We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Continental and Sea Ice Iron Sources Fertilize the Southern Ocean in Synergy.
- Authors
Person, Renaud; Vancoppenolle, Martin; Aumont, Olivier; Malsang, Manon
- Abstract
Iron release from melting continental and sea ice is deemed important for phytoplankton, the growth of which is iron‐limited in the Southern Ocean. Both sources are generally considered separately, yet their effects on the biological carbon pump could interact. Using a global ocean‐sea‐ice‐biogeochemical model with a representation of both continental and sea ice iron sources, we find them to have an overall additive effect on phytoplankton activity, increasing carbon export by +13.9% of the Southern Ocean total, with continental ice contributing +4.5% and sea ice +8.0%. The +1.4% residual is due to a coupled fertilization effect: When the iron source from continental ice is activated, iron in sea ice increases by 16%, so does iron transport toward low production areas. Overall, this increases phytoplankton activity: Fertilization is more efficient where sea ice melts than at locations of initial iron release by continental ice. Plain Language Summary: Phytoplankton refers to micro‐algae growing and drifting within seawater. Most living organisms in the ocean ultimately depend on phytoplankton. When sinking, organic matter produced by phytoplankton sequesters large amounts of carbon in the deep ocean. The Southern Ocean is a key area for these processes. There, the iron dissolved in seawater, available in tiny amounts, exerts a strong constraint on phytoplankton growth. Melting ice in the Southern Ocean is a key iron source to surface waters, which fosters phytoplankton growth, yet how much and how efficiently is the subject of ongoing research. Here we present numerical simulations of ocean physics, ice, and marine plankton, representing iron release from melting ice. We find more plankton and stronger carbon sequestration in the ocean where ice releases more iron. These locations also correspond to where phytoplankton are seen from space. A unique aspect of our simulations is the accounting for ice of two different origins (continental and sea ice). We find that both ice forms tend to release iron at similar locations. We also find their fertilization effects to reinforce each other. Indeed, sea ice stores iron released by continental ice and moves it where it is more efficiently assimilated by phytoplankton. Key Points: Stronger and more realistic Southern Ocean phytoplankton activity by modeling iron release from melting continental and sea iceContinental and sea ice iron sources have an overall additive effect on the biological carbon pump strengthThe fertilization effects of the sea‐ice iron source are larger when the continental‐ice iron source is activated
- Subjects
SEA ice; IRON; OCEAN; MARINE plankton; CARBON sequestration; ORGANIC compounds
- Publication
Geophysical Research Letters, 2021, Vol 48, Issue 23, p1
- ISSN
0094-8276
- Publication type
Article
- DOI
10.1029/2021GL094761