Preprints
https://doi.org/10.5194/egusphere-2022-17
https://doi.org/10.5194/egusphere-2022-17
08 Mar 2022
 | 08 Mar 2022

Ecosystem impacts of marine heat waves in the Northeast Pacific

Abigale Wyatt, Laure Resplandy, and Adrian Marchetti

Abstract. Marine heatwaves (MHWs) are a recurrent phenomenon in the Northeast Pacific that impact regional ecosystems and are expected to intensify in the future. These events, including the 2014–2015 “warm blob,” are associated with widespread surface nutrient declines across the subpolar Alaskan Gyre (AG) extending south into the North Pacific Transition Zone (NPTZ) with reduced chlorophyll concentrations confined to the NPTZ only. Here we explain the contrast between these two regions using a coupled global ocean-biogeochemical model (MOM6-COBALT) with Argo float and ship-based observations to investigate how the MHWs influence the productivity of the two primary phytoplankton size classes (large > 10 μm, small < 10 μm) and the subsequent ecosystem response. Differences in seasonal iron and nitrate limitations between the AG and NPTZ explain the differences in ecosystem response to MHWs between the two biomes. The reduced nutrient supply during MHWs most strongly influences large phytoplankton in the NPTZ (-13 % annually), whereas it has a limited impact on the climatologically iron-limited large phytoplankton population in the AG (-2 %). Contrastingly, we find that MHWs yield a springtime increase in small phytoplankton population in both regions due to shallow mixed layers and lower light limitation. These primary production anomalies modify the allometric phytoplankton distribution, resulting in a 2 % decrease in the ratio of large to small phytoplankton in both regions. This shift in the assemblage towards small phytoplankton production is associated with reduced secondary and export production especially in the NPTZ.

Journal article(s) based on this preprint

14 Dec 2022
Ecosystem impacts of marine heat waves in the northeast Pacific
Abigale M. Wyatt, Laure Resplandy, and Adrian Marchetti
Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022,https://doi.org/10.5194/bg-19-5689-2022, 2022
Short summary

Abigale Wyatt et al.

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2022-17', Anonymous Referee #1, 31 Mar 2022
    • AC1: 'Reply on RC1', Abigale Wyatt, 18 May 2022
  • RC2: 'Comment on egusphere-2022-17', Anonymous Referee #2, 11 Apr 2022
    • AC2: 'Reply on RC2', Abigale Wyatt, 18 May 2022

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2022-17', Anonymous Referee #1, 31 Mar 2022
    • AC1: 'Reply on RC1', Abigale Wyatt, 18 May 2022
  • RC2: 'Comment on egusphere-2022-17', Anonymous Referee #2, 11 Apr 2022
    • AC2: 'Reply on RC2', Abigale Wyatt, 18 May 2022

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload
ED: Reconsider after major revisions (27 May 2022) by Koji Suzuki
AR by Abigale Wyatt on behalf of the Authors (01 Jul 2022)  Author's response   Author's tracked changes   Manuscript 
ED: Referee Nomination & Report Request started (06 Jul 2022) by Koji Suzuki
RR by Anonymous Referee #2 (24 Jul 2022)
RR by Anonymous Referee #1 (26 Jul 2022)
ED: Reconsider after major revisions (01 Aug 2022) by Koji Suzuki
AR by Abigale Wyatt on behalf of the Authors (01 Sep 2022)  Author's response   Author's tracked changes   Manuscript 
ED: Referee Nomination & Report Request started (12 Sep 2022) by Koji Suzuki
RR by Anonymous Referee #2 (13 Oct 2022)
RR by Anonymous Referee #1 (16 Oct 2022)
ED: Publish subject to technical corrections (28 Oct 2022) by Koji Suzuki
AR by Abigale Wyatt on behalf of the Authors (04 Nov 2022)  Author's response   Manuscript 

Journal article(s) based on this preprint

14 Dec 2022
Ecosystem impacts of marine heat waves in the northeast Pacific
Abigale M. Wyatt, Laure Resplandy, and Adrian Marchetti
Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022,https://doi.org/10.5194/bg-19-5689-2022, 2022
Short summary

Abigale Wyatt et al.

Viewed

Total article views: 691 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
478 188 25 691 51 20 22
  • HTML: 478
  • PDF: 188
  • XML: 25
  • Total: 691
  • Supplement: 51
  • BibTeX: 20
  • EndNote: 22
Views and downloads (calculated since 08 Mar 2022)
Cumulative views and downloads (calculated since 08 Mar 2022)

Viewed (geographical distribution)

Total article views: 645 (including HTML, PDF, and XML) Thereof 645 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 23 Mar 2023
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
Marine heatwaves (MHWs) are a frequent event in the Northeast Pacific with a large impact on the region's ecosystems. Large phytoplankton in the Northeast Pacific Transition Zone are greatly affected with less of an impact in the Alaskan Gyre. For small phytoplankton, we find MHWs increase the spring small phytoplankton population in both regions thanks to shallow mixed layers and lower light limitation. In both zones, this results in a 2 % decrease in the ratio of large to small phytoplankton.