Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Discussion papers | Copyright
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 13 Jul 2018

Research article | 13 Jul 2018

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Biogeosciences (BG).

Carbon Flux Explorer Optical Assessment of C, N and P Fluxes

Hannah L. Bourne1, James K. B. Bishop1,2, Todd J. Wood2, Timothy J. Loew2, and Yizhuang Liu1 Hannah L. Bourne et al.
  • 1Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, 94720, USA
  • 2Lawrence Berkeley National Laboratory, Berkeley, 94720, USA

Abstract. The magnitude and controls of particulate carbon exported from surface waters and its remineralization at depth are poorly known. The Carbon Flux Explorer (CFE), a Lagrangian float-deployed imaging sediment trap, has been designed to optically measure the hourly variations of particle flux to kilometer depths for months to seasons while relaying data in near-real time to shore via satellite without attending ships. The main optical proxy of particle load recorded by the CFE, volume-attenuance (VA; units of mATN-cm2), while rigorously defined and highly precise, has not been robustly calibrated in terms of particulate organic carbon (POC), nitrogen (PN), and phosphorus (PP). In this study, a novel 3D printed particle sampler using cutting edge additive manufacturing was developed and integrated with the CFE. Two such modified floats (CFE-Cals) were deployed a total of 15 times for 18-24-hour periods to gain calibration imagery and samples at depths near 150 meters in four contrasting productivity environments during the June 2017 California Current Ecosystem – Long Term Ecological Research (LTER) process study. Regression slopes for VA:POC and VA:PN (units mATN-cm2:mmol; R2 in parentheses) were 10.07×103 (0.86), 10.05×104 (0.87) respectively and was not sensitive to environment or classes of particles sampled. PP was not strongly correlated with VA.

Hannah L. Bourne et al.
Interactive discussion
Status: open (extended)
Status: open (extended)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Hannah L. Bourne et al.
Hannah L. Bourne et al.
Total article views: 400 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
344 55 1 400 11 1 1
  • HTML: 344
  • PDF: 55
  • XML: 1
  • Total: 400
  • Supplement: 11
  • BibTeX: 1
  • EndNote: 1
Views and downloads (calculated since 13 Jul 2018)
Cumulative views and downloads (calculated since 13 Jul 2018)
Viewed (geographical distribution)
Total article views: 400 (including HTML, PDF, and XML) Thereof 399 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
No saved metrics found.
No discussed metrics found.
Latest update: 23 Oct 2018
Publications Copernicus
Short summary
The biological carbon pump, the process by which carbon-laden particles sink out of the surface ocean, is dynamic and fast. The use of autonomous observations will better inform carbon export simulations. The Carbon Flux Explorer was developed to optically measure hourly variations of particle flux. Here, we calibrate the optical measurements of the CFE against C and N flux using samples collected during a coastal California cruise in June 2017. Our regression results yield strong calibrations.
The biological carbon pump, the process by which carbon-laden particles sink out of the surface...