Volumes and Issues  Contents of Issue 3  
Biogeosciences Discuss., 8, 4239-4280, 2011
www.biogeosciences-discuss.net/8/4239/2011/
doi:10.5194/bgd-8-4239-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.


Climate impacts on the structures of the North Pacific air-sea CO2 flux variability

V. Valsala1, S. Maksyutov1, M. Telszewski1, S.-I. Nakaoka1, Y. Nojiri1, M. Ikeda2, and R. Murtugudde3
1CGER, National Institute for Environmental Studies (NIES), Tsukuba, Japan
2Retired from EES, Hokkaido University, Japan
3ESSIC, University of Maryland, College Park, MD, USA

Abstract. Some dominant spatial and temporal structures of the North Pacific air-sea CO2 fluxes in response to the Pacific Decadal Oscillation (PDO) are identified in four data products from four independent sources: an assimilated CO2 flux product, two forward model solutions, and a gridded pCO2 dataset constructed with a neural network approach. The interannual variability of CO2 flux is found to be an order of magnitude weaker compared to the seasonal cycle of CO2 flux in the North Pacific. A statistical approach is employed to quantify the signal-to-noise ratio in the reconstructed dataset to delineate the representativity errors. The dominant variability with a signal-to-noise ratio above one is identified and its correlations with PDO are examined. A tentative four-box structure in the North Pacific air-sea CO2 flux variability linked to PDO emerges in which two positively correlated boxes are oriented in the northwest and southeast directions and contrarily, the negatively correlated boxes are oriented in the northeast and southwest directions. This pattern is verified with the CO2 and pCO2 from four products and its relations to the interannual El NiƱo-Southern Oscillation (ENSO) and lower-frequency PDO are separately identified. A combined EOF analysis between air-sea CO2 flux and key variables representing ocean-atmosphere interactions is carried out to elicit robust oscillations in the North Pacific CO2 flux in response to the PDO. The proposed spatial and temporal structures of the North Pacific CO2 fluxes are insightful since they separate the secular trends of the surface ocean carbon from the interannual variability. The regional characterization of the North Pacific in terms of PDO and CO2 flux variability is also instructive for determining the homogeneous oceanic domains for the Regional Carbon Cycle and Assessment Processes (RECCAP).

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Citation: Valsala, V., Maksyutov, S., Telszewski, M., Nakaoka, S.-I., Nojiri, Y., Ikeda, M., and Murtugudde, R.: Climate impacts on the structures of the North Pacific air-sea CO2 flux variability, Biogeosciences Discuss., 8, 4239-4280, doi:10.5194/bgd-8-4239-2011, 2011.   Bibtex   EndNote   Reference Manager    XML
 

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