Synthesis -recommendations

4nd Bio-Argo WorkshopNovember 2-3 2015, Bermuda

Bio-Argo Task Team: term of references(outcome of AST 15)

Within the Argo program, the Bio-Argo task team acts as a scientific committee of Bio-Argo national representatives, which provide recommendation and guidance for the progressive development and implementation of a Bio-Argo program. More specifically, its terms of reference are to:

• Develop and update the Bio-Argo science plan with respect to regional pilot projects and to a global network.

• Coordinate the implementation plan, in particular to optimize the various national efforts.• Interact with other task teams (e.g. “marginal Seas”, “polar areas”) to prepare and

coordinate the possible implementation of a Bio-Argo component to these new developments of Argo.

• Elaborate “good practice” recommendations with respect to float and sensor preparation, calibration, deployments and associated in situ simultaneous measurements.

• Provide advice regarding new variables in the BIO-Argo data stream, in particular based on an evaluation of the degree of readiness of their sensors.

• In close interaction with ADMT coordinate and organize the Bio-Argo data management.• Establish and /or strengthen interactions and exchanges with international programs

(IMBER, SOLAS) or group of experts (IOCCP, IOCCG).• Establish and develop interactions with the operational oceanography community (e.g.

Marine Ecosystem Analysis and prediction task team of GODAE OceanView)

The variables ready to be implemented

• Oxygen

• Nitrate

• pH

• Chlorophyll a

• Particulate (back)scattering

• Radiometry : Ed(λ), Photosynthetically Available Radiation (PAR)

• CDOM (Colored Dissolved Organicmatter)

Link with Oceancolour remotesensing products

Updated documentation: processing Bio-Argo

http://dx.doi.org/10.13155/39468

Updated documentation: RT QC….

O2 and bb released soon!

Processing at the DAC level RT-QC DM-QC

O2

NO3

pH

Chla

bb

radiometry

CDOM

Status of documents (version 1) related to « Bio-variables »: 2015

Done On-going To be done

Bio-Argo / BG floats floats: 2015 / 2012 / 2009

190/426

/18 / 4

/12/21

/1/0

http://www.oao.obs-vlfr.fr/maps/en/

Easy visualisation toolFrom custom « files » to argo format 3.1

O2• Adoption of air-sea measurement (SCOR WG 142)

recommendation• In water calculation : use the SCOR WG recommendations• Create new parameter name PPOX (table 3) cover the

requirement to take into consideration in air-measurements• Time information from profile measurements will be stored

in the b-traj file??• In air measurements will be in the trajectory file (proposition

2 of Megan: “new measurement codes”).• Document the length of the stick (for the above water) in the

metadata file.• If air calibration become the rule what about the “in the

flow” optodes?

Radiometry

• Documentation “processing the radiometry at the DAC level” at Coriolis: should be released soon

• RT-QC: LOV has developed a procedure (submitted paper to JAOT) that will be implemented at Coriolis and adapted to the philosophy of Argo QC

• RT-QC should be adapted (new parameters?) for accommodating two type of end-users: – Optical / spatial agency community: clean, cloud-free or

overcast profiles required: shape– Other (primary production / photosynthesis): magnitude

• DM-QC– Comparison of float irradiance extrapolated to the surface

with “clear sky model” irradiance– Monitoring sensor performance at depth (drift)

Channel Type 1 Type 2 Type 3 Type 4

Ed(380) 58% 22% 7% 13%

Ed(412) 67% 9% 10% 14%

Ed(490) 56% 15% 9% 20%

PAR 57% 16% 9% 18%

ALL 60% 15% 9% 16%

6570 profilesFor each channel,For 65 floats

Radiometry RT-QC

Backscattering (bb)• RT-QC documentation (V1) finished: Doi: • Code will be implemented and tested at Coriolis• Interact with Zhang to have his code/look up table

(DOI?) included in Argo data system.• FLBB and FNTU sensor users should interact and

coordinate with Catherine for implementing the procedure (“processing the scattering measurement at the DAC level”)

• DM QC: – at the moment validation possible only with surface bb from

remote sensing – No data base of reference (on going work : neural network

using Argo TS and Ocean Color Radiometry to produced)

NO3• Defining/Adjusting the dimension for metadata file for the

variable PREDEPLOYMENT_CALIB_COEFFICIENT/EQUATION to fit with nitrate calibration – Catherine

• Move the vertical_pressure_offset from configuration to metadata

• Finishing the document « processing NO3 at the DAC level » + adjustment (“pressure” effect and vertical offset included)– Catherine and Ken and Orens

• Still Need discussion / agreement for (RT)-QC document for nitrate (but first draft highly needed): – Ken, Carol Sakamoto, Orens& Catherine

• Need to define what is relevant from RT-QC from DM-QC, NRT-QC (use of reference deep data, WOA, MLR method)

pH• Preparing the document « processing pH at the DAC

level » after paper submission by Ken• Preparing (RT)-QC document for pH: • Need to define what is relevant from RT-QC from

DM-QC, NRT-QC (use of reference deep data, MLR method)

*Xing X, et al. (2011) Combined processing and mutual interpretation of radiometry and fluorimetry from autonomousprofiling Bio-Argo floats: Chlorophyll a retrieval. J Geophys Res-Oceans 116 | doi: 10.1029/2010jc006899.

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

MED SEA

NAT Sub-polar Gyre

SouthernOcean

Overestimation of Chla by fluorescence

1.9

7.6

1.7 & 1.9

4.0

• There is presently a bias in the satellite vs float Chla (adjusted) relationships

• This biais is not the consequence of the quenching correction which is a legitimate correction (profiling at night is not necessary)

• Rather the Wetlabs calibration is questionable and an overestimation factor of 2 seems systematic (taking into consideration for producing RT-Chla?)– Wetlabs representative are coming at LOV in December – We have requested they do not change anything without any

notice• Beside the overestimation factor, there is a consistent

regional (natural) biais in the relationship (float vs HPLC Chla) or (float vs radiometric Chla) that is of more concern for producing DM-Chla.

Summary for Chla Biais

« deep fluorescence signal »

• DM: there is a possibility to correct the « non-Chla » fluorescence increase with depth using information on the slope of CDOM increase. We begin to have sufficient data to make a regional test and correction?

• This correction might be especially appropriate (required) for sub-tropical gyres where it would impact the surface (extremely) low values..

DM discussion• Need to define what is relevant from RT-QC from DM-QC,

NRT-QC• Reference dataset might be an issue but not necessary:

– O2 in air measurement– Radiometry : compare with a surface reference model for “clear

sky) and monitor the evolution of biais– Chla : time / space scale issues = > bio-regionalization?

• Feedback from salinity DM operators to set up DM Bio-Argo– One contact point Argo Netcdf specialist but…– Various experts for « each variable »– Consider to cross-check different variable (e.g. radiometry vs

Chla)• Develops tools for Bio-Variables DM as “module” of a generic

tool– Need to share and exchange

• Foster exchange between DAC/national contact to help in setting up the Bio-Argo QC procedure

• Developing test cases between DACs to compare computation and QC results

• Update RT QC documention (V2)• « Flash news » for the Bio-Argo data end-users with

respect to prototype character of our data• Better communicate on the documentation as soon as

it become available through the Argo-Bio « list ».• Develop a Bio-Argo Web site

– Archive papers / documentation that support Bio-Argo science behind data managment

• Summer school / training / capacity building

Some more general recommandations

Planning a global BioGeoChemical-Argo networkVillefranche-sur-mer, January 11-13, 2016

Anticipated program:• 1 day: review the science questions that the network would

address• 1.5 days: present and discuss methods & metrics for sizing the

array according to science questions. OSSEs, bio-regionalization…• 0.5 day: elaborate a first draft of recommendations/ executive

summary.

The need to elaborate the Bio-Argo design for the global scalePlanning a global BioGeoChemical-Argo network

Villefranche-sur-mer, January 11-13, 2016

For all presenters of the last two days: please send 5-10line summary of your presentation to Catherine andmyself before the end of the meeting.

Thanks !