V3.4.1L2ResidualSSSRetrievalBias

LiangHong,JoelGales3/31/2015

Outline• ResidualdSSS inV3.4.1isstillslightlypositive(~0.04PSU)forallbeams,similartoallpreviousversionsbacktoV2.8– OrbitalaverageofresidualSSSretrievalerror(comparedtoHYCOM)foreachbeamusingglobaldataarecheckedasverificationforradiometergainandoffsetcorrections

– TagainandoffsetcorrectionsareimplementedsuchthatdTa =Tf – Ta_exp isabout0forallbeams• i.e.substituteTf withTa_exp inAquariusSSSretrievalmodelwon’tgetexactsameHYCOMsalinity.

– dSSS changedslightlybetweenV2.5andV2.8• LatitudinaldistributionofdSSS inV3.4.1ischangedfromV3.0

SSS– HYCOMorbitalavg.

- V3.4.1bothstandarddeviationandbiasarenearlyunchangedfromV3.3(V3.0+SWHcorrection)- ThedSSS biasesarelightlymoreconsistentamong3beamsinV3.4.1

V3.4.1dTa

dTa =Tf – Ta_exp isflattenedto0forallchannels

V2.2.1dSSS

-Datafilteredusingsamecriteriaasforcalibrationcorrection- V2.2.1hasexponentialdriftcorrectionandflatteningoffset(wiggle)correctionapplied

V2.5.1dSSS

V2.4.1usedtheprelaunchRFIthresholdsinplaceoftherevisedthresholdsthatwereimplementedforV2.0V2.5.1usedtheupdatedgalaxycorrectiondevelopedbyRSS.-- (http://oceancolor.gsfc.nasa.gov/WIKI/AQ(2f)GS(2f)SW(2f)UpdatesPostLaunch.html)

V2.8.1dSSS

V2.6.1usedtheupdatedflagdefinitionsprovidedbyD.Levine.V2.7.1incorporatedsomecorrectionstothequalityflags,theuseoftheflagsinthecalibrationdetermination,andanupdatedSSSclimatologyfilefromRSS.AproblemwasidentifiedintheupdatedSSSclimatologyfileusedfortheV2.7.1processing.Thevaluesweresetto0forareaswithiceconcentrations,causinganomalousbehaviorinthewinddeterminationandroughnesscorrectionatextremelatitudes.V2.8.1includedthecorrectedSSSclimatologyfileandsomefinalcorrectionstothequalityflags.(V3.0equivilant)

OrbitalavgdSSSchangedtoslightpositivevalues

SSS– HYCOMLatitudinalDependence

- V3.3SSS_adj:-0.05to0.2PSUbiasalonglat.Asc +Dsc- V3.4.1SSS:-0.1to0.25PSUbiasalonglat.Asc +Dsc

• NegativedSSS’s intropicsandpositivedSSS’s athigherlat.• SymmetricpatternsinAsc/Dsc

V3.3SST_adj V3.4.1

Beam1

- V3.3:-0.1to0.2PSUbiasalonglat.Asc +Dsc- V3.4.1:-0.1to0.25PSUbiasalonglat.Asc +Dsc- Bothlatitudinaldependenceconsistentovertime- V3.4.1:tropicalSSSretrievallowervaluethanV3.3

V3.3SST_adj V3.4.1

Beam2V3.3SST_adj V3.4.1

- V3.3:-0.05to0.1PSUbiasalonglat.Asc +Dsc;- V3.4.1:-0.15to0.15PSUbiasalonglat.Asc +Dsc;-BothV3.3&V3.4:latitudinaldependenceconsistentovertime- V3.4.1SSS:tropicalSSSretrievallowervaluethanV3.3

Beam3V3.3SST_adj V3.4.1

- V3.3:-0.1to0.35PSUbiasalonglat.Asc +Dsc;- V3.4.1:-0.1to0.4PSUbiasalonglat.Asc +Dsc;- Bothlatitudinaldependenceconsistentovertime- V3.4.1SSS:tropicalSSSretrievallowervaluethanV3.3

V3.4.1L2CalibrationCorrectionSummary

• SSSresidualbiasinV3.4.1– Rainnotfilteredinanalysis– InV3.4.1,forbothascendinganddescendingpathsandall3beams,SSSvaluesintropicalareaarelowerthanV3.3

– GlobalaverageofV3.4.1beamdifferencesofSSSbiasareslightlysmallerthanV3.3

– SlightpositiveSSSbiasesexistinallbeamsonglobalaveragebasis(V2.8-V3.4)

• HowdoweevaluateSSSretrievalsglobally– Rainfilter?SSTfilter?...

backup

SSS– HYCOMorbitalavg.

OrbitalerrorstdgreatlyreducedafterSSSadjustmentMinordropinorbitalerrormean

afterSSSadjustment

SSS– HYCOMLatitudinalDependence

- StandardSSS:-0.2to0.3PSUbiasalonglat.Asc +Dsc• NegativedSSS’s intropicsandpositivedSSS’s athigherlat.• SymmetricpatternsinAsc/Dsc

- Biasadj.SSS:-0.05to0.2PSUbiasalonglat.Asc +Dsc

StandardSSS AdjustedSSS

Beam1StandardSSS AdjustedSSS

- StandardSSS:-0.2to0.2PSUbiasalonglat.Asc +Dsc- Biasadj.SSS:-0.05to0.1PSUbiasalonglat.Asc +Dsc

Beam2StandardSSS AdjustedSSS

- StandardSSS:-0.25to0.3PSUbiasalonglat.Asc +Dsc- Biasadj.SSS:-0.05to0.15PSUbiasalonglat.Asc +Dsc

Beam3StandardSSS AdjustedSSS

- StandardSSS:-0.2to0.45PSUbiasalonglat.Asc +Dsc- Biasadj.SSS:-0.1to0.35PSUbiasalonglat.Asc +Dsc

Cal/Valdatafilter• 3) LAND (no yellow or red)• 4) ICE (no yellow or red)• 5) WIND (no yellow or red winds, no HH or HHH wind non-

convergence, scatterometer RFI)• 12) NAV (no bad attitude or off-earth)• 13) SA_OVERFLOW (overflow bit set in NRT telemetry)• 14) ROUGH (no roughness table out-of-bounds, missing SWH

value)• 16) POINTING (no non-science mode or pointing anomalies)• 17) TBCONS (no emissivity = NaN)• 18) COLDWATER (no SST < 5C)• 19) TFTADIFF (tf-ta: no yellow or red)• 21) REFL_1STOKES (no yellow or red moon or galaxy

contamination)• 23) RFI_REGION (no bad RFI geographic regions)