QC summit 5-7th Nov 2014

Developments in Argo Delayed Mode QC:

catering for complicated sensor

and float types

Standard Argo Float & Mission

surface

1000 m

2000 m

drift for 9 days Measure: Pressure Temperature Salinity

Expanded Argo Fleet

> 20 different float models by 12 different manufacturers

PLATFORM_TYPE MANUFACTURER

PALACE WRC

APEX WRC/TWR

APEX_EM WRC/TWR

APEX_D TWR

PROVOR MARTEC/NKE

ARVOR NKE

ARVOR_C NKE

SOLO_II SIO_IDG

SOLO_W WHOI

NEMO OPTIMARE

NAVIS SBE

NINJA TSK

NOVA METOCEAN

… …

>

Argo Enhancements

EM Argo vertical velocity

Deep Argo

Ice Argo Regional Seas / Coastal Argo

Near Surface SST/SSS

Bio Argo

New Argo Data Format V3.1

Metafiles contain information about the float: • Float characteristics • Float deployment and mission information • Float sensor information • Float calibration information • Configuration parameters

Historically, metafiles have not been consistently populated or standardised between DACs.

• Fields are incorrectly filled or empty • Non-uniform entries, i.e. “SBE41CP_1769” or “1769” • Not recording enough detail to track float failure modes, i.e. battery type or controller board type

Metadata files

Why is metadata important?

SENSOR

ACOUSTIC_PRECIPITATION

ACOUSTIC_GEOLOCATION

CTD_CNDC

CTD_PRES

CTD_TEMP

EM

FLUOROMETER_CDOM

FLUOROMETER_CHLA

IDO_DOXY

OPTODE_DOXY

RADIOMETER_DOWN_IRR

RADIOMETER_PAR

SCATTEROMETER_BBP

SCATTEROMETER_TURBIDITY

SPECTROPHOTOMETER_NITRATE

STS_CNDC

TRANSISTOR_PH

TRANSMISSOMETER_CP

…

SENSOR_MAKER

AMETEK

AANDERA

DRUCK

FSI

KISTLER

PAINE

SEASCAN

SBE

WETLABS

MBARI

SATLANTIC

…

SENSOR_MODEL

SBE41

SBE41CP

SBE41CP_V1

SBE41CP_V1.2

SBE41CP_V3.0c

SBE61CP

SBE63_OPTODE

SBE43I

AANDERAA_OPTODE_3830

AANDERAA_OPTODE_4330

DRUCK

PAINE_1500PSIA

SUNA

SATLANTICOCR507

FLNTU

ECO_PUCK

ECO_[FL]_[BB]_[BB2]_[TRIPLET]_[CD]

…

• We need to keep track of an increasing diversity of sensors and parameters..

SCIENTIFIC_CALIB_COMMENT =

PRES Pressures adjusted using PRES_SurfaceOffsetTruncatedplus5dbar_dBAR;

Pressure drift corrected; Manufacturers sensor accuracy

TEMP No significant temperature drift detected; SBE sensor accuracy

PSAL Salinity drift - correction applied using OW piecewise-fit based on deepest-

possible theta levels and Argo and CTD reference datasets.

SCIENTIFIC_CALIB_EQUATION =

PRES PRES_ADJUSTED = PRES - [PRES_SurfaceOffsetTruncatedplus5dbar_dBAR

- 5]

TEMP no change

PSAL PSAL_ADJUSTED = sal(CNDC,TEMP,PRES_ADJUSTED); PSAL_ADJ

corrects conductivity cell thermal mass (CTM), Johnson et al, 2007, JAOT

SCIENTIFIC_CALIB_COEFFICIENT =

PRES PRES_SurfaceOffsetTruncatedplus5dbar_dBAR in TECH file for N-1 profile

TEMP no change

PSAL same as for PRES_ADJUSTED; CTL: alpha=0.021, tau=21;

Calibration Fields must be filled in

• For floats with multiple missions;

– The configuration from the first cycle is set to 1.

– Each subsequent configuration change has a new mission number, i.e. from 1 to N.

Mission Parameters

CONFIG_MISSION_NUMBER

• Argo floats usually have one mission for the life of the float; i.e. CONFIG_MISSION_NUMBER = 0 (launch/pre-deployment info) and = 1 (basic mission). • Some floats now perform multiple missions, i.e. combination shallow/deep profiles.

Missions and configuration parameters

Core Argo CONFIG_AscentSpeed_mm/s CONFIG_ParkPressure_dbar CONFIG_ProfilePressure_dbar CONFIG_DownTime_hours CONFIG_IceDetection_degC

Bio Argo CONFIG_SensorInPumpedStream_LOGICAL CONFIG_OptodeMaxTransmittedTemperature_mdegC CONFIG_<short sensor name>DepthZone<N>AscentSamplingPeriod_seconds CONFIG_CroverBeamAttenuationWavelength_nm CONFIG_FlbbSampling_NUMBER

Approved Units List

COUNT NUMBER byte days hours DDMMYYYY dbar …

Core Argo files

* Physical parameters only Rwmo_XXX.nc and Dwmo_XXX.nc

B-Argo files – intermediate + final parameters BRwmo_XXX.nc and Bdwmo_XXX.nc

Merged files – core + final B-Argo parameters wmo_Mprof.nc

• Accommodates multi-profile floats [N_PROF > 1].

• Some floats make measurements at different vertical levels in the same cycle; i.e. a primary CTD profile of P, T and S at 2 db intervals from 0-1000 db and a secondary profile of low res oxy data at N discrete levels.

• PRES is the link between parameters in the core- and b- files.

Example: high res primary CTD profile with low res secondary oxygen profile:

Multi-profile files

In the core-Argo profile file, N_PROF = 2, N_LEVELS = 500 PRES = [2, 4, 6, ……………………...............1000] = [250, 500, 750, 1000, FillValue, …………] TEMP = [T2, T4, T6, ……………………….T1000] = [FillValue, ………………………………..] PSAL = [S2, S4, S6, ………………………..S1000] = [FillValue, ………………………………..]

In the b-Argo profile file, N_PROF = 2, N_LEVELS = 500. PRES = [2, 4, 6, ……………………...............1000] = [250, 500, 750, 1000, FillValue, ………....] NITRATE = [FillValue, ………………………………..] = [N250, N500, N750, N1000, FillValue, …] [Other intermediate nitrate wavelength variables at same levels as NITRATE...]

Processing Bio Argo variables: Oxygen, Chl a and Backscattering

Available at: http://www.argodatamgt.org/Documentation

Processing documents for CHLOROPHYLL A and BACKSCATTERING are in draft form and will be discussed at BioArgo workshop 3-4th Nov 2014, Canada and should be available on the ADMT website next year.

Does not address oxygen QC but seeks to ensure that all countries are documenting data and metadata correctly.

Argo Data Structure • netcdf files - traj, meta and tech files

Example profile file: R5901156_001.nc

latitude, longitude, cycle number, calibration date, scientific calibration comment etc

Raw Adjusted Raw_QC Adjusted_QC Adjusted_ERROR

PRES PRES_ADJUSTED PRES_QC PRES_ADJUSTED_QC PRES_ADJUSTED_ERROR

TEMP TEMP_ADJUSTED TEMP_QC TEMP_ADJUSTED_QC TEMP_ADJUSTED_ERROR

PSAL PSAL_ADJUSTED PSAL_QC PSAL_ADJUSTED_QC PSAL_ADJUSTED_ERROR

QC Flag Meaning

0 No QC was performed

1 Good data

2 Probably good data

3 Probably bad data that are potentially

correctable

4 Bad data

5 Value changed

6 Not used

7 Not used

8 Interpolated value

9 Missing value

Overall Profile QC flags:

POSITION_QC

PROFILE_PRES_QC

PROFILE_TEMP_QC

PROFILE_PSAL_QC

Profile

QC Flag

Meaning

“ ” No QC was performed

A N = 100%; all profile levels

contain good data

B 75% <= N < 100%

C 50% <= N < 75%

D 25% <= N < 50%

E 0% < N < 25%

F N = 0%; No profile levels have

good data

• profile files – “R” or “D” files

DMQC processing Point-wise pressure check

and QC flagging

• can view primary and secondary profiles at the same time • QC individual values and bands of bad data • can transfer primary QC to secondary if depths match

TS plot and Nearby Argo comparison

TEM

P

PSAL PSAL

DOXY

PR

ES

PR

ES New features

include: visualisation for Bio Argo parameters: DOXY PDEN OXSAT PTMP Select nearby Argo profiles for comparison: • lat/lon range • time window ± number of days

• spikes

• bad values

• biofouling • realistic data

range

• early indicator

of drift

New interface for multi-profile floats

• allows you to select and locate individual profiles • can turn off neighbouring profiles with bad data

Manual profile inspection

Section plots - bad data values, grounding, front crossings

Salt hooks

• salty by approx 0.005

• 2 deepest measurements reported at

almost identical pressures, (end of

descent and first sample of profile)

• inadequate flushing, contamination

of high salinity water from park depth

Manual profile inspection

Density inversions and point-

wise inspection of

temperature and salinity data

(Now includes conductivity

ratio)

Profile by profile flagging

- spikes, flag inversions, salt

hooks, grounded profiles

From Barker et al, JAOT, 2011

1. PRES_ADJ (cycle i) = PRES (cycle i) – SP (cycle i+1)

Surface Pressure Correction

2. Once SPO applied to PRES_ADJ → recalculate PSAL_ADJ using new PRES_ADJ

Druck microleak

Normal diaphragm

Cracks in glass to metal seals

result in slow oil leak,

depressed diaphragm,

negative SPO, eventual

electrical short

• error in salinity as a result of the thermal

inertia of the conductivity cell, see Johnson et

al, 2007

• occurs primarily in regions of strong thermal

gradients, i.e strong thermocline to well mixed

surface layer

• software calculates new PSAL_ADJ to

correct for thermal lag spikes primarily in

regions of large gradients, i.e. base of the

thermocline

Cell Thermal Mass Error

Salinity Drift Assessment

• Comparison with 3 climatologies

• CARS / WOA98, Gouretski and Koltermann,

new CARS (inc. Argo)

• Comparison with nearby Argo data

Assess salinity drift on deep potential temperature

surface – where water masses are most stable

Salinity Drift Correction • Use software written by Owens and Wong to apply a salinity drift correction.

• Calculates a delta S correction based on a linear fit to climatology (historical CTD

data + nearby Argo data).

Prototype Oxygen QC Drift GUI

Argo Data Management website:

http://www.argodatamgt.org/Media/Argo-Data-Management/Argo-Documentation/General-documentation

Further Information - Argo Manuals

Argo User’s Manual Argo QC Manual

Version 3.1 July 18 2014 Version 2.9

Dec 2013