Documentation
Floats specifications
All floats deployed have are measuring temperature, salinity, oxygen, fluorescence chlorophyll a, backscattering (at 700 nm), fluorescent dissolved ogranic matter (FDOM), and photosynthetically active radiation (PAR). The floats n0572 and n0573 are equipped with a transmissometer (650 nm). n#### are SeaBird Navis floats from the NAAMES project and are operated by the University of Maine. lovbio### and metbio### are NKE PROVOR floats and are operated by the LOV. Most floats are profiling every other day at dawn, thereafter the PAR data is not relevant in most of the cases.
- n05## are floats deployed during NAAMES I
- n06## are floats deployed during NAAMES II
- n08## are floats deployed during NAAMES III
Delayed quality check on floats and sensors
- n0646 only did 22 profiles.
- n0647 only did 167 profiles and started dysfunction during the last profile (data missing at many depth).
- n0851 PAR sensor is not working (outputs negative values).
Processing
Profiles from the NAAMES bioArgo floats are received and processed in real-time at the University of Maine and on the GDAC. The processing described below is available on our ftp.
- RAW: all msg and log received from Navis BGCi including incomplete files due to early end of transmission.
- RAW_EOT: only complete msg and log are kept.
- L0: hexadecimal data stored in msg is decoded in decimal numbers and converted to csv files.
- L1: calibrate level 0 data using manufacturer calibration coefficients (available here).
- L2: adjust and correct the data and compute additional product.
- fchl no correction are applied
- chla_adj is fchl corrected for non-photochemical quenching (Xing et al. 2012) and the manufacturer slope factor is adjusted using the HPLC of the 4 NAAMES campaigns at time of deployment of the floats (chl_HPLC = (fchl_float - 0.019) / 2.32, files used for calibration)
- bbp is computed from beta (Zhang et al, 2009, Sullivan et al. 2013)
- POC is computed from bbp
- C_phyto is computed from bbp
Table 1. List of parameters.
| Variable | Description | Units |
|---|---|---|
| profile | profile number | - |
| dt | date and time | yyyy/mm/dd hh:mm |
| lat | latitude | decimal degree North |
| lon | longitude | decimal degree East |
| p | pressure | dbar |
| t | in-situ temperature ITS-90 | deg C |
| sp | pratical salinity PSS-78 | no units |
| o2 | oxygen concentration | mL/L |
| turb | turbidity | NTU |
| fchl | chlorophyll a fluorescence | mg m-3 |
| chla_adj | chlorophyll a fluorescence adjusted | mg m-3 |
| beta | angular scatterance at 700 nm with a scattering angle of 124 | m-1 sr-1 |
| fdom | fluorescent colored dissolved organic matter (CDOM) | mg m-3 |
| ed### | downwelling irradiance at ### nm | W m-2 nm-1 |
| par | photosynthetically available radiation | μmol photons m-2 s-1 |
| c | attenuation | m-1 |
| bbp | particulate backscatter at 700 nm | m-1 |
| C_phyto | phytoplnakton carbon | mg m-3 |
| POC | particulate organic carbon | mg m-3 |
References
Sullivan, J. M., M. S. Twardowski, J. Ronald, V. Zaneveld, and C. C. Moore (2013), Measuring optical backscattering in water, in Light Scattering Reviews 7, Springer Praxis Books, edited by A. A. Kokhanovsky, pp. 189–224, Springer, Berlin, doi:10.1007/978-3-642-21907-8_6.
Zhang, X., L. Hu, and M.-X. He (2009), Scattering by pure seawater: Effect of salinity, Opt. Express, 17(7), 5698–5710, doi:10.1364/OE.17.012685.
Xing, X., H. Claustre, S. Blain, F. D’Ortenzio, D. Antoine, J. Ras, and C. Guinet (2012), Quenching correction for in vivo chlorophyll fluorescence acquired by autonomous platforms: A case study with instrumented elephant seals in the Kerguelen region (Southern Ocean), Limnol. Oceanogr. Methods, 10(7), 483–495, doi:10.4319/lom.2012.10.483.