthebudgetsofstocksandflows.SuchNrbudgetshaveprovenvaluableinprioritizingNflowsandbetterunderstandingtemporaltrendsandspatialdistributionamongecosystemtypes.
Whiletheconceptandguidancearelargelyinplace,thefewnationalbudgetscurrentlyavailablearescientificexercises.SupportfromenvironmentalagenciesandadministrationwillberequiredtocollectdataneededforabetterunderstandingoftheanthropogenicimpactontheNcycle.Thisbasicknowledgewillallowtodesignabatementactionplansaimingforalleviatingenvironmentaldamage(humanhealth,biodiversity,climatechange...)generatedbyanexcessNrintheenvironment.
InfrastructuresareinplaceintheEUtoroutinelymonitorNrcompoundsintheatmosphere(NOx,PM)aswellasingroundwater(nitrate)aspartofEUenvironmentallegislation.Talltowerstationshavebeenhavebeenlinkedtoallowinversemodellingofgreenhousegasemissions(asofN2O)inscientists’activities(TTORCH,InGOS)whichcanbeextendedbysatelliteinformationonNOxandN2OfromplatformslikeENVISAT.Biosphere-pedosphereinteractiononNrcompoundsinsoilsandgroundwaterarebeinginvestigatedinnaturalecosystems(LTER)butaremuchmorerelevantinagriculturalsystemsthatareexposedtohighlevelsoffertilizerN.ManyagriculturalresearchinstitutesoverEuropesportcollectingthisinformation,butlittlesystematicinteractioncanbeobservedacrossnationalborders.Alltheseexistingactivitiesaresectoral,butrequireanoverarchingapproach.Nitrogenbudgetsasdescribingallthelinkingelementsbetweenpoolsorsectorscanserveasthelinkurgentlyneeded.
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2. Phytoplanktonbloomsfromcoastaltoopenocean
2.1OceanicEmissions,MarineAerosolsandClouds Atmosphericaerosolsplayalargeroleinairqualityandhuman-inducedclimatechange.Afterdecadesofresearch,aerosol–cloudinteractions(ACI)remainthelargestsourceofuncertaintyincurrentestimatesofglobalradiativeforcing.Thisismainlyduetothefactthataerosols,cloudsandecosystemelementsareintricatelylinkedintheEarthSystem,viamultipleinterrelatedforcingandfeedbacks.NarrowingtheuncertaintiesinACIwouldthereforerequireconsideringallelementstogether,frombothamechanisticandobservationalstandpoint.Becauseeffectsonclimateareestimatedfromthedifferencebetweenmodelsimulations,present-dayobservationsandpreindustrialaerosolandprecursoremissions,anaccuraterepresentationofnumberconcentrationsofcloudcondensationnuclei(CCN)andicenucleatingparticles(INP)associatedwithbothnaturalbackgroundandman-madeaerosolsseparatelyiscriticalindevelopingabetterassessmentofanthropogenicaerosoleffects.Asmarineaerosolscontributesubstantiallytothepreindustrial,naturalbackgroundwhichprovidesthebaseline–ontopofwhichanthropogenicforcingshouldbequantified–andbecausetheoceancoversover70%oftheEarth’ssurface,therepresentationofmarineaerosolsinclimatemodelsstronglyinfluencesthepredicteddirectandindirectimpactsofanthropogenicaerosolsonclimate.
CurrentEarthSystemSciencemodelsexhibitalargediversityintheirrepresentationofmarineaerosolsourcesandsinks,aswellastheprocessesbywhichtheseaerosolsimpactcloudwaterandiceformation.Thisdiversityisdue,inpart,tothelackofmeasurementsneededtoconstrainthemodelsandtheabsenceofacentralizednetwork,whereallavailabledatamaybeaccessed.Measurementsofmarineaerosolsarechallengingbecauseoftheirvastspatiotemporalvariability,lowconcentrationandtotheinherentdifficultyinreproducingthephysicalscalesinwhichtheyoccur.However,eventheavailabledataishardtousebecauseofdifferencesintheconditionsiswhichtheyarecollectedandthemethodologyandinstrumentationemployedbydifferentinvestigators.Today,keyquestionsremainunansweredregardingthesourcesandsinksofmarineaerosolsandtheirimpactsonclouds,limitingourabilitytoquantitativelypredicthowtheclimatewillrespondtocontinuedandincreasinggreenhouse-gasandfine-particleemissionsinthefuture.
WeproposethatENVRI+developtheintegrativeframeworktocompileandmakeaccessibleallavailablesatellite-borne,ambientandlaboratorydataofmarineaerosolchemicalcomposition,CCNandINPs,meteorological,oceanphysicochemicalandbiologicalstate,aswellasthetracegasconcentrationsaffectingparticleproductionandtheoxidizingpotentialofthemarineatmosphere.Thisisnoteasy;thecompilationofsuchcomprehensivedatasetsinaformatsuitableformodel/datacomparisonwouldrequireacoordinatedandmultidisciplinaryresponseandtheinvolvementandexpertiseofabroadrangeofscientificcommunities.However,oncethedataiscategorizedandmadeaccessiblethroughauser-friendlynetwork,thescientificcommunitystandstosavevastamountsoftimeandenergybyavoidingunnecessaryduplications.Theexistenceofsuchdatasetswouldalsoallowresearcherstoconcentrateondataanalyses,capturingpotentiallyimportantradiativeandclimatefeedbacksanddevelopingsubsequentdiscoveries.
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2.2ObservationsforEarthSystemmodelling
Theuseofmodelstorepresentourunderstandingoftheclimatesysteminvolvescouplingradiationandwatercycleparameters(includingcloudformationandthecryosphere),withatmosphericandoceanicdynamics.Theoverarchinggoalistodevelopaclimatebaselinetobetterassesstheimpactofperturbations–anthropogenic,solar,astronomicalorvolcanic–onclimateandexplainnon-linearbehaviorsinvariousfeedbackmechanisms(which,inturn,couldenhanceorlimitsaidperturbations).
Inthepast,climatemodelswerelimitedintheirabilitytorepresentfeedbacksbecausevariousaspectsofthesystem–suchasatmosphericcompositionorvegetation–wererepresentedasfixedstaticentities.However,theEarthSystem(ES)modelsthathaveemergedoverthepastdecadeincludetherepresentationofdynamicclimatefeedbackinrelationstothecarboncycle,atmosphericaerosolsandchemistry.ThankstoESmodelling,wecannowstudyclimate-drivenchangesinoceanicCO2solubility,thebiologicalcarbonpump,landproductivitydistribution,soilrespirationandtheirultimateroleinclimatechange.
Morerecently,ESmodellinghasfocusedonvegetationandsoilsemissions(volatileorganiccompounds,methane,andnitrogenoxides)andcouplingsbetweenatmosphericcompositionandradiation-drivencomponents,suchasvegetationandcoralgrowth,evapotranspirationandriverrun-off,monsoonsystemsandpermafrostthawing.State-of-the-artESmodelstypicallyincluderepresentationsofthecarboncycle,ozonechemistry,wetlandsandpermafrost,sulfate,carbonaceous,mineraldustsandsea-saltaerosols.Themostsophisticatedmodelsalsoincludeoceanbiogeochemistry,stratosphericozonechemistryandfiremodelling,aswellasnitrateandsecondaryorganicaerosols.Researchershaveyettodevelopsatisfyingrepresentationsofthenitrogencycleandoceancalciumcarbonates,however.
Itoftentakesupto5yearstoimprovesuchmodels,seeingasextensiveobservationisrequiredtoprovideinsightsintotheprocess,developnumericalparameterizationsandultimatelytestandvalidatesubsequentresultsagainstin-situobservations.Comparativemodel-dataevaluationsmayincludestatisticsonthefrequency,strengthandtrendsofperturbations,aprioriandaposteriparameterdistributions,uncertaintybudgetcomparisons,etc...Thisensuresthatthemodelaptlyreflectstheclimatebaselineandperturbations—orinformsgapsintheory,observationsormodel(s).Spatialandtemporalscalesmismatchesareoftenachallengeinsuchcomparisons,somethingtheresearchcommunityhasnotbeenabletofullyresolve.Observationstypicallycoverhundredsofkilometersandlongtime-seriestofullysupportmodelvalidation;incontrast,processunderstandingisoftenbasedonveryfinescales.
Modelersareoftenpragmatic,ifnotopportunistic,whenseekingobservationdatasetstosupporttheirmodeldevelopmentandpredictions.Table1providesanon-exhaustivelistofdatasourcesfrequentlyusedbyatmosphericcompositionmodelers.Nevertheless,initiativesthelikesoftheObservationsforModelIntercomparisonProjectsandAerosolComparisonsbetweenObservationsandModelsprojectstrivetomakeobservationseasiertousebyprovidingmodelerswithdatasetsingriddedform,astimeseriesandinmodel-friendlyformats.BecausemanyoftherelevantprocessesoccurininterfacewithvariousEScomponents,
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ground-basedandin-situobservationsareoftenmostvaluabletomodelers,insofarastheyalsoinformonprocessesinvisibletospace-borneremotesensors.Forthatreason,astrongcaseshouldbemadetobetterpositionENVRI+networksintheglobalclimatemodellinglandscape.
Climatevariables Examplesofdatasource
Surfaceconcentrations(total,e.g.PMandspeciated)
Airqualitymonitoringnetworks(CREATE,EMEP,IMPROVE,NARSTO,STN),GAW-WDCAsites,fieldcampaigns
Aerosolopticaldepth Ground-basedsunphotometernetworks(AERONET),satelliteretrievals(MODIS,MISR,POLDER/PARASOL,VIIRS,AVHRR),reanalyses(MACC,NCEP),fieldcampaigns
Aerosolsizedistribution,fine-modefraction,Angstromexponent
EUSAAR/GUANsupersites,ground-basedsunphotometernetworks(AERONET),satelliteretrievals(MODIS,MISR,POLDER/PARASOL,VIIRS),fieldcampaigns
Totalcolumnozone Surfacespectrophotometernetwork(GMD),satelliteretrievals(SCIAMACHY,GOME,OMI)
Greenhousegases Databases(AGAGE,ESRL),satelliteretrievals(GOSAT,IASI,MOPITT,TROPOMI)
Verticalprofilesofaerosolsandozone
Lidarnetworks(EARLINET,MPLNET),satelliteretrievals(GOME,OMI),activeremotesensing(CALIPSO),aircraftcampaigns(HiPPO)
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3. Arcticobservation,withspecialfocusonCH4
TheArctichasbeenshowntohaveincreasedintemperatureby0.6oCelsiuseachdecadeforthepast30years.Thischangeisapproximatelydoubletheglobalaverageandisprojectedtoincreaseatevenfasterratesinthefuture(IPCC2013)aspartofaphenomenonreferredtoastheArcticamplification.Thiswillhaveunprecedentedeffectsonboththeoceanicandcontinentalsystemsoftheregionandmitigationhasbecomealargescientificandsocietalimperative—particularlyforArcticnativeswhorelyonsubsistenceharvests(fish,caribou,seal,walrus,waterfowl,etc.)andwhoseshorelineandhuntingandfishinghabitatarerapidlydisappearing.
IntheArcticterrestrialenvironment,permafrostdynamicsareattheheartofsuchchanges.Thetop30orsocentimetersofpermafrostnaturallythaweachyearduringthesummer.However,duetoincreasedtemperatures,thethawingofthepermafrostreachesdeepersoildepths,directlyaffectinganumberofecologicalprocesses,including
i. changesinthetemporaldynamicsanddepthofthethawoftheactivelayer,resultingin‘old’carbontorespireandeffluxmoreintotheatmosphere;
ii. subsequentchangesinsurfacehydrology;
iii. alargeportionof‘old’carbonbeingsubjecttoanaerobicmetabolismpathways,whichincreaseCH4efflux;
iv. additionalnutrientavailabilitycausingshiftsinplantcommunitycomposition,peakproductivityandwoodyencroachment;
v. increasedstorageofgroundheatfluxanddarkeralbedo,whichinturninitiateconvectiveboundarylayers,lightningandlightning-inducedtundrafires(furtherconvertingcarbonintotheatmosphere);
vi. anincreaseinthelengthofsummerandinducedseasonal‘edgeeffects’onecosystemprocesses;
vii. lakeCH4productionundericeandtheconcentrationofCH4‘bubbles’aswellas
viii. strongevidenceofCH4consumptionbysoils.
ThecontinentalscalespatialdynamicsofCH4athighlatitudesarealsopoorlyunderstood.Modelandmeasuredresultsshow‘tippingpoint’temperatures–inwhichmasspermafrostthawsandCH4productionoccurs–differintheNorthAmericancontinentandinAsia.Moreover,meanannualtemperaturesinNorthernSiberiaareincreasing,whiletheyarecoolinginSouthernSiberiabutthemechanismatplayisnotknown.
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MethanehasahigherglobalwarningpotentialthanCO2,circa28timesstrongerovera100-yearperiodandwithanaverageten-yearlifetimeintheatmosphere.TheprocessesresponsibleforthedevelopmentofCH4fromnaturalsourceshaveyettobeexplained,thoughtheyappeartobecloselylinkedtotemperatureandprecipitationandvulnerabletoclimatechange.SuchatmosphericprocessesareconsiderableandmorecomplexthanforCO2.Assuch,theprocessesanddriversthatgovernmethanogenesisandCH4reductionandconsumptionarestillthesubjectofactiveresearch.Alsohamperingground-basedmeasuresisourinabilitytodiscerntowhichextentdifferentphysicalmechanismstransportCH4fromthesoilandthebiosphereintotheatmosphere(i.e.,ebullition,diffusion,aerenchymapumping,orpressurepumping).NewaerialmeasuresofCH4derivedfromtheCARVEprojectdemonstrateemissionsarenotregionallyhomogenous,butshowhigherconcentrationsalonglargeriverbedsanddifferentgeologicsubstrates,whichthemselveswouldrequireadditionalresearchintheirownright.
ThecurrentterrestrialinfrastructureintheArcticislimited,primarilyduetoroughlogisticalandclimaticconditions.ConstrainedtoaselectnumberofcountriestheyincludetheInteract(pan-Arcticfieldstations),theITEX(pan-Arcticheatingexperiment(nowretired),theSwedishICOStower-basedproject,theNorwegianICOSstudyoffluxesfromterrestrialregions,oceanandatmosphericlevels,theNSFNEONandUSNSFAEONtower-basedprojects,theUSDOENGEEbio-geochemistrystudy,theUSNASACarveboundarylayerflightsresearch(nowretired,theUSNASAABOVEintegratedaircraftandtowersproject(intheUSandCanada)andtheEMSOEuropeanMultidisciplinarySeafloorandwater-columnObservatory.
IntheArcticoceanicandcoastalenvironments,arelativelynewsourceofCH4hasbeenreportedinmethanehydrateproduction,whichisventingthroughtheoceansandcouldpotentiallysignificantlycontributetoatmosphericconcentrations.TherearelargeamountsofCH4storedintheworld’soceansandseafloor(particularlyathigher,colderlatitudes)inasolidhydrateform(clathrates).Theyarethoughttobelocatedonoceanfloorswheresedimentscanbio-accumulateandassuch,areextremelyspatiallyheterogeneousanddifficulttodetect.Itisconsideredcoldwatertemperatures(slowreactionrates),nearcoastalareas(bio-accumulationsources)anddeepwater(pressure)areessentialtotheformationofthesedeposits.Butasoceantemperaturewarm,thereisrealconcernregardingadditionalandpossiblyrapidreleaseofsolidCH4duetoitsdestabilizationintogaseousform.AttemptstoestimatemethanehydratesfluxesareevenmoredifficultthanterrestrialCH4research,ashydratesrequireships,shiptimeandseafloorobservatories(EMSO).Becauseofsuchconstraints,measuresarecollectedthroughad-hoccruisesandevenwhenlargedepositsareformed,theirfluxesintotheatmospherearespatiallyheterogeneous.However,Methanehydratesbeingapotentialenergysource,,energyexplorationmayserendipitouslyhelpscientistsaccessandstudytheseCH4reserves.
Neverthelesslong-term,consistentmeasurements(groundandairandsea)arelacking,asareconsistentCH4measurementmethodologies(i.e.,CH4filtering,gap-fillingprocedures,spatialdistributionoftalltowerswhichcurrentlydonotexistandflasksampling,etc...).ThelogisticstoconductscienceintheArcticareclearlychallenging,withlimitedaccess,coldtemperaturesand24hofdaylightduringthesummer(andconverselyinthewinter).Theseresearchquestionsanswerstrongsocietalimperatives,andwouldwarrantthereleaseofnewandimmediateresourcesdespitethechallengesfacingresearchersworkingintheArctic.CH4releasesintotheArcticwayhaveinternationalimplicationsforoursociety,asmanycircumpolarcountrieshaveastakeinthisissue.ThroughtheArcticCouncilandinaccordancewiththeGalwaydeclaration,
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intergovernmentalcooperationtoolsshouldbeexploitedtoovercomelegalandgeopoliticalbarriersandconducttheappropriateresearch.
4. SimulatingandmonitoringO3andCO2deposition/coupling/interaction
Ozoneisahighlyreactive,toxicoxidantforplantsandisresponsibleforadecreaseinthecarbonassimilationofplantecosystems.Thissecondarypollutantisphotochemicallyformed,especiallyinareasinwhichhighUVradiationsareassociatedtohightemperaturesandthepresenceofvolatileprecursors,suchasNOxandVOCs.
Thismoleculeispresentintheatmosphereintraceconcentrations(lessthan100ppbv)andiscapableofinhibitingcarbonassimilationinagriculturalandforestecosystems.Ozoneisalotmoredifficulttomeasurethanothernon-reactivegreenhousegases.However,UV-basedandnewchemiluminescencesensorsenablepreciseandfastmeasurementsandtheiruseinexperimentalinfrastructuresishighlydesired.
Directfluxmeasurementsinthefield,usingmicrometeorologicaltechniquesinassociationwithlatentheatfluxmeasurements,allowforthepartitionofozonefluxesintodifferentsinksonthesoil-plantcontinuum:i)Stomata,ii)adsorptiononplantsurfacesandiii)gas-phasereactionswithreactiveVOCsandNOx.Experimentalevidencesuggestsstomataaloneareresponsiblefor40to80%oftheozoneremovedbyvegetation.TroposphericO3formationgeneratedbyphotochemicalreactionsinvolvingBVOCandO3mustbealsotakenintoaccountinO3budgets.
Sofar,ozoneriskassessmentshavebeenbasedonmanipulativeexperiments.Presentregulationsinassessingcriticalozonelevelsaremostlybasedonestimatedaccumulatedexposureoverathresholdconcentration.Thereishoweverascientificconsensusonfluxestimatesbeingmoreaccurate,becausetheyincludeplantphysiologyanalysesanddifferentenvironmentalparametersthatcontroltheuptake–andnotjusttheexposure--ofozone.
Long-termEddyCovariancemeasurementsofferagreatopportunitytoestimatecarbonassimilationathightemporalresolutions,soastostudytheeffectofclimatechangeonphotosyntheticmechanisms.Recentstudiessuggestwaveletandmultivariatestatisticalanalysesmaysupportourinterpretationofozonedamagetovegetation–providedozonecovariationswithenvironmentalfactors(suchaslightandtemperature)areproperlytakenintoaccount.
Whilethescientificcommunityisinvolvedinestablishinglong-termresearchinfrastructurestomeasurecarbonassimilationinresponsetoclimatechanges(e.g.ICOSnetwork),theadoptionoflow-costfastozonesensorsforEddyCovariancemeasurementswouldconstituteavaluableeffortinbetteringourunderstandingofcarbonassimilationinresponsetoenvironmentalstresses.
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CONCLUSIONS
IMPACTONPROJECTTheworkshopwasakeyelementinfindingoutsomeofthemostpressingscientificquestionswhichcouldbeansweredviainterdiciplinarycollaboration.TheworkshopresultsareparticularlyusefulfortherestoftheThemeIworkpackagesintechnicaldevelopmenprioritiesandtotheclusterstrategicprioritizationactionsinWP18.
IMPACTONSTAKEHOLDERSThedeliverableisalsoimportantfactorfortheRIprioritization,particularlyinthecontextofinternationalandcross-diciplinarycollaboration.