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Climate warming affects the development and distribution of sea ice, but at present the evidence of polar ecosystem feedbacks on climate through changes in the atmosphere is sparse. By means of synergistic atmospheric and oceanic measurements in the Southern Ocean near Antarctica, we present evidence that the microbiota of sea ice and sea ice-influenced ocean are a previously unknown significant source of atmospheric organic nitrogen, including low molecular weight alkyl-amines. Given the keystone role of nitrogen compounds in aerosol formation, growth and neutralization, our findings call for greater chemical and source diversity in the modelling efforts linking the marine ecosystem to aerosol-mediated climate effects in the Southern Ocean.
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http://dx.doi.org/10.1038/s41598-017-06188-x | DOI Listing |
Environ Microbiol Rep
October 2025
Department of Biology, Marine Biology Section, University of Copenhagen, Helsingør, Denmark.
Due to climate change, sea ice more commonly retreats over the shelf breaks in the Arctic Ocean, impacting sea ice-pelagic-benthic coupling in the deeper basins. Nitrogen fixation (the reduction of dinitrogen gas to bioavailable ammonia by microorganisms called diazotrophs) is reported from Arctic shelf sediments but is unknown from the Arctic deep sea. We sampled five locations of deep-sea (900-1500 m) surface sediments in the central ice-covered Arctic Ocean to measure potential nitrogen fixation through long-term (> 280 days) stable-isotope (N) incubations and to study diazotroph community composition through amplicon sequencing of the functional marker gene nifH.
View Article and Find Full Text PDFBiogeochemistry
September 2025
Department of Earth Sciences, Uppsala University, Uppsala, 75236 Sweden.
Unlabelled: Ocean surface gravity waves facilitate gas exchanges primarily in two ways: (1) the formation of bubbles during wave breaking increases the surface area available for gas exchange, promoting CO transfer, and (2) wave-current interaction processes alter the sea surface partial pressure of CO and gas solubility, consequently affecting the CO flux. This study tests these influences using a global ocean-ice-biogeochemistry model under preindustrial conditions. The simulation results indicate that both wave-current interaction processes and the sea-state-dependent gas transfer scheme-which explicitly accounts for bubble-mediated gas transfer velocity-influence the air-sea CO flux, with substantial spatial and seasonal variations.
View Article and Find Full Text PDFMar Pollut Bull
September 2025
Korea Polar Research Institute, 26 Songdomirae-ro, Incheon 21990, Republic of Korea.
Here we present the study of 48 new dinoflagellate cyst assemblages from the west Antarctic shelf sediments on a wide longitudinal scale, with a greater representation of ice-proximal sites, and provide a comprehensive overview of their distributional patterns and multiple environmental forcing factors. We find a strong spatial heterogeneity in the dinoflagellate cyst distribution patterns; 1) the northern Antarctic Peninsula region is dominated by Islandinium? minutum, Selenopemphix antarctica and Brigantedinium spp. in association with meltwater-induced stratification and high diatom productivity, 2) the Bellingshausen-Amundsen Seas is dominated by Gymnodinium microreticulatum and Selenopemphix sp.
View Article and Find Full Text PDFCamb Prism Coast Futur
November 2024
City of Philadelphia, Offices of Sustainability and Climate Resilience, 1515 Arch Street, Philadelphia, PA 19102, USA.
We synthesize sea-level science developments, priorities and practitioner needs at the end of the 10-year World Climate Research Program Grand Challenge 'Regional Sea-Level Change and Coastal Impacts'. Sea-level science and associated climate services have progressed but are unevenly distributed. There remains deep uncertainty concerning high-end and long-term sea-level projections due to indeterminate emissions, the ice sheet response and other climate tipping points.
View Article and Find Full Text PDFJ Environ Qual
August 2025
US EPA, Office of Policy, National Center for Environmental Economics, Washington, USA.
Eutrophication enhances emissions of greenhouse gases (GHGs) from surface waters. Policies designed to ameliorate eutrophication by limiting nutrient loadings to surface waters can reduce these GHG emissions and, in turn, reduce future climate damages (e.g.
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