Vertical Carbon Export During a Phytoplankton Bloom in the Chukchi Sea: Physical Setting and Frontal Subduction

Pickart, Robert S.; Spall, Michael A.; Bahr, Frank; Lago, Loreley; Lin, Peigen; Pacini, Astrid; Mills, Matthew; Huang, Jie; Arrigo, Kevin R.; van Dijken, Gert; McRaven, Leah T.; Roberts, Steven

doi:10.1029/2024JC021465

i

Vertical Carbon Export During a Phytoplankton Bloom in the Chukchi Sea: Physical Setting and Frontal Subduction

Supporting Files

2024
By Pickart, Robert S. ; Spall, Michael A. ; Bahr, Frank ; ...

Details

Journal Title:

Journal of Geophysical Research: Oceans
Personal Author:

Pickart, Robert S. ; Spall, Michael A. ; Bahr, Frank ; Lago, Loreley ; Lin, Peigen ; Pacini, Astrid ; Mills, Matthew ; Huang, Jie ; Arrigo, Kevin R. ; van Dijken, Gert ; McRaven, Leah T. ; Roberts, Steven
NOAA Program & Office:

OAR (Oceanic and Atmospheric Research) ; CINAR (Cooperative Institute for the North Atlantic Region)
Description:

In order to quantify pelagic-benthic coupling on high-latitude shelves, it is imperative to identify the different physical mechanisms by which phytoplankton are exported to the sediments. In June–July 2023, a field program documented the evolution of an under-ice phytoplankton bloom on the northeast Chukchi shelf. Here, we use in situ data from the cruise, a simple numerical model, historical water column data, and ocean reanalysis fields to characterize the physical setting and describe the dynamically driven vertical export of chlorophyll associated with the bloom. A water mass front separating cold, high-nutrient winter water in the north and warmer summer waters to the south—roughly coincident with the ice edge—supported a baroclinic jet which is part of the Central Channel flow branch that veers eastward toward Barrow Canyon. A plume of high chlorophyll fluorescence extending from the near-surface bloom in the winter water downwards along the front was measured throughout the cruise. Using a passive tracer to represent phytoplankton in the model, it was demonstrated that the plume is the result of subduction due to baroclinic instability of the frontal jet. This process, in concert with the gravitational sinking, pumps the chlorophyll downwards an order of magnitude faster than gravitational sinking alone. Particle tracking using the ocean reanalysis fields reveals that a substantial portion of the chlorophyll away from the front is advected off of the northeast Chukchi shelf before reaching the bottom. This highlights the importance of the frontal subduction process for delivering carbon to the sea floor.
Keywords:

Chlorophyll Phytoplankton
Source:

Journal of Geophysical Research: Oceans, 129, e2024JC021465
DOI:

https://doi.org/10.1029/2024JC021465
Format:

PDF
Document Type:

Journal Article
Funding:

Grant no. NA19OAR4320074
Place as Subject:

Chukchi Sea
License:

https://creativecommons.org/licenses/by-nc-nd/4.0/
Rights Information:

CC BY-NC-ND
Compliance:

Submitted
Main Document Checksum:

urn:sha-512:b4434c0f637b8626aa6b169335d696b2ae382ea90a40ec1469eccb261a4caac06a3dabc48e193bbbdfbfd66d3efb6b110bd4d5090288f2ec6a408c49e3276985
Download URL:

https://repository.library.noaa.gov/view/noaa/72314/noaa_72314_DS1.pdf
File Type:

[PDF - 7.97 MB ]

Supplemental media

Download docx

ON THIS PAGE

Details Supporting Files

The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners. As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.