Simulating natural carbon sequestration in the Southern Ocean: on uncertainties associated with eddy parameterizations and iron deposition
The Southern Ocean is a major sink for anthropogenic carbon. Yet, there is no quantitative consensus about how this sink will change when surface winds increase (as they are anticipated to do). Among the tools employed to quantify carbon uptake are global coupled ocean-circulation–biogeochemical mod...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-03-01
|
| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/14/1561/2017/bg-14-1561-2017.pdf |
| Summary: | The Southern Ocean is a major sink for anthropogenic carbon. Yet, there is no
quantitative consensus about how this sink will change when surface winds
increase (as they are anticipated to do). Among the tools employed to
quantify carbon uptake are global coupled ocean-circulation–biogeochemical
models. Because of computational limitations these models still fail to
resolve potentially important spatial scales. Instead, processes on these
scales are parameterized. There is concern that deficiencies in these
so-called <i>eddy parameterizations</i> might imprint incorrect sensitivities of
projected oceanic carbon uptake. Here, we compare natural carbon uptake in
the Southern Ocean simulated with contemporary eddy parameterizations. We
find that very differing parameterizations yield surprisingly similar oceanic
carbon in response to strengthening winds. In contrast, we find (in an
additional simulation) that the carbon uptake does differ substantially when
the supply of bioavailable iron is altered within its envelope of
uncertainty. We conclude that a more comprehensive understanding of
bioavailable iron dynamics will substantially reduce the uncertainty of
model-based projections of oceanic carbon uptake. |
|---|---|
| ISSN: | 1726-4170 1726-4189 |