The IASI spectrally resolved Outgoing Longwave Radiation product (IASI OLR) is a monthly (L3), 2 x 2 degree global dataset of spectral OLR derived from the clear-sky IASI satellite radiance measurements. 

The algorithm for the conversion of the spectra to the OLR is detailed in Whitburn et al. (2020, Journal of Climate). 

The method was applied to reprocessed IASI L1C data, in order to produce a homogeneous spectral OLR dataset from 2008 to present. 

The dataset consists of monthly mean NETCDF files of around 500 MB each:
95 GB for Metop-A data (200801-202110)
66 GB for Metop-B (201304-202209)
and 23 GB for Metop-C (201907-202209)

Each file includes the gridded spectral OLR calculated separately for day and nighttime IASI observations. Missing values are set at NaN. Size of the grids: 91 lines (from -90 to 90 °N), 181 columns (from -180 to 180 °E), 6621 aisles (between 645 and 2300 cm-1 by step of 0.25 cm-1). Unit: W ∙ m-2 ∙ cm-1. 

The version number is 1.1 (delivered in December 2023).

IASI/Metop-A OLR data are available from January 2008 to October 2021.
IASI/Metop-B OLR data are available from April 2013 to September 2022.
IASI/Metop-C OLR data are available from July 2019 to September 2022.

Publication : Whitburn, S., Clarisse, L., Bauduin, S., George, M., Hurtmans, D., Safieddine, S., Coheur, P. F., and Clerbaux, C. (2020). Spectrally Resolved Fuxes from IASI Data: Retrieval algorithm for Clear-Sky Measurements. Journal of Climate. https://doi.org/10.1175/JCLI-D-19-0523.1

Any questions ? simon.whitburn@ulb.ac.be or lieven.clarisse@ulb.ac.be