A joint effort to deliver satellite retrieved atmospheric CH4 concentrations for surface flux inversions
The ensemble median algorithm EMMA CH4


Since long time, climate modellers use ensemble approaches to calculate the ensemble median and to estimate uncertainties of climate projections where no ground-truth is known. Following this idea, the ensemble median algorithm EMMA CH4 composes level 2 data of five GOSAT retrievals developed by NIES, SRON, and the University of Leicester. EMMA CH4 determines in 10x10 degree grid boxes monthly averages and selects the level 2 data of the median algorithm.


EMMA CH4, University of Bremen
Max Reuter (maximilian.reuter at iup.physik.uni-bremen.de)
Institute of Environmental Physics (IUP)
University of Bremen, FB1
Otto-Hahn-Allee 1
D-28334 Bremen
Phone: +49 (421) 218 62085
FAX: +49 (421) 218 4555

WFMD retrieval, University of Bremen
Oliver Schneising (oliver.schneising at iup.physik.uni-bremen.de)

NIES operational retrieval
Yoshida Yukio (yoshida.yukio at nies.go.jp)

NIES PPDF-S retrieval
Andrey Bril (andrey.bril at gmail.com)

RemoTeC full physics (FP) and proxy (PR) retrieval, SRON, KIT
Andre Butz (andre.butz at dlr.de)
Otto Hasekamp (o.p.hasekamp at sron.nl)

UoL full physics (FP) and proxy (PR) retrieval, University of Leicester
Hartmut Bösch (hb100 at leicester.ac.uk)

+ Literature

+ Image Galery

+ Version History

Data Access

The data access is password-restricted. Please use the following form to obtain username and password.





Please tell us in a few words (>3) what you plan with the data:

I agree with the conditions of use:

After registration, please use the following link to access the data archive:

Till now, the EMMA CH4 data set covers the period 01/2003-12/2018.

The data-format is NCDF.

Condition of Use

When using EMMA CH4 data, you agree ...

... to inform us prior to any publication where EMMA CH4 data products are planned to be used.

... to offer us co-authorship for any planned peer-reviewed publication based on EMMA CH4 data products. (For non peer-reviewed publications it is sufficient if you add an appropriate acknowledgement.)

... not to distribute the EMMA CH4 data products to any third party. The only exception being colleagues working in your institute (in this case you agree to inform them about the conditions listed here and that they also have to accept these conditions).


EMMA CH4 is in part funded by ESA/ESRIN (GHG CCI-II), EU C3S, and the state and the University of Bremen as well as participating institues and funding organizations.