On the observability of turbulent transport rates by Argo: supporting evidence from an inversion experiment
Name
Forget-2015-On the observability.pdf
Size
2.24 MB
Format
Adobe PDF
Checksum (MD5)
8dd313d3245a7f6d9ce07d5d36265009
Author(s)
Ferreira, D.
Forget, Gael
Liang, Xinfeng
Date Issued
October 2015
Journal
Ocean Science
Publisher
Copernicus GmbH
Citation
Forget, G., D. Ferreira, and X. Liang. “On the Observability of Turbulent Transport Rates by Argo: Supporting Evidence from an Inversion Experiment.” Ocean Science 11, no. 5 (2015): 839–853.
Version
Final published version
Abstract
Although estimation of turbulent transport parameters using inverse methods is not new, there is little evaluation of the method in the literature. Here, it is shown that extended observation of the broad-scale hydrography by Argo provides a path to improved estimates of regional turbulent transport rates. Results from a 20-year ocean state estimate produced with the ECCO v4 (Estimating the Circulation and Climate of the Ocean, version 4) non-linear inverse modeling framework provide supporting evidence. Turbulent transport parameter maps are estimated under the constraints of fitting the extensive collection of Argo profiles collected through 2011. The adjusted parameters dramatically reduce misfits to in situ profiles as compared with earlier ECCO solutions. They also yield a clear reduction in the model drift away from observations over multi-century-long simulations, both for assimilated variables (temperature and salinity) and independent variables (biogeochemical tracers). Despite the minimal constraints imposed specifically on the estimated parameters, their geography is physically plausible and exhibits close connections with the upper-ocean stratification as observed by Argo. The estimated parameter adjustments furthermore have first-order impacts on upper-ocean stratification and mixed layer depths over 20 years. These results identify the constraint of fitting Argo profiles as an effective observational basis for regional turbulent transport rate inversions. Uncertainties and further improvements of the method are discussed.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.5194/os-11-839-2015
