Back to overview

Retrieval and validation of MetOp/IASI methane

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author De Wachter Evelyn, Kumps Nicolas, Vandaele Ann Carine, Langerock Bavo, De Mazière Martine,
Project Beitrag an den Unterhalt und Betrieb der Hochalpinen Forschungsstationen Jungfraujoch und Gornergrat, 2015-2017
Show all

Original article (peer-reviewed)

Journal Atmospheric Measurement Techniques
Volume (Issue) 10(12)
Page(s) 4623 - 4638
Title of proceedings Atmospheric Measurement Techniques
DOI 10.5194/amt-10-4623-2017

Open Access

Type of Open Access Publisher (Gold Open Access)


A new IASI methane product developed at the Royal Belgian Institute for Space Aeronomy (BIRA-IASB) is presented. The retrievals are performed with the ASIMUT-ALVL software based on the optimal estimation method (OEM). This paper gives an overview of the forward model and retrieval concept. The usefulness of reconstructed principal component compressed (PCC) radiances is highlighted. The information content study carried out in this paper shows that most IASI pixels contain between 0.9 and 1.6 independent pieces of information about the vertical distribution of CH 4 , with a good sensitivity in the mid- to upper troposphere. A detailed error analysis was performed. The total uncertainty is estimated to be 3.73 % for a CH 4 partial column between 4 and 17 km. An extended validation with ground-based CH 4 observations at 10 locations was carried out. IASI CH 4 partial columns are found to correlate well with the ground-based data for 6 out of the 10 Fourier transform infrared (FTIR) stations with correlation coefficients between 0.60 and 0.84. Relative mean differences between IASI and FTIR CH 4 range between −2.31 and 4.04 % and are within the systematic uncertainty. For 6 out of the 10 stations the relative mean differences are smaller than ±1 %. The standard deviation of the difference lies between 1.76 and 2.97 % for all the stations.