Document Type
Article
Publication Date
2026
DOI
10.5194/bg-23-665-2026
Publication Title
Biogeosciences
Volume
23
Issue
2
Pages
665-682
Abstract
The Amundsen Sea Embayment (ASE) experiences both the highest ice shelf melt rates and the highest biological productivity in West Antarctica. Using 19 years of satellite data and modelling output, we investigate the long-term influence of environmental factors on the phytoplankton bloom in the Amundsen Sea (ASP) and Pine Island (PIP) polynyas. We test the prevailing hypothesis that changes in ice shelf melt rate could drive interannual variability in the polynyas' surface chlorophyll-a (chl a) and Net Primary Productivity (NPP). We find that the interannual variability and long-term change in glacial meltwater may play an important role in chl a variance in the ASP, but not for NPP. Glacial meltwater does not explain the variability in neither chl a or NPP in the PIP, where light and temperature are the main drivers. We attribute this to potentially greater amount of iron-enriched meltwater brought to the surface by the meltwater pump downstream of the PIP, and the coastal ocean circulation accumulating and transporting iron towards the ASP.
Rights
© The Authors 2026.
This work is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0) License.
Data Availability
Article states: "Bathymetry data (Amante and Eakins, 2009) was taken from the NOAA website (http://www.ngdc.noaa.gov/mgg/global/global.html, last access: 19 August 2025). Mixed-layer depth (ECCO Consortium et al., 2021) can be accessed here: https://podaac.jpl.nasa.gov/dataset/ECCO_L4_MIXED_LAYER_DEPTH_05DEG_MONTHLY_V4R4 (last access: 19 August 2025). Satellite surface chlorophyll-a and photosynthetically available radiation were downloaded from https://www.globcolour.info/ (last access: 10 February 2025). Sea surface temperature (Huang et al., 2021) can be found here https://psl.noaa.gov/data/gridded/data.noaa.oisst.v2.highres.html. Wind re-analysis data (Hersbach et al., 2020) are available at https://cds.climate.copernicus.eu/datasets/reanalysis-era5-single-levels-monthly-means?tab=download (last access: 10 February 2025). Sea-ice concentration (Cavalieri et al., 1996) was obtained from https://nsidc.org/data (last access: 10 February 2025) and Net Primary productivity (Behrenfeld and Falkowski, 1997) was downloaded from http://sites.science.oregonstate.edu/ocean.productivity/index.php (last access: 10 February 2025). Circumpolar surface model output from Dinniman et al (2020) can be found at https://www.bco-dmo.org/dataset/782848 (last access: 10 February 2025). The Amundsen Sea Low index (Hosking et al., 2016) data are available at http://scotthosking.com/asl_index (last access: 10 February 2025)."
Original Publication Citation
Liniger, G., Lannuzel, D., Moreau, S., Dinniman, M. S., & Strutton, P. G. (2026). Drivers of phytoplankton bloom interannual variability in the Amundsen and Pine Island polynyas. Biogeosciences, 23(2), 665-682. https://doi.org/10.5194/bg-23-665-2026
Repository Citation
Liniger, Guillaume; Lannuzel, Delphine; Moreau, Sébastien; Dinniman, Michael S.; and Stutton, Peter G., "Drivers of Phytoplankton Bloom Interannual Variability in the Amundsen and Pine Island Polynyas" (2026). CCPO Publications. 411.
https://digitalcommons.odu.edu/ccpo_pubs/411
ORCID
0000-0001-7519-9278 (Dinniman)
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