Publication Date:
2022-05-25
Description:
© Authors, 2010. This work is distributed under
the Creative Commons Attribution 3.0 License. The definitive version was published in Biogeosciences 7 (2010): 979-1005, doi: 10.5194/bg-7-979-2010
Description:
Changes in marine net primary productivity (PP) and export of particulate organic carbon (EP) are projected over the 21st century with four global coupled carbon cycle-climate models. These include representations of marine ecosystems and the carbon cycle of different structure and complexity. All four models show a decrease in global mean PP and EP between 2 and 20% by 2100 relative to preindustrial conditions, for the SRES A2 emission scenario. Two different regimes for productivity changes are consistently identified in all models. The first chain of mechanisms is dominant in the low- and mid-latitude ocean and in the North Atlantic: reduced input of macro-nutrients into the euphotic zone related to enhanced stratification, reduced mixed layer depth, and slowed circulation causes a decrease in macro-nutrient concentrations and in PP and EP. The second regime is projected for parts of the Southern Ocean: an alleviation of light and/or temperature limitation leads to an increase in PP and EP as productivity is fueled by a sustained nutrient input. A region of disagreement among the models is the Arctic, where three models project an increase in PP while one model projects a decrease. Projected changes in seasonal and interannual variability are modest in most regions. Regional model skill metrics are proposed to generate multi-model mean fields that show an improved skill in representing observation-based estimates compared to a simple multi-model average. Model results are compared to recent productivity projections with three different algorithms, usually applied to infer net primary production from satellite observations.
Description:
This work was funded by the European
Union projects CARBOOCEAN (511176-2) and EUROCEANS
(511106-2) and is a contribution to the “European Project on
Ocean Acidification” (EPOCA) which received funding from
the European Community’s Seventh Framework Programme
(FP7/2007–2013) under grant agreement no. 211384. Additional
support was received from the Swiss National Science Foundation.
SCD acknowledges support from the NASA Ocean Biology and
Biogeochemistry Program (NNX07AL80G). LB aknowledges support
from the EU Project MEECE (Marine Ecosystem Evolution in
a Changing Environnement, grant agreement 212085).
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
