ÿWPC+ í#©C4X'÷Ær¢ vB|Z-4!+ ,gX%÷ÆÖ›g«¯¯¡°äŠ 0füdB “Iž–Že ‚æQRw¡É§¯Î®kêT$þÓ >äcÿÊ{PŒŒM ÞEA`ƒ‹¦¸a.d‘åêðŸƒBáNC•ÿ^ä90NA·²üÅݳ4ßJèa1B,XîÂ}ŠïôÝÚ &]NSLÞ¸Ï -¥ðkHâCPB£dN3×\i\N…È!­ §çF<ÙÆYA=Á¦ÒÏü¸¡–Î%{Iæã@­è ÀEÂÇ ýÈ@D°éÓìI³s¸I…ébïìæºÄ4Ó«å¼]"j»"éכÚý9ÐÈ}ƒÀŒ½|Ùl“â5’ïZ“êáKÊ¿ Dn¡r ±Ú—JÃ…ÝÆïËr&%šaìFÿ\ÎøÉžN'|PrÓ‚4²CÞP«ƒ÷Þ¡ÀI_”«)QG†©÷ ¾öfŽH¢¥¤× ñ‚Wtl«£â6CD†]Á{ÃZ–b:w¤Øm2BuRý:\a gë&­ÚݰÜF ì2çä ˆˆz ûx<&3¹„j¤1 ·²&Di=˜ºÅý5pXwo£)9”Œ±„ü ZRåæ–ú¦‡#-x—«Ž,n{d# xUNƒ %Ñ 0(×w@ÿ4? S fb ad .x ¦ C¬ dýï dÄì hs° Æ####réd+[[[[[[[[[[ B†† D3£££££££££££ i5ÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖÖ 0L    0DW D+›››››››››› AYÆÆ 0Få˜HP LaserJet Series IIHPPCL,È,,,,,È0nL>Î(ÖÃ9 Z ‹6Times New Roman RegularX($¡¡ æ ç Eè é ê Eë ì Eí î Dï ¶N¡"3|)ï ÔTABLE A $CZCS~pigment~=~1.34€CDOT€Chla^{0.98}H 9X~=~log_{10}LEFT({R_{rs}(490)}€OVER€{R_{rs}(555)}€RIGHT).XX\XXXè\äXX¸\log¸ô10XX>&hXX>äjXX>¢jXX>`jXX>jXX>ÜjXX>iXX&oXXäqXX¢qXX`qXXqXXÜqXXpœX½ˆXXÕFROÞrsXX·F(XXúF490XX&F)XXÕÄRO\rsXX·Ä(XXúÄ555XX&Ä)XXø\.XXnCZCSXXKnpigmentXX(näXXøn1XX\n.XXŽn34XXVnXXˆnChla- à0p à.‘ à98ð?ÐTABLE ALevel 1Level 2Level 3Level 4Level 5 hChla~=~„0.040`+`10€SUP€{€(0.341`„`3.001€`CDOT`€X`+`2.811€`CDOT`€X€^2€`„`2.041€`CDOT`€X^3)ññ€}€ññÌÌXXnChlaXXÝnäXX­nãXX%n0XX‰n.XX»n040XXýnâXX‹n10Sà(à0Âà.ãà341ºàãà3[à.|à001S àƒ àXâ àâ@ à2ƒ à.¤ à811{ à« àX,, :2Q à㯠à2ò à. à041ê ààX,,€:3²à) d'ÿÿdxd!-øÿ%>c$"Small Circleð"ðà0 à(3¯$££Ý ƒ!ÝÝ  Ý'ÈÈÈÈdxdbVcWMüÿ << deUU…Level 1Level 2Level 3Level 4Level 5(n$––ò ò(Ú  Ú1Ú  Ú)ó óÝ ƒ!ÝÝ  ÝÑ  ÑÑ7€8²XXdédÈ7Ñà@AAìàÔ‡¼5ƒ¼XXÔò òSeaWiFS€Bio„optical€Algorithm€Mini„workshop€(SeaBAM)€Overviewó óÔ#†X8²X¼¼5ƒq#ԈР° ÐÌà@ˆˆ5ìàbyˆÌÌà@””0ìàC.€R.€McClainˆÌà@  &ìàNASA€Goddard€Space€Flight€CenterˆÌà@¡¡-ìàGreenbelt,€MarylandˆÌÌà@ÍÍ2ìàò òABSTRACTó óˆÐ  i ÐÌOne€of€the€primary€goals€of€the€SeaWiFS€Project€is€to€routinely€generate€global€chlorophyll„aÏand€CZCS€pigment€concentrations€with€an€accuracy€of€ðð35%.€€Since€its€inception€in€1991,Ïthe€SeaWiFS€Calibration€and€Validation€Program€has€undertaken€a€number€of€initiatives€toÏhelp€ensure€that€this€goal€is€met,€e.g.€measurement€protocol€development,€calibration€roundÏrobins,€the€bio„optical€data€archive€and€bio„optical€algorithm€workshops.€€After€the€seventhÏbio„optical€algorithm€workshop€held€in€Halifax,€Nova€Scotia€on€October€21,€1996,€it€wasÏclear€that€algorithm€and€data€quality€issues€remained€that€could€not€be€adequately€addressedÏin€the€standard€workshop€format.€€A€more€interactive€analysis€(data€sets€and€algorithms)Ïoriented€workshop€was€deemed€necessary€in€order€to€focus€on€specific€problems.€€As€a€result,Ïthe€first€SeaWiFS€Bio„optical€Algorithm€Mini„workshop€(SeaBAM)€was€hosted€by€D.€SiegelÏat€UC/Santa€Barbara€during€January€21„24,€1997.€€This€chapter€provides€an€overview€of€theÏworkshop€background,€organization,€approach€and€results€from€the€workshop€and€otherÏassociated€activities.ÌÌò òINTRODUCTIONó óÐ ©ù Ðà  àEarly€in€the€definition€of€the€SeaWiFS€program,€the€ocean€color€science€communityÏestablished€a€mission€goal€of€estimating€global€surface€chlorophyll„a€and€CZCS€pigmentÏconcentrations€to€within€ðð35%€(Hooker€et€al.,€1992).€€The€rationale€behind€the€CZCS€pigmentÏproduct€(chlorophyll„a€plus€phaeophytin)€is€to€provide€a€data€set€that€can€be€compared€toÏproducts€derived€from€the€CZCS€for€studies€of€decadal€scale€variability.€€Early€comparisonsÏof€in€situ€and€CZCS€global€products€(Balch€et€al.,€1992)€indicated€that€this€goal€was€feasibleÏfor€most€of€the€global€ocean.€€Subsequent€studies,€however,€noted€significant€differences€evenÏin€clear€water€environments€(Arrigo€et€al.,€1994).€€The€CZCS€algorithm€was€based€on€55€bio„¼optical€stations€in€coastal€U.S.€waters€(Clark,€1981;€usually€referred€to€as€the€NimbusÏExperiment€Team€or€NET€data€set)€and€even€by€1991,€that€data€set€was€the€only€data€setÏgenerally€available€for€algorithm€development.€€As€a€result,€the€SeaWiFS€Calibration€andÏValidation€(Cal/Val)€Program€initiated€several€activities€directed€at€improving€the€quality€bio„¼optical€data€collected€by€the€ocean€optics€community.€€These€activities€include€theÏestablishment€of€measurement€protocols€(Mueller€and€Austin,€1992€and€1995),€a€calibrationÏround€robin€(e.g.€Johnson€et€al.,€1996),€the€SeaWiFS€Bio„optical€Archive€and€Storage€SystemÏ(SeaBASS;€Hooker€et€al.,€1994),€the€SeaWiFS€Transfer€Radiometer€(SXR)€and€the€SeaWiFSÏQuality€Monitor€(SQM;€Shaw€et€al.,€1996).€€In€addition,€seven€bio„optical€algorithmÏworkshops€have€been€held,€brief€proceedings€of€which€are€published€in€the€SeaWiFSÏTechnical€Memorandum€cumulative€index€issues€(see€Volumes€12,€18,€24€and€36).Ìà  àThe€bio„optical€algorithm€workshops€have€been€open€events€and€have€provided€aÏforum€for€presentation€and€detailed€(often€quite€frank)€discussions€on€protocols,€dataÐ Æ-)-ó Ðcollection€and€algorithm€issues.€€Early€in€the€deliberations€on€algorithm€development,€it€wasÏdecided€to€avoid€switching€algorithms€such€as€was€used€in€the€global€CZCS€reprocessingÏ(Gordon€et€al.,€1983)€and€to€use€a€semi„analytical€chlorophyll€algorithm.€€SwitchingÏalgorithms€tend€to€produce€bimodal€frequency€distributions€as€an€artifact€of€the€switchingÏlogic€(Denman€and€Abbott,€1988;€Muller„ñï ñ¼ñï ñKarger€et€al.,€1990).€€Semi„analytical€algorithmsÏ(Carder€et€al.,€1991;€Garver€and€Siegel,€1995;€Carder€et€al.,€1996)€would€allow€more€physicalÏinsight€into€the€optical€processes€that€determine€oceanic€reflectance€thus€providing€aÏmechanism€for€incorporating€strategies€to€account€for€regional€and€temporal€variability€in€theÏalgorithm.€€The€discussions€at€the€workshops€have€been€very€constructive€in€highlightingÏdifferences€in€perceptions€and€approaches€to€algorithm€development.€€For€example,€the€CZCSÏpigment€product€raised€several€questions.€€Should€the€algorithm€be€chlorophyll„a€orÏchlorophyll„a€+€phaeophytin€as€it€was€just€as€easy€to€develop€an€empirical€algorithm€forÏchlorophyll„a€(Aiken€et€al.,€1995).€€If€just€chlorophyll„a,€why€is€a€CZCS€pigment€productÏneeded?€€Should€the€CZCS€pigment€product€be€based€only€on€CZCS€bands€(SeaWiFSÏequivalents)€and€should€be€product€be€derived€using€a€CZCS€atmospheric€correction?€€TheÏissue€is€that€if€the€CZCS€atmospheric€correction€scheme€(uses€670€nm)€and€bio„optical€bandÏlimitations€(443,€520€and€550€nm)€introduce€a€systematic€bias€in€the€pigment€product€that€isÏnot€reproduced€in€subsequent€ocean€color€data€sets,€the€interpretation€of€decadal€scale€changeÏwill€be€compromised..€Another€question€is€what€measurements€of€pigments€should€be€used€inÏdefining€the€CZCS€pigment€product€given€the€evolution€in€measurement€techniquesÏ(fluorometric,€HPLC,€etc.)€and€is€consistency€with€the€original€NET€CZCS€data€set€necessary?€ÏIn€the€end,€the€general€concensus,€though€not€unanimous,€was€to€continue€use€the€originalÏproduct€definition,€but€to€use€the€best€algorithms€possible,€i.e.€the€SeaWiFS€atmosphericÏcorrection€and€no€restriction€on€the€bands€to€be€used€for€the€bio„optical€algorithms.ÌÔ% € Ôà  àWith€regard€to€the€SeaWiFS€Science€Working€Group€bio„optics€subgroupððsÏrecommendation€to€pursue€semi„analytical€algorithms€for€operational€use,€it€has€become€clearÏthat€the€existing€semi„analytical€algorithms€are€limited€to€Case€I,€relatively€low€pigmentÏwaters.€€The€main€issues€are€a€paucity€of€data€on€scattering€and€the€variability€in€spectralÏabsorption.€€While€new€methods€and€instrumentation€for€measuring€the€backscatteringÏcoefficient€hold€promise,€little€is€currently€available.€€Also,€the€measurement€of€spectralÏabsorption,€let€alone€a€way€of€parameterizing€its€variability,€remains€an€issue.€€In€response€toÏthis€problem,€the€SeaWiFS€Cal/Val€program€funded€a€workshop€at€Scripps€Institute€ofÏOceanography,€hosted€by€G.€Mitchell€and€A.€Bricaud,€in€December€1996€to€compare€andÏevaluate€different€methods.€€The€results€of€the€workshop€are€not€available€as€yet.€€Thus,€at€theÏpresent€time,€the€semi„analytical€algorithms€are€inherently€empirical,€at€a€different€level,€andÏsome€resort€to€strictly€empirical€relationships€at€high€concentrations€(Carder€et€al.,€1996).€ÏThe€limitations,€at€the€present€time,€reside€in€the€determination€of€the€various€absorption€andÏbackscattering€coefficients,€i.e.,€measurement€methodologies,€parameterizations,€etc.€€DespiteÏthese€limitations,€semi„analytical€algorithms€do€generate€reasonable€chlorophyll„a€values€forÏmost€of€the€global€ocean€as€well€as€a€number€of€other€quantities€that€could€be€routinelyÏproduced€by€the€SeaWiFS€Project,€if€required€by€the€science€community.€€Also,€they€can€beÏeasily€adapted€to€any€combination€of€wavelengths€commensurate€with€any€satellite€sensor.€ÏTherefore,€whether€or€not€the€initial€SeaWiFS€algorithms€are€semi„ñï ñ¼ñï ñanalytical,€theirÏdevelopment€should€continue€because€the€original€rationale€remains€valid€and€justified.Ð Ó+#'+ Ðà  àFinally,€another€issue€which€complicates€the€algorithm€evaluation€process€stems€fromÏdifferences€in€reflectance€measurement€methodologies,€i.e.€above„surface€vs.€below„surface.€ÏBoth€methods€have€limitations.€€Above„surface€measurements€are€contaminated€by€sky„light,Ïglint,€polarization€and€plaque€bidirectional€reflectance€effects.€€Below„surface€measurmentsÏrequire€absolute€radiance€calibrations,€an€extrapolation€through€the€air„sea€interface€and€aÏcorrection€for€instrument€self€shading€in€turbid€water.€€The€Carder€et€al.€(1996)€algorithmÏutilizes€above„surface€measurements,€but€the€bulk€of€the€data€available€for€independentÏalgorithm€verification€are€below„ñï ñ¼ñï ñsurface€observations.€€No€systematic€comparison€of€the€twoÏmethods€has€been€conducted€and€published€and€the€protocol€for€making€above„surfaceÏreflectance€measurements€(Mueller€and€Austin,€1995)€is€considered€by€many€to€be€inadequate.€ÏThe€SeaWiFS€Project€sponsored€a€workshop€on€Case€II€measurement€protocols€in€the€springÏof€1996€(see€Vol.€36)€with€the€objective€of€refining€the€existing€protocols,€but€the€workshopÏcoordinators€have€not€completed€the€document€that€was€outlined€at€the€meeting.€€TheÏSIMBIOS€Project€plans€to€sponsor€focused€field€experiments€designed€to€clarify,€andÏhopefully,€resolve€this€issue.Ìà  àAfter€the€seventh€bio„optical€algorithm€meeting€in€October€1996,€it€was€clear€thatÏconvergence€on€the€operational€algorithms€was€not€happening€in€a€satisfactory€manner.€ÏIndeed,€the€primary€candidate€algorithms€for€chlorophyll„a€(Carder€et€al.,€1996)€and€CZCSÏpigment€(Aiken€et€al.,€1995)€were€seriously€inconsistent€at€moderate€and€high€concentrations,Ïi.e.€chlorophyll„a€>>€CZCS€pigment.€€It€is€with€all€the€above„mentioned€considerations€inÏmind€that€SeaBAM€was€initiated.€€The€consensus€was€that€further€progress€would€result€onlyÏif€the€participants€work€collectively€with€open€access€to€data€and€code€(data€processing€andÏalgorithm)€in€a€similar€fashion€to€the€data€analysis€round€robin€held€at€UC/SB€in€1994€(SiegelÏet€al.,€1995).€€The€following€sections€outline€the€workshop€strategy€including€pre„€and€post„¼workshop€activities€and€a€summary€of€the€findings€derived€as€a€result€of€the€SeaBAMÏprocess.€€It€is€the€philosophy€of€the€SeaWiFS€Project€not€to€develop€the€operationalÏalgorithms,€but€to€expedite€algorithm€development€via€whatever€mechanisms€are€possible€andÏto€provide€an€independent€and€objective€evaluation.€€From€the€SeaWiFS€Projectððs€perspective,ÏSeaBAM€has€achieved€more€than€was€initially€hoped€for€because€of€the€enthusiasm€andÏopenness€of€all€the€participants.€€Data€and€software€were€freely€exchanged,€errors€wereÏrevealed€and€corrected€(without€angst),€and€substantial€improvements€in€almost€all€theÏevaluated€algorithms€have€been€made.€€Last,€but€not€least,€a€consistent€set€of€chlorophyll„aÏand€CZCS€pigment€algorithms€have€been€identified€using€a€large€bio„optical€data€setÏrepresenting€a€diversity€of€bio„optical€provinces.ÌÌò òOBJECTIVES€AND€APPROACHó óÐ ‹$Û# Ðà  àGiven€that€the€primary€objective€was€to€finalize€and€deliver€the€operational€SeaWiFSÏchlorophyll„a€and€CZCS€pigment€algorithms€in€a€relatively€short€time,€it€was€agreed€by€theÏparticipants€(listed€below)€that€a€successful€workshop€would€require€a€substantial€amount€ofÏpre„ñï ñ¼ñï ñworkshop€preparation€and€the€free€and€rapid€dissemination€of€data,€code€and€results.€€ItÏalso€required€that€all€involved€be€willing€to€assist€one€another,€work€out€problems€andÏdifferences€of€opinion€internally€and€that€recognize€that€all€options€were€open€with€regard€toÏthe€final€algorithm€selections.€€The€strategy€was€to€have€a€balanced,€but€small,€group€ofÏparticipants€including€representatives€from€the€SeaWiFS€Project€and€others€who€had€beenÐ Ó+#'+ Ðactive€in€the€bio„optics€subgroup€as€algorithm€developers€(empirical€and€semi„analytic)€andÏbio„optical€data€providers€(Table€1).€€It€was€also€agreed€that€D.€Siegel€would€host€theÏworkshop€at€UC/SB€and€that€he€would€assume€responsibility€for€providing€a€workshopÏenvironment€that€efficiently€accommodated€both€group€discussion€and€presentation€sessionsÏand€a€heterogenous€computing€and€data€storage€environment.€€GSFC€would€coordinate€pre„Ïand€post„workshop€activities€including€maintenance€of€an€access„restricted€SeaBAM€web€pageÏwhere€data,€results€and€email€would€be€posted€and€archived.€€Both€S.€Maritorena€(GSFC)€andÏS.€Garver€(UC/SB)€had€been€developing€data€sets€of€water„leaving€radiances€(and€otherÏrelated€quantities)€with€associated€pigment€data€for€the€purposes€of€independent€evaluationÏand€algorithm€development,€respectively€(Maritorena€et€al.,€and€Garver€and€Siegel,€thisÏvolume).€€They€would€continue€the€refinement€and€expansion€of€these€data€sets,€coordinateÏtheir€activities,€e.g.,€exchange€data,€in€preparation€for€the€miniworkshop€and€provide€the€dataÏsets€to€the€other€participants.€€The€initial€version€of€the€Maritorena€et€al.€data€set€which€wasÏpresented€at€the€Halifax€workshop€consisted€of€approximately€90„100€clear„sky€stations.€€ItÏwas€agreed€that€this€condition€was€too€restrictive€and€that€other€data€should€be€incorporated.€ÏFinally,€it€was€agreed€that€all€groups€would€provide€documentation€on€their€evaluations€andÏresults€to€be€combined€into€a€SeaWiFS€TM.ÌÌÔ*ƒ ,ddd Xdd Xdd X°(#°(#ÔÔ,Ä dd ÔÔ,dd ÔÔ+  ÔÐ  b €€……ÐTable€1.€€SeaBAM€ParticipantsÐ vÆ   ÐÓ  ÓIndividualsÐ óC  ÐÓ+3ÓÓ  ÓInstitutionñï ñ¹ñï ñ¹Ón3ÓÐ  Ü, ÐDave€Siegel€&€Sara€GarverÐ  Y© ÐUniversity€of€California/Santa€BarbaraÐ  Y© ÐGreg€Mitchell€&€Mati€KahruÐ  Ö& ÐScripps€Institute€of€OceanographyÐ  Ö& ÐGerald€MooreÐ  S£ ÐPlymouth€Marine€LaboratoryÐ  S£ ÐJim€MuellerÐ  Ð  ÐSan€Diego€State€UniversityÐ  Ð  ÐJohn€OððReillyÐ  M ÐNational€Marine€Fisheries€ServiceÐ  M  ÐKen€Carder€&€Steve€HawesÐ  Ê ! ÐUniversity€of€South€FloridaÐ  Ê " ÐChuck€McClain,€Stephane€Maritorena€&ÏBrian€SchieberÐ  0#€$ ÐSeaWiFS€Project,€NASA€Goddard€SpaceÏFlight€CenterÐ 0#€&  ÐÌà  àTo€establish€a€framework€for€SeaBAM,€an€initial€set€of€issues,€tasks€and€goals€wereÏoutlined€which€included€the€following:ÌÌà8  à(a)€Settle€on€the€definition€of€€ð ðCZCS€pigmentsðð.€€This€question€is€the€result€ofÏthe€differences€in€measurement€methodologies.Ð Ð Ð  ÐÌà8  à(b)€Establish€a€clear€definition€of€accuracy€and€identify€the€appropriateÏstatistical€parameter(s)€for€quantification€of€accuracy€as€it€applies€to€algorithms.Б+á&.Ð Ð  Їà8  à(c)€Establish€criteria€for€final€selection€of€the€ð ðbestðð€algorithm€for€both€pigmentÏparameters.Ð Ð Ð  ÐÌà  à(d)€Identify€the€algorithms€to€be€compared€and€identify€probable€reasons€forÏdifferences.€Ìà  àUltimately,€the€algorithms€included€the€following:Ìà  àà ` àAiken€et€al.€(1995)Ìà  àà ` àCarder€et€al.€(1996)Ìà  àà ` àClark€(1996)Ìà  àà ` àGarver€&€Siegel€(1995)Ìà  àà ` àMitchell€&€Kahru€(CalCOFI;€unpublished)Ìà  àà ` àMorel€(1996)Ìà  àà ` àNew€empirical€(e.g.€one€based€on€the€evaluation€data€set)Ìà  àà ` àGordon€et€al.€(1983)Ìà  àà ` àOCTS€operational€chlorophyll„aÌà  àà ` àPOLDER€operational€algorithmÌÌà  à(e)€Establish€data€set€selection€guidelines.€€Considerations€included:Ìà  àà ` àBlending€of€HPLC€pigments€with€fluorometric€pigmentsÌà  àà ` àSeaWiFS€measurement€protocols€complianceÌà  àà ` àBlending€of€in„water€and€above„water€estimates€of€Ròòrsóó€or€LòòWNóóÐ ä4 Ðà  àà ` àConsistency€in€analyses€used€to€derive€LòòWóó€from€in„water€measurementsÐ Í Ðà  àà ` àÌà8  à(f)€Select€the€data€sets€to€be€used€for€the€comparisons.€€The€individual€data€setsÏwere:Ð Ð Ð  Ðà  àà ` àCarder€et€al.€(above„water€observations)Ìà  àà ` àGarver€&€Siegel€(in„water€observations)Ìà  àà ` àMaritorena€et€al.€evaluation€data€set€(in„water€observations)Ìà  àà ` àMitchell€&€Kahru€(CalCOFI,€in„water€observations)ÌÌAll€issues€were€eventually€addressed.€€Several€items€are€discussed€in€detail€in€other€chaptersÏof€this€TM.ÌÌò òThe€UC/SB€MEETINGó óà  àÐ ¹" ! Ðà  àPrior€to€the€workshop,€a€global€evaluation€data€set€was€assembled€by€combining€aÏnumber€of€data€sets€contributed,€primarily,€by€the€participants.€€€J.€OððReilly€and€S.€MaritorenaÏused€this€data€set€to€complete€an€initial€comparison€of€all€algorithms€prior€to€the€meeting.€ÏThe€first€day€of€the€meeting€consisted€of€briefings€by€all€groups€to€provide€updates€on€allÏpreparations€and€results€stemming€from€pre„workshop€activities.€€During€the€presentations,€anÏissues€and€analysis€action€item€list€was€developed€and€reviewed€at€the€end€of€the€session.€ÏThereafter,€the€groups€conducted€hands„on€analyses€to€address€the€action€items€andÏperiodically€reconvened€to€report€progress€and€register€any€additional€issues€that€needed€to€beÏtracked.€€On€the€last€day,€a€plenary€was€held€to€review€the€final€status€of€all€action€items€andÏto€outline€the€post„workshop€activities€and€schedule.€€To€provide€some€insight€into€what€theÐ Ó+#'+ Ðaction€items€were€and€how€they€were€resolved,€several€are€described€in€the€appendix..ÌÌò òÔ& Ò ÔFINAL€RESULTS€AND€CONCLUSIONSó óÐ ‚Ò Ðà  àAs€discussed€above,€all€the€original€issues€have€been€addressed€as€well€as€a€number€ofÔ'Ò‚ÑCÔÏothers€that€developed€during€SeaBAM.€€Conducting€algorithm€development€in€this€fashionÏgreatly€expedited€resolution€of€many€questions.€Most€of€the€algorithms€and€the€evaluationÏdata€set€have€been€improved€as€a€result€of€SeaBAM€as€discussed€in€detail€in€other€chapters€ofÏthis€TM.€€The€most€important€results€are€the€final€recommendations€on€the€operationalÏSeaWiFS€algorithms€which€are€summarized€below.ÌÌ1.€€òòChlorophyll„aóó.€€Because€the€evaluation€data€set€has€the€most€bio„optical€diversity€of€theÐ Ê   Ðdata€sets€listed€above€and€was€quality€controlled€and€processed€in€a€consistent€mannerÏ(Maritorena€et€al.,€this€volume),€it€was€used€to€obtain€the€ð ðbestðð€algorithm€possible.€ÏTherefore,€it€evolved€from€being€an€independent€data€set€to€one€used€to€develop€empiricalÏalgorithms€as€well.€€Not€only€were€all€final€versions€of€the€algorithms€as€submitted€by€theÏdevelopers€considered,€but€also,€for€the€empirical€algorithms,€€these€and€other€algorithmicÏforms€(band€ratio€combinations)€were€fit€to€the€evaluation€data€to€see€what€improvementsÏwere€possible.€€The€algorithm€that€gave€the€best€overall€result€based€on€the€selection€criteriaÏoutlined€in€OððReilly€and€Maritorena€(this€volume)€uses€only€a€ratio€of€490€nm€to€555€nm,€i.e.,ÌÌß>€a-` 0  `€>ßâ °±°±°(#°(#â°â °±°±°±°±â°â °±°±°±°±â°â °±°±°±°±â°â °(#°(#°±°±âwhereÌßc€a -` 0  `€E°ûx=œ d@uèø cßâ °±°±°(#°(#â°â °±°±°±°±â°â °±°±°±°±â°â °±°±°±°±â°â °±°±°±°±â°â °±°±°±°±â°â °(#°(#°±°±âThis€result€is€consistent€with€the€Aiken€et€al.€(1995)€finding€that€a€490:555€band€ratio€yieldedÏthe€highest€correlation€(ròò2óó€=€0.95)€for€the€data€sets€in€their€analysis.Ð Ñ!!  ÐÌ2.€òòCZCS€pigmentóó.€As€discussed€in€OððReilly€and€Maritorena€(this€volume),€there€are€a€numberÐ £#ó" Ðof€options€for€this€product,€not€all€of€which€follow€the€original€guideline€of€using€anÏalgorithm€that€utilizes€only€the€CZCS€bands.€€Clearly,€there€should€be€reasonable€consistencyÏbetween€the€two€pigment€products.€€Also,€an€evaluation€data€set€for€the€CZCS€comparable€toÏthe€one€just€completed€for€SeaWiFS€needs€to€be€generated.€€For€the€at„launch€algorithm,€theÏrecommendation€is€the€following€relationship€which€is€based€on€a€empirical€relationshipÏchlorophyll„a€and€chlorophyll„a€+€phaeophytin€concentrations€derived€from€the€SeaBASSÏpigment€data€base,€i.e.,Ìßc€a -` 0  `€E°Ï&xç# d2 èÌ& ²cßâ °±°±°(#°(#â°â °±°±°±°±âÐ Õ+%'+°±°± Ðà  àIt€is€important€to€note€that€the€SeaWiFS€Project€plans€to€periodically€reprocess€theÏentire€SeaWiFS€data€set€as€algorithms€(atmospheric,€bio„optical,€mask€and€flag),€sensorÏcalibration€and€product€suites€are€updated.€€Thus,€it€is€critical€that€the€SeaBAM€activity€beÏcontinued.ÌÌÔ&  Ôò òAPPENDIX:€Workshop€Action€Itemsó óÐ =  ÐÌà  àIn€order€to€emphasize€the€benefits€of€conducting€workshops€that€are€oriented€aroundÏdata€analysis€and€real€time€algorithm€evaluation,€the€following€list€of€results€stemming€fromÏaction€items€are€provided€below.€€This€meeting€format€expedited,€even€forced,€the€resolutionÏof€questions€and€issues,€usually€at€the€meeting.€€In€the€typical€meeting€format,€questions€oftenÏgo€unresolved€resulting€in€continued€debate€and€misunderstanding.ÌÌ1.€State€succinctly€the€practical€definitions€of€CZCS€pigments€and€chlorophyll„a€with€rationaleÏfor€the€choices.Ô' = »PÔÌÌà8  àòòCZCS€pigmentóó:€òòA€fluorometric€pigment€concentration€(chlorophyll„a€+Ð @ Ðphaeopigments)€that€can€be€calculated€using€bands€comparable€to€the€CZCSÏwavelengths€(443,€520,€550).óó€€Note€that€the€SeaWiFS€protocols€need€to€beÐ c Ðmore€detailed€on€this€topic.€€The€purpose€of€generating€this€product€is€toÏprovide€a€means€of€comparing€products€that€can€be€derived€from€the€CZCS€toÏthose€from€later€missions€for€examining€decadal€scale€variability.€€RestrictingÏthe€algorithm€to€the€CZCS€wavelengths€minimizes€biases€introduced€in€theÏproducts€that€are€artifacts€of€the€algorithm€form.€€It€is€assumed€that€the€globalÏCZCS€data€set€will€be€reprocessed€using€an€updated€pigment€algorithm€that€isÏconsistent€with€the€SeaWiFS€pigment€algorithm.€€S.€Maritorena€will€evaluateÏthe€assumption€that€the€differences€between€fluormetric€and€HPLC€bio„opticalÏdata€sets€are€indistinquishable€using€the€evaluation€data€set.Ð Ð Ð  Ðà8  àà ` àThe€issue€of€how€to€validate€the€reprocessed€CZCS€products€usingÏsimultaneous€measurements€was€discussed.€€Given€that€algorithms€beingÏdeveloped€at€this€time€are€based€on€different€pigment€measurementÏmethodologies€which€yield€different€values,€validation€using€historical€data€willÏrequire€some€adjustment€in€the€historical€values.€€Ð Ð Ð  Ðà8  àà ` àStatus:€Post„workshop€examination€of€the€SeaBASS€data€sets€showedÏthat€there€are€a€very€limited€number€of€stations€available€having€the€CZCSÏbands€and€chlorophyll„a€+€phaeophytin€concentrations€on€which€to€base€aÏð ðglobalðð€algorithm€(Maritorena€et€al.,€this€volume)€and€alternative€strategies€areÏoutlined€in€OððReilly€and€Maritorena€(this€volume).Ð Ð Ð  ÐÌà8  àòòChlorophyll„aóó:€òòAny€fluorometric€or€HPLC€concentration€identified€asÐ 0(€#' Ðchlorophyll„a€by€the€provider.óó€€While€there€are€differences€in€the€valuesÐ )j$( Ðobtained€by€the€two€techniques,€globally€the€difference€has€been€shown€to€beÏof€the€order€of€10%€(analyses€by€C.€Trees).€€Also,€at€least€for€the€time€being,Ïboth€HPLC€and€fluorometric€data€have€been€combined€in€order€to€have€a€dataÐ Õ+%'+ Ðset€sufficiently€large€with€enough€diversity€to€cover€the€broad€range€ofÏchlorophyll€concentrations€required€for€development€of€a€general€chlorophyllÏalgorithm.€Debate€continues€as€to€what€pigments€should€or€are€being€summedÏand€reported€as€ð ðchlorophyllðð€concentration€in€the€data€sets€being€submitted€toÏSeaBASS.€€Ð Ð Ð  Ðà8  àà ` àStatus:€Because€other€sources€of€variability€in€the€bio„optical€data€sets,Ïe.g.€data€processing€methods€and€calibration€have€been€found€to€be€as€great,Ïand€in€order€to€have€enough€data€over€a€large€dynamic€range€to€develop€andÏevaluate€algorithms,€this€definition€was€adopted.Ð Ð Ð  ÐÌ2.€Reconcile€the€differences€in€the€CalCOFI„2€Lòòwóó€spectral€shapes€as€obtained€independentlyÐ Ê   Ðby€S.€Garver€and€M.€Kahru.€€The€problem€is€an€elevated€shoulder€at€490nm€relative€to€443Ïnm€in€the€Kahru€analysis.Ìà8  àStatus:€The€anomalous€spectral€shoulder€was€found€to€be€a€typographical€errorÏin€a€table€used€in€the€transformation€of€subsurface€Lu(443)€to€the€above„surfaceÏLòòwóó(443).ÐW§ Ð Ð  ÐÌ3.€Resolve€a€problem€S.€Garver€and€D.€Siegel€observe€with€some€of€C.€Treeððs€NABE€(NorthÏAtlantic€Bloom€Experiment)€optical€data.€Ìà8  àStatus:€J.€Mueller€checked€the€scaling€factor€Garver€and€Siegel€were€using€andÏthe€problem€was€a€misinterpretation€of€the€scaling€factor€format.€€NABE€isÏconsistent€with€other€data€sets.Ð Ð Ð  ÐÌ4.€€Determine€the€reason€by€the€412€nm€surface€reference€values€in€G.€Cotaððs€Resolute€BayÏdata€are€inconsistent€with€values€in€the€profile€data€(a€2„4€fold€difference€was€found€in€allÏprofiles€for€all€three€cruises,€each€in€a€different€year).Ìà8  àStatus:€G.€Cota€was€contacted€and€will€try€to€develop€a€time€series€of€hisÏcalibration€data.€The€412€nm€filters€were€replaced€in€both€instruments€after€theÏ1995€field€campaign.€As€a€result,€the€1994€and€1995€data€were€excluded€fromÏthe€evaluation€data€set,€but€the€1996€data€were€retained.Ð Ð Ð  ÐÌ5.€€Verify€a€constant€offset€between€the€evaluation€data€set€and€D.€Clarkððs€algorithm€(theÏalgorithm€had€the€highest€ròò2óó€when€compared€with€the€evaluation€data€set).Ð Ð!   Ðà8  àStatus:€J.€Mueller€and€S.€Maritorena€spoke€with€D.€Clark€after€the€workshop.€ÏThe€source€of€the€offset€could€not€be€readily€identified,€so€further€evaluation€ofÏthe€Clark€algorithm€was€deferred€until€an€update€is€made€available.Ð Ð Ð  ÐÌ6.€Examine€the€impact€of€data€with€565€nm€rather€than€555€nm€on€the€algorithm€comparisons.ÏThe€WOCE€and€early€BATS€data€have€565€nm€measurements€rather€than€555€nm.€€Both€dataÏsets€are€from€low€pigment€waters.€€Given€the€significant€slope€in€water€absorption€spectrumÏat€these€wavelengths,€the€data€should€be€corrected€or€omitted€from€the€SeaWiFS€algorithmÏevaluations.€Ìà8  àStatus:€S.€Maritorena€analyzed€several€data€sets€and€derived€a€correction€factorÏfor€transforming€565€nm€to€555€nm€radiances.€Tthe€corrected€data€wereÐ Ó+#'+ Ðretained€in€the€evaluation€data€set.аРР ÐÌ7.€€Investigate€what€appears€to€be€anomalous€412€nm€data€in€J.€Marraððs€WOCE€data€set.€ÏSome€412€nm€data€appears€to€be€very€high€even€for€very€clear€water.Ìà8  àStatus:€J.€Mueller€did€the€calibration€on€J.€Marraððs€MER€and€followed€up€onÏthis€question.€€As€a€result,€the€1991€data€was€removed€from€the€evaluation€dataÏset€because€of€concerns€about€the€calibration,€but€the€data€from€1993€and€1994Ïwere€retained.Ð Ð Ð  ÐÌÌò òREFERENCESó óÐ Ê   ÐÌAiken,€J.,€G.F.€Moore,€C.C.€Trees,€S.B.€Hooker€and€D.K.€Clark,€1995:€The€SeaWiFS€CZCS„¼Type€Pigment€Algorithm.€NASA€Tech.€Memo.€104566,€Vol.€29,€S.B.€Hooker€and€E.R.ÏFirestone,€Eds.,€NASA€Goddard€Space€Flight€Center,€Greenbelt,€Maryland,€43€pp.ÌÌArrigo,€K.R.,€C.R.€McClain,€J.K.€Firestone,€C.W.€Sullivan€and€J.C.€Comiso,€1994:ÏComparison€of€CZCS€and€in€situ€pigment€concentrations€in€the€Southern€Ocean,€In€CaseÏStudies€for€SeaWiFS€Calibration€and€Validation,€Part€1.€NASA€Tech.€Memo.€14566,€Vol.€13,ÏS.€B.€Hooker€and€E.R.€Firestone,€Eds.,€NASA€Goddard€Space€Flight€Center,€Greenbelt,ÏMaryland,€30„34.ÌÌBalch,€W.M.,€R.€Evans,€J.€Brown,€G.€Feldman,€C.€McClain,€and€W.€Esaias,€The€remoteÏsensing€of€ocean€primary€productivity„„use€of€a€new€data€compilation€to€test€satelliteÏalgorithms,€òòJ.€Geophys.€Res.óó,€òò97óó:C2,€2279„2293,€1992.Ð ˆØ ÐÌCarder,€K.L.,€S.K.€Hawes,€K.A.€Baker,€R.C.€Smith,€R.G.€Stewart€and€B.G.€Mitchell,ÏReflectance€model€for€quantifying€chlorophyll€òòaóó€in€the€presence€of€productivity€degradationÐ C“ Ðproducts,€òòJ.€Geophys.€Res.óó,€òò96óó(C11),€20,599„20,611,€1991.Ð -} ÐÌCarder,€K.L.,€S.K.€Hawes€and€Z.€Lee,€SeaWiFS€algorithm€for€chlorophyll„a€and€coloredÏdissolved€organic€matter€in€subtropical€environments,€submitted€to€òòJ.€Geophys.€Res.óó,€1996.Ð è 8 ÐÌClark,€D.€K.,€Phytoplankton€pigment€algorithms€for€the€Nimbus„7€CZCS,€in€òòOceanographyÐ º" ! Ðfrom€Spaceóó,€edited€by€J.€R.€F.€Gower,€Plenum€Press,€New€York,€227„237,€1981.Ð £#ó" ÐÌClark,€D.K.,€MODIS€Algorithm€Theoretical€Basis€Document,€Bio„optical€Algorithms„Case€1ÏWaters,€22€pp.,€1996.ÌÌDenman,€K.€L.€and€M.€R.€Abbott,€Time€evolution€of€surface€chlorophyll€patterns€from€crossÏspectrum€analysis€of€satellite€color€images,€òòJ.€Geophys.€Res.óó,€òò93óó(C6),€6789„6798,€1988.Ð )i$( ÐÌ‚Gordon,€H.€R.,€D.€K.€Clark,€J.€W.€Brown,€O.€B.€Brown,€R.€H.€Evans€and€W.€W.€Broenkow,ÏPhytoplankton€pigment€concentrations€in€the€Middle€Atlantic€Bight:€€Comparison€of€shipÐ Ô+$'+ Ðdetermina‚tions€and€CZCS€estimates,€òòAppl.€Opt.óó,€òò22óó(1),€20„36,€1983.Ð ° ÐÌGarver,€S.A.€and€D.A.€Siegel,€Inherent€optical€property€inversion€of€ocean€color€spectra€andÏits€biogeochemical€interpretation:€1.€Time€series€from€the€Sargasso€Sea,€submitted€to€òòJ.Ð k» ÐGeophys.€Res.óó,€1995.Ð T¤ ÐÌHooker,€S.B.,€W.E.€Esaias,€G.C.€Feldman,€W.W.€Gregg€and€C.R.€McClain,€1992:€AnÏOverview€of€SeaWiFS€and€Ocean€Color.€€NASA€Tech.€Memo.€104566,€Vol.€1,€S.B.€HookerÏand€E.R.€Firestone,€Eds.,€NASA€Goddard€Space€Flight€Center,€Greenbelt,€Maryland,€24€pp.ÌÌHooker,€S.B.,€C.R.€McClain,€J.K.€Firestone,€T.L.€Westphal,€E„n.€Yeh€and€Y.€Ge,€1994:€TheÏSeaWiFS€Bio„Optical€Archive€and€Storage€System€(SeaBASS),€Part€1.€€NASA€Tech.€Memo.Ï104566,€Vol.€20,€S.B.€Hooker€and€E.R.€Firestone,€Eds.,€NASA€Goddard€Space€Flight€Center,ÏGreenbelt,€Maryland,€40€pp.ÌÌJohnson,€B.C.,€S.S.€Bruce,€E.A.€Early,€J.M.€Houston,€T.R.€OððBrian,€A.€Thompson,€S.B.ÏHooker€and€J.L.€Mueller,€The€Fourth€SeaWiFS€Intercalibration€Round„Robin€ExperimentÏ(SIRREX„4),€May€1995.€€NASA€Tech.€Memo.€104566,€Vol.€37,€S.B.€Hooker€and€E.R.ÏFirestone,€Eds.,€NASA€Goddard€Space€Flight€Center,€Greenbelt,€Maryland,€65pp.ÌÌMorel,€A.,€Optical€properties€of€oceanic€Case€1€waters,€revisited,€SPIE€Vol.€2963,€OceanÏOptics€XIII,€108„114,€1996.ÌÌMueller,€J.L.€and€R.W.€Austin,€1992:€Ocean€Optics€Protocols€for€SeaWiFS€Validation.€NASAÏTech.€Memo.€104566,€Vol.€5,€NASA€Goddard€Space€Flight€Center,€Greenbelt,€Maryland,Ï43pp.ÌÌMueller,€J.L.€and€R.W.€Austin,€1992:€Ocean€Optics€Protocols€for€SeaWiFS€Validation,ÏRevision€1.€NASA€Tech.€Memo.€104566,€Vol.€25,€NASA€Goddard€Space€Flight€Center,ÏGreenbelt,€Maryland,€66€pp.ÌÌMuller„Karger,€F.€E.,€C.€R.€McClain,€R.€N.€Sambrotto€and€G.€C.€Ray,€A€comparison€of€shipÏand€CZCS„mapped€distributions€o‚f€phytoplankton€in€the€Southeastern€Bering€Sea,€òòJ.€Geo‚phys.Ð Ð!   ÐRes.óó,€òò95óó(C7),€11,483„11,499,€1990.Ð ¹" ! ÐÌShaw,€P.„S.,€B.C.€Johnson,€S.B.€Hooker€and€D.€Lynch,€The€SeaWiFS€Quality€Monitor€„€aÏportable€field€calibration€light€source,€SPIE€Vol.€2963,€Ocean€Optics€XIII,€772„776,€1996.ÌÌSiegel,€D.A.,€M.C.€OððBrien,€J.C.€Sorensen,€D.A.€Konnoff,€E.A.€Brody,€J.L.€Mueller,ÏC.O.Davis,€W.J.€Rhea€and€S.€B.€Hooker,€1995:€Results€of€the€SeaWiFS€Data€Analysis€Round„¼Robin€(DARR„94),€July€1994,€NASA€Tech.€Memo.€104566,€Vol.€26,€NASA€Goddard€SpaceÏFlight€Center,€Greenbelt,€Maryland,€58€pp.