Publication Date:
2022-05-25
Description:
Author Posting. © American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 26 (2013): 9291–9312, doi:10.1175/JCLI-D-12-00566.1.
Description:
The authors compare Community Earth System Model results to marine observations for the 1990s and examine climate change impacts on biogeochemistry at the end of the twenty-first century under two future scenarios (Representative Concentration Pathways RCP4.5 and RCP8.5). Late-twentieth-century seasonally varying mixed layer depths are generally within 10 m of observations, with a Southern Ocean shallow bias. Surface nutrient and chlorophyll concentrations exhibit positive biases at low latitudes and negative biases at high latitudes. The volume of the oxygen minimum zones is overestimated.
The impacts of climate change on biogeochemistry have similar spatial patterns under RCP4.5 and RCP8.5, but perturbation magnitudes are larger under RCP8.5. Increasing stratification leads to weaker nutrient entrainment and decreased primary and export production (〉30% over large areas). The global-scale decreases in primary and export production scale linearly with the increases in mean sea surface temperature. There are production increases in the high nitrate, low chlorophyll (HNLC) regions, driven by lateral iron inputs from adjacent areas. The increased HNLC export partially compensates for the reductions in non-HNLC waters (~25% offset). Stabilizing greenhouse gas emissions and climate by the end of this century (as in RCP4.5) will minimize the changes to nutrient cycling and primary production in the oceans. In contrast, continued increasing emission of CO2 (as in RCP8.5) will lead to reduced productivity and significant modifications to ocean circulation and biogeochemistry by the end of this century, with more drastic changes beyond the year 2100 as the climate continues to rapidly warm.
Description:
The CESM project is supported by the National
Science Foundation and the Office of Science
(BER) of the U.S. Department of Energy. S.C.D. acknowledges
support of Collaborative Research: Improved Regional
and Decadal Predictions of the Carbon Cycle (NSF
AGS-1048827). This work was supported by NSF grants
(ARC-0902045 and AGS-1021776 to Moore and AGS-
1048890 to Moore, Lindsay, and Doney).
Description:
2014-06-01
Keywords:
Climate prediction
;
Forecast verification/skill
;
Climate models
;
Ecological models
;
Model evaluation/performance
;
Ocean models
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
Permalink
