Application of Data Assimilation to a Peatland Methane Study

Data assimilation is widely used in terrestrial ecosystem studies. This chapter illustrates the use of data assimilation with a site-level study to project peatland methane (CH₄) emission in response to warming. Wetland CH₄ emissions comprise one third of the global CH₄ source and remain the largest source of uncertainty in the global budget. Wetland CH₄ emission estimated by process-based models (bottom-up) are used as the prior information for atmospheric inversion estimates (top-down). It is thus important to constrain process-based models with in situ observations to improve both the bottom-up and top-down estimates. We give a brief background of methane modeling and then show the application of data assimilation in the methane model in seven steps.