When comparing the IASI CH4 product with a high resolution profile (aircraft profiles, model data..), the sensitivity of the (low resolution) IASI CH4 profiles needs to be taken into account.

This can be done by smoothing the high resolution profile with the IASI CH4 averaging kernel :



Eq xsm   :  the smoothed (aircraft or model) profile

Eq xsa :  the IASI CH4 a priori profile

Eq A   :  the IASI CH4 averaging kernel

Eq x   :  the high resolution (aircraft or model) profile

Note, the averaging kernel is given in vmr/vmr units.




The IASI CH4 product is developed and distributed by the Infrared Team of BIRA-IASB.

Note: this dataset is generated as part of the ESA GHG-CCI project and is still under validation.

The IASI CH4 profiles are delivered in HDF5 format. Daily daytime and nighttime observations are provided in separate files. The HDF files contain CH4 profiles, the retrieval error, the a CH4 priori profiles and averaging kernels. Each individual file is typically 200-260 MB. If your data request is large, please contact the data manager (This email address is being protected from spambots. You need JavaScript enabled to view it.)

The retrievals are performed between 60°S and 70°N.