Preprints
https://doi.org/10.5194/bg-2022-9
https://doi.org/10.5194/bg-2022-9
13 Jan 2022
 | 13 Jan 2022
Status: this discussion paper is a preprint. It has been under review for the journal Biogeosciences (BG). The manuscript was not accepted for further review after discussion.

Observing intermittent biological productivity and vertical carbon transports during the spring transition with BGC Argo floats in the western North Pacific

Chiho Sukigara, Ryuichiro Inoue, Kanako Sato, Yoshihisa Mino, Takeyoshi Nagai, Andrea J. Fassbender, Yuichiro Takeshita, Stuart Bishop, and Eitarou Oka

Abstract. To investigate changes in ocean structure during the spring transition and responses of biological activity, two BGC-Argo floats equipped with oxygen, fluorescence (to estimate chlorophyll a concentration – Chl a), backscatter (to estimate particulate organic carbon concentration – [POC]), and nitrate sensors conducted daily vertical profiles of the water column from a depth of 2000 m to the sea surface in the western North Pacific from January to April of 2018. Data for calibrating each sensor were obtained via shipboard sampling that occurred when the floats were deployed and recovered. During the float-deployment periods, repeated meteorological disturbances passed over the study area and caused the mixed layer to deepen. After deep-mixing events, the upper layer restratified and nitrate concentrations decreased while Chl a and POC concentrations increased, suggesting that spring mixing events promote primary productivity through the temporary alleviation of nutrient and light limitation. At the end of March, POC accumulation rates and nitrate decrease rates within the euphotic zone (0–70 m) were the largest of the four events observed, ranging from +84 to +210 mmol C m−2 d−1 and –28 to –49 mmol N m−2 d−1, respectively. The subsurface consumption rate of oxygen (i.e., the degradation rate of organic matter) after the fourth event (the end of March) was estimated to be –0.62 micromol O2 kg−1 d−1. At depths of 300–400 m (below the mixed layer), the POC concentrations increased slightly throughout the observation period. The POC flux at a depth of 300 m was estimated to be 1.1 mmol C m−2 d−1. Our float observation has made it possible to observed biogeochemical parameters, which previously could only be estimated by shipboard observation and experiments, in the field and in real time.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Chiho Sukigara, Ryuichiro Inoue, Kanako Sato, Yoshihisa Mino, Takeyoshi Nagai, Andrea J. Fassbender, Yuichiro Takeshita, Stuart Bishop, and Eitarou Oka

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on bg-2022-9', Anonymous Referee #1, 16 Feb 2022
    • AC1: 'Reply on RC1', Chiho Sukigara, 14 Mar 2022
  • RC2: 'Comment on bg-2022-9', Anonymous Referee #2, 25 Feb 2022
    • AC2: 'Reply on RC2', Chiho Sukigara, 14 Mar 2022

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on bg-2022-9', Anonymous Referee #1, 16 Feb 2022
    • AC1: 'Reply on RC1', Chiho Sukigara, 14 Mar 2022
  • RC2: 'Comment on bg-2022-9', Anonymous Referee #2, 25 Feb 2022
    • AC2: 'Reply on RC2', Chiho Sukigara, 14 Mar 2022
Chiho Sukigara, Ryuichiro Inoue, Kanako Sato, Yoshihisa Mino, Takeyoshi Nagai, Andrea J. Fassbender, Yuichiro Takeshita, Stuart Bishop, and Eitarou Oka
Chiho Sukigara, Ryuichiro Inoue, Kanako Sato, Yoshihisa Mino, Takeyoshi Nagai, Andrea J. Fassbender, Yuichiro Takeshita, Stuart Bishop, and Eitarou Oka

Viewed

Total article views: 1,134 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
828 265 41 1,134 32 34
  • HTML: 828
  • PDF: 265
  • XML: 41
  • Total: 1,134
  • BibTeX: 32
  • EndNote: 34
Views and downloads (calculated since 13 Jan 2022)
Cumulative views and downloads (calculated since 13 Jan 2022)

Viewed (geographical distribution)

Total article views: 1,085 (including HTML, PDF, and XML) Thereof 1,085 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 11 Jun 2024
Download
Short summary
To investigate the physical changes in the ocean from winter to spring and the corresponding biological activities, two automated floats were used to conduct observations in the western North Pacific from January to April 2018. During the observation, repeated storms passed and mixed the ocean surface layer. Afterwards, active biological activity was observed. Using data from the float, we observed the formation, decomposition, and settling of particulate organic matter.
Altmetrics