Research 331: IMPLiCIt: IMProving inversion modeL Capability in Ireland

Authors: Colin O’Dowd, Damien Martin and Dèlia Arnold

Summary: The IMPLiCIt project aims to develop a combined measurement and modelling system to verify methane sources over Ireland and regions affecting the Irish domain, and to improve Irish national capacities to estimate and verify national methane and other greenhouse gas (GHG) emissions inventories.

Published: 2020

ISBN: 978-1-84095-923-9

Pages: 65

Filesize: 7,226KB

Format: pdf

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Project Highlights

Watch the IMPLiCIt project highlights video 

The IMPLICIT project builds national capacity in the area of climate change and, in particular, extends our understanding of national greenhouse gas emissions using in situ observations and state-of-the-art computer modelling to produce top-down national estimates and verification of bottom-up traditional estimates. 

Identifying Pressures 

Irish greenhouse gas emissions are internationally reported and are based on statistical activity data comprising source-specific and country-specific emission factors. For methane and nitrous oxide, however, such “bottom-up” emission inventories have a substantial degree of uncertainty, mainly because of variability of emission factors and the influence of natural sources and processes. This project aims to constrain these uncertainties with a complementary top-down approach using inverse modelling techniques and observational data from Ireland’s climate change monitoring network. 

Informing Policy 

Ireland’s 2020 target is to achieve a 20% reduction in non-Emission Trading Scheme (non-ETS) sector emissions (i.e. agriculture, transport, the built environment, waste and non-energy-intensive industry) relative to 2005 levels, with annual limits set for each year over the period 2013–2020. This project informs the efficacy of proposed mitigation strategies by producing annual mapped national emission estimates for greenhouse gases, with a special focus on methane. 

Developing Solutions 

A solution to the pressing issue of greenhouse gases is to develop national capability in terms of inversion model capability and this project seeks to deliver the first steps in this development. The FLEXINVERT modelling system can be deployed to produce inversions for any species for which atmospheric loss (if any) can be described as a linear process, such as radioactive decay, dry and wet deposition, and oxidative chemistry. Furthermore, the modelling framework described can be used on a range of scales, including continental, regional and local, and, as well as methane, can be further utilised for nitrous oxide, carbon dioxide and other atmospheric species, offering the
possibility of constraining a range of emissions estimates, given suitable measurements.