Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application
We use a variational method to assimilate multiple data streams into the terrestrial ecosystem carbon cycle model DALECv2 (Data Assimilation Linked Ecosystem Carbon). Ecological and dynamical constraints have recently been introduced to constrain unresolved components of this otherwise illposed problem. We recast these constraints as a multivariate Gaussian distribution to incorporate them into the variational framework and we demonstrate their advantage through a linear analysis. By using an adjoint method we study a linear approximation of the inverse problem: firstly we perform a sensitivity analysis of the different outputs under consideration, and secondly we use the concept of resolution matrices to diagnose the nature of the illposedness and evaluate regularisation strategies. We then study the nonlinear problem with an application to real data. Finally, we propose a modification to the model: introducing a spinup period provides us with a builtin formulation of some ecological constraints which facilitates the variational approach.
 Authors:

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 Univ. of Surrey, Guildford (United Kingdom). Dept. of Mathematics
 Univ. of Reading, (United Kingdom). Dept. of Mathematics
 Publication Date:
 Grant/Contract Number:
 FG0207ER64371
 Type:
 Accepted Manuscript
 Journal Name:
 Geoscientific Model Development (Online)
 Additional Journal Information:
 Journal Name: Geoscientific Model Development (Online); Journal Volume: 10; Journal Issue: 7; Journal ID: ISSN 19919603
 Publisher:
 European Geosciences Union
 Research Org:
 Univ. of Indiana, Bloomington, IN (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC23)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 58 GEOSCIENCES
 OSTI Identifier:
 1392991
Delahaies, Sylvain, Roulstone, Ian, and Nichols, Nancy. Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application. United States: N. p.,
Web. doi:10.5194/gmd1026352017.
Delahaies, Sylvain, Roulstone, Ian, & Nichols, Nancy. Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application. United States. doi:10.5194/gmd1026352017.
Delahaies, Sylvain, Roulstone, Ian, and Nichols, Nancy. 2017.
"Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application". United States.
doi:10.5194/gmd1026352017. https://www.osti.gov/servlets/purl/1392991.
@article{osti_1392991,
title = {Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application},
author = {Delahaies, Sylvain and Roulstone, Ian and Nichols, Nancy},
abstractNote = {We use a variational method to assimilate multiple data streams into the terrestrial ecosystem carbon cycle model DALECv2 (Data Assimilation Linked Ecosystem Carbon). Ecological and dynamical constraints have recently been introduced to constrain unresolved components of this otherwise illposed problem. We recast these constraints as a multivariate Gaussian distribution to incorporate them into the variational framework and we demonstrate their advantage through a linear analysis. By using an adjoint method we study a linear approximation of the inverse problem: firstly we perform a sensitivity analysis of the different outputs under consideration, and secondly we use the concept of resolution matrices to diagnose the nature of the illposedness and evaluate regularisation strategies. We then study the nonlinear problem with an application to real data. Finally, we propose a modification to the model: introducing a spinup period provides us with a builtin formulation of some ecological constraints which facilitates the variational approach.},
doi = {10.5194/gmd1026352017},
journal = {Geoscientific Model Development (Online)},
number = 7,
volume = 10,
place = {United States},
year = {2017},
month = {7}
}