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| Titel |
A multi-model study on the Southern Ocean CO2 uptake and the role of the biological carbon pump in the 21st century |
| VerfasserIn |
Judith Hauck, Christoph Völker, MAREMIP Team |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250112068
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| Publikation (Nr.) |
 EGU/EGU2015-12225.pdf |
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| Zusammenfassung |
| The Southern Ocean is one of the key regions for global carbon uptake and it is under
discussion how physical changes will alter its CO2 balance both directly and indirectly
through changes in biological production.
Here we analyse a suite of eight RCP8.5 model simulations until 2100 from the
MAREMIP and CMIP5 model intercomparison projects on changes in export production and
CO2 uptake. We explore how the counter-acting effects of stronger winds ("SAM signal", less
stratification) and global warming (more stratification) affect CO2 fluxes in different models
and different regions of the Southern Ocean.
The models simulate a broad range of responses with no agreement on the dominance of
the SAM or global warming signal or on nutrient or light as the dominant drivers for changes
in export production. There is agreement on an increase in export production south of 58°S
and on a nutrient-driven decrease of export production in the region 30-44°S (global warming
signal). Based on a box-model, we can identify the most important drivers for the
future CO2 uptake in the Southern Ocean where the pure increase of atmospheric
CO2 has the largest effect, followed by the enhanced biological production and the
larger effect of biological production on CO2 uptake at higher Revelle factor. The
enhanced upwelling of carbon-rich deep water, and the effects of warming on the
CO2 solubility and faster gas-exchange at higher wind-speeds are less important. |
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