HR: 1340h
AN: B53B-1176    [Abstracts]
TI: Reconstruction Of Air-Sea Fluxes And Meridional Transport Rates Of Anthropogenic Carbon With An Ensemble Kalman Filter Data Assimilation
AU: * Gerber, M
EM: mgerber@climate.unibe.ch
AF: Climate and Environmental Physics, Physics Institute, University of Bern, Siedlerstrasse 5, Bern, BE 3012, Switzerland
AU: Joos, F
EM: joos@climate.unibe.ch
AF: Climate and Environmental Physics, Physics Institute, University of Bern, Siedlerstrasse 5, Bern, BE 3012, Switzerland
AU: Vazquez Rodriguez, M
EM: mvazquez@iim.csic.es
AF: Department of Oceanography Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, Vigo, 36208, Spain
AB: Regional air-sea fluxes and meridional transport of anthropogenic carbon are inferred by assimilating anthropogenic carbon concentrations within the ocean from different data-based reconstructions. An inverse, Ensemble Kalman Filter method with the Bern3D ocean model is applied. The Bern3D model (Müller et al., 2006) is a computationally-efficient, 3-dimensional coarse resolution ocean model. The Ensemble Kalman Filter (Evenson, 2003) is suited for the assimilation of spatially and temporally varying data into a range of models, for model tuning or for model initialization.
Regional fluxes through the air-sea interface and meridional transport rates in the ocean are determined by minimizing deviations between the distributions of anthropogenic carbon from the GLODAP database (Key et al., 2004) and from the Bern3D ocean model in the Ensemble Kalman Filtering optimzation. The resulting anthropogenic carbon fluxes are in agreement with those from another ocean inversion study using the same GLODAP data (Mikaloff Fletcher et al., 2006).
Transport uncertainties are addressed by utilizing different configuration of the Bern3D model. The inferred transport uncertainties are comparable in magnitude to the uncertainties obtained by Mikaloff Fletcher et al.
The fields of anthropogenic carbon reconstructed with six different reconstruction methods: CFC-shortcut (Thomas et al., 2001), C-star (Gruber et al. 1996), IPSL (Lo Monaco et al., 2005), PHI-CT (Vazquez Rodriguez et al, submitted), TrOCA (Touratier et al., 2004), and TTD (Waugh et al., 2006) from four sections in the Atlantic are assimilated individually to investigate the influence of data uncertainties on the inferred fluxes. Deviations in the inferred fluxes from the different reconstruction methods are comparable or even larger than uncertainties arising from model transport uncertainties. For example, anthropogenic carbon uptake is more than twice as large for the IPSL reconstruction than for the PHI-CT reconstruction in the subpolar and tropical Atlantic.
DE: 0428 Carbon cycling (4806)
DE: 0430 Computational methods and data processing
DE: 0466 Modeling
SC: Biogeosciences [B]
MN: 2007 Fall Meeting