data delivery and real me data quality flags

Changingdynamicsofwaterqualityandnutrientmonitoringthroughtheuseoflongtermuna6endeddeployments,real9me

datadeliveryandreal9medataqualityflags

Nichole Halsey, Corey Koch,

Bruce Rhoades Adam Dutton

Sea-Bird Scientific Doug Wilson

Caribbean Wind LLC

ChangingDynamicsofWaterQualityandNutrientMonitoring

HydroCycle-PO4PhosphateSensor

Range: PO4

3- : 2.3-1200 µgP/L Accuracy: PO4

3- : ~4.6 µgP/L (extensive grab sample in field operation) Endurance: PO4

3- : 9-18 weeks (hourly-bihourly interval) Field service: PO4

3- : optics clean, new reagent cartridges, filters

ABSTRACTTheCycle-PO4wasdesignedforestuarineresearch,buthasbeenadoptedbymanywater

qualitysensorusers.Thelatestversion,theHydroCycle-PO4,offersanimprovedplaEormtoprovideawetchemicalinstrumentforcon9nuousmonitoringinbothfreshandcoastalwaters.TheHydroCycle-PO4hasincreasedreliabilityoveritspredecessorbymaximizinginstrumentup9me.Fluidicshavebeenadvancedtoprovide>90%up9mefreeofbubblesforopera9oninhighoxygensatura9onenvironments.Filterlifehasbeenextendedtominimizecloggingandincreasethe9mebetweenserviceintervals.Theseimprovementspermitphosphatemeasurementinawidervarietyofcondi9onsandprovideaninstrumentbe6ersuitedforapplica9onssuchasagriculturalrunoffmonitoring.Achallengeinservingandvisualizingreal-9medatafromin-situsensorsisqualifyingthedata.With“QualityAssuranceofReal-TimeOceanData”asaguide,wehavedevelopedsensor-specificQualityControl(QC)flagstoalertusersofSuspect/HighInterest,Bad,orGooddata.Flagsarebasedonalgorithmson-boardthesensorthatusesensorspecificmeta-dataandsitedefinedthresholdstoqualifysensorperformanceanddataqualityforeachdatum.Examplesincludeout-of-range,lowsignal,etc.So]wareisusedtoinves9gateHighInterestdataandprovidequalitysta9s9cs.Qualifieddatacanbepresentedtothecommunityinreal9me.Ul9mately,flaglevelscanbeusedtohelpautomateclassifica9onofdatasostakeholderscanmakebe6erdecisionsandscien9stscanquicklyiden9fyqualitydataforuseinanalysisandmodels.Pilotcollec9onofautoma9callyQC’edphosphatedataishappeningnowinanumberofsites.Usersarestudyingphosphorusfrom9dal,estuarine,andterrestrialsources,requiringhighfrequencyobserva9onstounderstandecosystemimpacts.MechanismsbywhichautomatedQCareperformed,howqualitymeta-datacanbeusedinthedatamanagement,web-publishing,visualiza9on,andthesignificanceofreal-9mephosphatewillbepresented.

TheHydroCycle-PO4isawetchemicalsensorengineeredforenvironmentalmonitoringtoenablevalid,scien9ficallydefensibleresultsthatleadtobe6ermanagementrecommenda9ons.ANISTtraceableon-boardstandard,factorycalibra9oncheck,a2.3µgP/Ldetec9onlimit,andanaccuratecalibra9onmeanyoucantrustdata,lineupgrabsamplerecords,andswapsensorswithminimaloffsets.Autonomousopera9ons,low-power,fivemonthreagentstabilityenableextendeddeploymentsinremoteloca9ons.Over1000samplesbetweenservices,uptofoursamplesperhourandbothSDI-12andRS232permitcapturinghigherfrequencyphosphatedatathanbefore.TheHydroCycle-PO4hasincreasedreliabilityoveritspredecessor,theCycle-PO4,andmanywet-chemicalsensors,bymaximizingdatareliabilityandsensorup9me.Fluidicshavebeenadvancedtoprovide>90%up9mefreeofbubblesfordataqualityinhighoxygensatura9onenvironmentsandtoensureitstabilizesrapidlya]erdeployment.Filterlifehasbeenextendedtominimizecloggingandenhancedataqualityduringhighsedimentevents.

RealTimeQualityControlFlagsThissystemofautomatednutrientsensorswilldeliverhigh-frequency,quality-controllednutrientdatatoscien9sts,managers,andpolicymakerstohelpunderstandnaturalandanthropogenicinfluencedcoastalnutrientdynamicsthroughouttheregion.Qualitycontrol(QC)flagsprovideconfidenceinthedataqualityandup9mesouserscanknowtheirinstrumentisworkingproperly.QCflagscanhelpspeeduptroubleshoo9ng,helpjus9fypublisheddata,andpermituserstospendmore9meonadvanceddataanalysisratherthanreviewingdatatoseparategooddatafrombad.UsingthissystemofQCflagseachdatapointreceivesageneralqualityflag(good,suspect,orbad)inreal9me.Thisflagisacompositeofthesixindividualqualityflags.Thoseflagsinclude:out-of-rangemeasurement,op9calnoise,lowsignal,bubblesandcalibra9onandmixingspikes.Theincludedso]warecanbeusedtoinves9gatehighinterestdataandprovidequalitysta9s9cs.Dataisautoma9callycolorcodedGreen(Good),Yellow(Suspect),Red(Bad)andBlue(NotEvaluated).

TradiEonalMethod:GrabSampleSite~12–24measurementsperyear

CurrentMonitoringTrend:RealTimeSitewithNutrientSensors~315,000measurementperyear

Waterisafiniteresourcevitalforhumanlife.Itisakeyingredientinagriculture,manufacturing,energycrea9on,andtransporta9on.Currentlyouraqua9cecosystemsarethreatened,locallyandgloballybyavarietyofpollutantsasresultofpopula9ongrowth,industrialgrowthandlarge-scaleagriculture.Pointandnon-pointsourcesincludedomes9csewage,agriculturalrun-offandindustrialeffluents.Therateandimpactofnutrientpollu9onisgrowingandiscontribu9ngtoacceleratedeutrophica9oninlakesandimpoundedrivers.Impactstoaqua9csystemscanoccurinawiderangeof9mescalesandbasedonanumberoffactors.

NERRSMyrtleBeachDeploymentACycle-PO4sensorwasdeployedintheWithersSwash,inlatewinterof2013throughthesummer.Itwasmountedinacageanddeployedalongthebo6omatasitebyFamilyKingdom.ALOBOsystem,includingaCycle-PPhoshatesensor,wasdeployedatWithersSwash,SC,partoftheNorthIsland–WinyahBayNa9onalEstuarineResearchReserve.Figure1showsPO4readingstakenoverthefirsthalfof2013.Alldataareshownwithreddatapointshighligh9ngvaluesdeemedinvalidbyautomatedanalysiswithintheCycle-Psampleprocessingsystem.SimilaranalysisisnowincludedandoutputbyCycleinstrumentsalongwithreal9medata.

Conclusions•  Anaddi9onalfeatureoftheQualityControlflagsisthattheycanbeappliedtoanyCycledata-Herewepost-processeddatafroma2013deploymentbeforewehaddevelopedQCflagsorimprovedthesensor’sfilters•  Over4113samples—6monthsofcon9nuoushourlydata—73%ofthedatawasgood,10%suspect,and17%ofthedatawasbad

-Unitservicedon3/12,4/22,and6/4-SomebaddatainMarchandJuneduetorunningoutofreagentandlatentreagentprimingissues-ThemajorityofthebaddataisduetothebubbleflagonApril1thatgoesun9lMay,thenshorterstretchesofbaddatain

mid-Juneandmid-July•  Consistentbadbubbleflagshalfwaythroughthedeploymentisasignthatfiltersneedtobeserviced.A]erchangingthefiltersthebaddatabecomesgoodagain

-Theeventhadseveralsuspectflagsandintermi6entbadflagson3/31that,ifavailablein2013,wouldhavealertedustochangethefiltersandnotlosedataqualityforthemonthofApril

-Theregularfrequencyoffilterclogginginthissystemisaboutevery4-5weeksduringtheproduc9veseason,nowHydroCycle-PO4'sfilterslastover3Xlonger,butweshouldhaveconsideredchangingourserviceschedule!

RESULTS

Measurementsofnutrientsprovidedformoreaccuratees9matesofphosphateloadings.Threemethodsare

comparedbasedon:1)Cycle-PO4measurement,2)LinearInterpola9onofgrabsamples,and3)Linearregressionofgrab

sampleswithdischarge.

Myrtle Beach is a popular tourist site in a 60 mile stretch of beaches that support a multi-billion dollar tourism industry in South Carolina. In this area much of the storm water flows in to tidal creeks known as swashes that travers the beaches and flow directly in to the ocean. Because of this local scientists and regulators were interested in studying how swashes collect, transform, and export the nutrients from the runoff in to the coastal ocean waters. Cycle-PO4 Linear

Interpolation Discharge

Regression Aug Load (kg) 5.8 7.8 8.4 Sept Load (kg) 12.5 13.1 10.4

0

2

4

6

8

10

12

14

Load

(kg/

mon

th)

OverallQCBubbleSpikeFlag QCCOVFlag

QCLowSignalFlag

QCOutOfRangeFlag

QCMixingSpikeFlag

QCCalSpikeFlag

samplecount 4113 4113 4107 4107 3737 4023 603

%Good 73 86 93 100 97 83 96%Suspect 10 2 7 0 2 8 2

%Bad 17 12 0 0 1 9 2

OverallQCBubbleSpikeFlag

QCCOVFlag

QCLowSignalFlag

QCOutOfRangeFlag

QCMixingSpikeFlag

QCCalSpikeFlag

samplecount 4113 4113 4107 4107 3737 4023 603%Good 73 86 93 100 97 83 96%Suspect 10 2 7 0 2 8 2%Bad 17 12 0 0 1 9 2

Whythewidedatarange?WithersSwashischaracterizedbyfree9dalexchangewiththeAtlan9cOceanthroughanopenchannelcrossingthebeach.Thedrainagebasinisalsosignificantlyaffectedbystormwaterrunoff.Figure2showsthefirstdeployment(JFM)PO4(aswellasNO2+3fromacoincidentallylocatedSUNANitrateSensor)asafunc9onofHighWater/LowWateraswellaslocalprecipita9on,showingthestronginfluencesofbothoceanfloodingandstormwaterrunoff.Withthislevelofvariability,havingaccesstoreal9medataqualityinforma9onisvitaltomaintainingcon9nuousconfidenceinthevalidityofthedata.