IASI L2 ozone (O₃) climate data record

Description

The IASI L2 ozone (O₃) Climate Data Record (CDR) provides O₃ concentrations and auxiliary variables used to build atmospheric profiles of O₃ observations. DOI: 10.15770/EUM_SAF_AC_0051

Type

Climate data record

Satellites and instruments

IASI/Metop-A and IASI/Metop-B

Algorithm version

FORLI O3 v20151001

Time period

• 10/07/2007 - 31/12/2019 (IASI/Metop-A)
• 20/02/2013 - 31/12/2023 (IASI/Metop-B)

Theoretical basis

The Fast Optimal Retrievals on Layers for IASI (FORLI) algorithm retrieval of this product is based on the optimal estimation method. It relies on a radiative transfer model based on precalculated Look up Tables (LUTs) and an inversion scheme to process IASI level 1C radiances.

Processing

FORLI is a dedicated radiative transfer and retrieval software for IASI. It was developed at the Université Libre de Bruxelles (ULB) in collaboration with LATMOS, with the objective to provide global concentration distributions of atmospheric trace gases.

Units and spatial resolution

O₃ profiles are given in molecules/cm². In 8 seconds a total of 120 views are collected over a swath of ∼2200 km, divided as 30 arrays of four individual pixels varying in size from 36 x π km² at nadir (circular pixel 12 km in diameter) to 10 x 20 x π km² at larger viewing angles.

Validation

This product is validated using satellite and ozone sonde data. See Boynard et al., 2025.

Archiving and dissemination

This product is available via the EUMETSAT Data Store.

File format and size

This product is available in NetCDF format, each day containing 13-14 orbits/instrument. The size of each orbit is on average 35 MB, which gives a total size of around 490 MB/day/instrument.

Documents

• Product user manual
• Algorithm theoretical basis document

Reference

Boynard, A., Wespes, C., Hadji-Lazaro, J., Sinnathamby, S., Hurtmans, D., Coheur, P.-F., Doutriaux-Boucher, M., Onderwaater, J., Steinbrecht, W., Pennington, E.A., Bowman, K., and Clerbaux, C.: Tropospheric Ozone Assessment Report (TOAR): 16-year ozone trends from the IASI Climate Data Record, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-1054, 2025.