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Constraining DALEC v2 using multiple data streams and ecological constraints: analysis and application.

Delahaies, Sylvain, Roulstone, Ian and Nichols, N (2017) Constraining DALEC v2 using multiple data streams and ecological constraints: analysis and application. Geoscientific Model Development, 10 (7). pp. 2635-2650.

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We use a variational method to assimilate multiple data streams into the terrestrial ecosystem carbon cycle model DALECv2. Ecological and dynamical constraints have recently been introduced to constrain unresolved components of this otherwise ill-posed problem. Here we recast these constraints as a multivariate Gaussian distribution to incorporate them into the variational framework and we demonstrate their benefit through a linear analysis. 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 ill-posedness and evaluate regularisation strategies.We then study the non linear problem with an application to real data. Finally, we propose a modification to the model: introducing a spin-up period provides us with a built-in formulation of some ecological constraints which facilitates the variational approach.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Mathematics
Authors :
Nichols, N
Date : 10 July 2017
DOI : 10.5194/gmd-2017-22, 2017
Copyright Disclaimer : Copyright 2017 The Author(s). Published by European Geosciences Union and distributed under a Creative Commons Attribution 3.0 License. Anyone can use the article freely under the stipulation that the original authors are given credit and the appropriate citation details are mentioned.
Depositing User : Melanie Hughes
Date Deposited : 30 May 2017 10:57
Last Modified : 16 Jan 2019 18:52

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