Towards source estimation: Modeling Methane columns over Europe

Abstract

Methane gas is the second-largest contributor to the greenhouse effect. Under the 2015 Paris Agreement, worldwide methane emissions are to be reduced. To monitor these reductions it is important to be able to identify sources of methane.

Bottom-up emission inventories estimate methane sources from activities and emission factors. By implementing these emissions in a Chemical Transport Model (CTM), methane concentration can be predicted and compared with observations.

The aim of this study is to work towards the use of LOTOS-EUROS (CTM) and TROPOMI satellite measurements to verify European emission inventories.

Study objectives are getting insight in methane emission inventories and evaluating the model sensitivity and performance. The latter will be achieved by comparing the model simulations with methane observations. Additionally, we will take a first look at the TROPOMI data and discus some retrieval difficulties.

This study finds that LOTOS-EUROS is able to simulate the methane volume mixing ratios in the right order magnitude. However, there seems to be an incorrect VMR gradient simulated in the stratosphere.

Preliminary results from TROPOMI suggest that strong source regions can be quantified. Besides, they indicate that LOTOS-EUROS simulates locally smaller enhancements than TROPOMI measures. More TROPOMI data is needed to be conclusive on this.