Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 2.864 IF 2.864
  • IF 5-year value: 3.337 IF 5-year
    3.337
  • CiteScore value: 4.5 CiteScore
    4.5
  • SNIP value: 1.259 SNIP 1.259
  • IPP value: 3.07 IPP 3.07
  • SJR value: 1.326 SJR 1.326
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 52 Scimago H
    index 52
  • h5-index value: 30 h5-index 30
Preprints
https://doi.org/10.5194/os-2020-72
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-2020-72
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  30 Jul 2020

30 Jul 2020

Review status
This preprint is currently under review for the journal OS.

Norwegian Sea net community production estimated from O2 and prototype CO2 optode measurements on a Seaglider

Luca Possenti1, Ingunn Skjelvan2, Dariia Atamanchuk3, Anders Tengberg4, Matthew P. Humphreys5, Socratis Loucaides6, Liam Fernand7, and Jan Kaiser1 Luca Possenti et al.
  • 1Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, UK
  • 2NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Bergen, Norway
  • 3Dalhousie University, Halifax, Canada
  • 4University of Gothenburg, Sweden
  • 5NIOZ Royal Netherlands Institute for Sea Research, Department of Ocean Systems (OCS), and Utrecht University, Texel, the Netherlands
  • 6National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK
  • 7Centre for Environment, Fisheries and Aquaculture Sciences, Lowestoft, UK, NR33 0HT

Abstract. We report on a pilot study using a CO2 optode deployed on a Seaglider in the Norwegian Sea for 8 months (March to October 2014). The optode measurements required drift- and lag-correction, and in situ calibration using discrete water samples collected in the vicinity. We found the optode signal correlated better with the concentration of CO2, c(CO2), than with its partial pressure, p(CO2). Using the calibrated c(CO2) and a regional parameterisation of total alkalinity (AT) as a function of temperature and salinity, we calculated total dissolved inorganic carbon concentrations, CT, which had a standard deviation of 10 µmol kg−1 compared with direct CT measurements. The glider was also equipped with an oxygen (O2) optode. The O2 optode was drift-corrected and calibrated using a c(O2) climatology for deep samples (R2 = 0.89; RMSE = 0.009 µmol kg−1). The calibrated data enabled the calculation of CT – and oxygen-based net community production, N(CT) and N(O2). To derive N, CT and O2 inventory changes over time were combined with estimates of air-sea gas exchange and entrainment of deeper waters. Glider-based observations captured two periods of increased Chl a inventory in late spring (May) and a second one in summer (June). For the May period, we found N(CT) = (24±5) mmol m−2 d−1, N(O2) = (61±14) mmol m−2 d−1 and an (uncalibrated) Chl a peak concentration of craw(Chl a) = 3 mg m−3. During the June period, craw(Chl a) increased to a summer maximum of 4 mg m−3, which drove N(CT) to (64±67) mmol m−2 d−1 and N(O2) to (166±75) mmol m−2 d−1. The high-resolution dataset allowed for quantification of the changes in N before, during and after the periods of increased Chl a inventory. After the May period, the remineralisation of the material produced during the period of increased Chl a inventory decreased N(CT) to (−80±107) mmol m−2 d−1 and N(O2) to (−15±27) mmol m−2 d−1. The survey area was a source of O2 and a sink of CO2 for most of the summer. The deployment captured two different surface waters: the Norwegian Atlantic Current (NwAC) and the Norwegian Coastal Current (NCC). The NCC was characterised by lower c(O2) and CT than the NwAC, as well as lower N(O2), N(CT) and craw(Chl a). Our results show the potential of glider data to simultaneously capture time and depth-resolved variability in CT and O2.

Luca Possenti et al.

Interactive discussion

Status: open (until 24 Sep 2020)
Status: open (until 24 Sep 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Luca Possenti et al.

Luca Possenti et al.

Viewed

Total article views: 164 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
131 31 2 164 0 1
  • HTML: 131
  • PDF: 31
  • XML: 2
  • Total: 164
  • BibTeX: 0
  • EndNote: 1
Views and downloads (calculated since 30 Jul 2020)
Cumulative views and downloads (calculated since 30 Jul 2020)

Viewed (geographical distribution)

Total article views: 75 (including HTML, PDF, and XML) Thereof 75 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 12 Aug 2020
Publications Copernicus
Download
Short summary
A Seaglider was deployed for 8 months in the Norwegian Sea mounting an oxygen and for the first time a CO2 optode and a chlorophyll fluorescence sensor. The oxygen and CO2 data were used to assess the spatial and temporal variability and calculate the net community production, N(O2) and N(CT). The dataset was used to calculate net community production from inventory changes, air-sea flux, and entrainment.
A Seaglider was deployed for 8 months in the Norwegian Sea mounting an oxygen and for the first...
Citation