Validation of the IASI FORLI/EUMETSAT ozone products using satellite (GOME-2), ground-based (Brewer–Dobson, SAOZ, FTIR) and ozonesonde measurements
| dc.contributor.author | Boynard, A. | |
| dc.contributor.author | Hurtmans, D. | |
| dc.contributor.author | Garane, K. | |
| dc.contributor.author | Goutail, F. | |
| dc.contributor.author | Hadji-Lazaro, J. | |
| dc.contributor.author | Koukouli, M.E. | |
| dc.contributor.author | Wespes, C. | |
| dc.contributor.author | Vigouroux, C. | |
| dc.contributor.author | Keppens, A. | |
| dc.contributor.author | Pommereau, J.-P. | |
| dc.contributor.author | Pazmino, A. | |
| dc.contributor.author | Balis, D. | |
| dc.contributor.author | Loyola, D. | |
| dc.contributor.author | Valks, P. | |
| dc.contributor.author | Sussmann, R. | |
| dc.contributor.author | Smale, D. | |
| dc.contributor.author | Coheur, P.-F. | |
| dc.contributor.author | Clerbaux, C. | |
| dc.date | 2018 | |
| dc.date.accessioned | 2018-09-13T09:40:05Z | |
| dc.date.available | 2018-09-13T09:40:05Z | |
| dc.identifier.uri | https://orfeo.belnet.be/handle/internal/7071 | |
| dc.description | This paper assesses the quality of IASI (Infrared Atmospheric Sounding Interferometer)/Metop-A (IASI-A) and IASI/Metop-B (IASI-B) ozone (O3) products (total and partial O3 columns) retrieved with the Fast Optimal Retrievals on Layers for IASI Ozone (FORLI-O3; v20151001) software for 9 years (2008–July 2017) through an extensive intercomparison and validation exercise using independent observations (satellite, ground-based and ozonesonde). Compared with the previous version of FORLI-O3 (v20140922), several improvements have been introduced in FORLI-O3 v20151001, including absorbance look-up tables recalculated to cover a larger spectral range, with additional numerical corrections. This leads to a change of ∼ 4% in the total ozone column (TOC) product, which is mainly associated with a decrease in the retrieved O3 concentration in the middle stratosphere (above 30hPa/25km). IASI-A and IASI-B TOCs are consistent, with a global mean difference of less than 0.3% for both daytime and nighttime measurements; IASI-A is slightly higher than IASI-B. A global difference of less than 2.4% is found for the tropospheric (TROPO) O3 column product (IASI-A is lower than IASI-B), which is partly due to a temporary issue related to the IASI-A viewing angle in 2015. Our validation shows that IASI-A and IASI-B TOCs are consistent with GOME-2 (Global Ozone Monitoring Experiment-2), Dobson, Brewer, SAOZ (Système d'Analyse par Observation Zénithale) and FTIR (Fourier transform infrared) TOCs, with global mean differences in the range of 0.1%–2% depending on the instruments compared. The worst agreement with UV–vis retrieved TOC (satellite and ground) is found at the southern high latitudes. The IASI-A and ground-based TOC comparison for the period from 2008 to July 2017 shows the long-term stability of IASI-A, with insignificant or small negative drifts of 1%–3%decade−1. The comparison results of IASI-A and IASI-B against smoothed FTIR and ozonesonde partial O3 columns vary with altitude and latitude, with the maximum standard deviation being seen for the 300–150hPa column (20%–40%) due to strong ozone variability and large total retrievals errors. Compared with ozonesonde data, the IASI-A and IASI-B O3 TROPO column (defined as the column between the surface and 300hPa) is positively biased in the high latitudes (4%–5%) and negatively biased in the midlatitudes and tropics (11%–13% and 16%–19%, respectively). The IASI-A-to-ozonesonde TROPO comparison for the period from 2008 to 2016 shows a significant negative drift in the Northern Hemisphere of −8.6±3.4%decade−1, which is also found in the IASI-A-to-FTIR TROPO comparison. When considering the period from 2011 to 2016, the drift value for the TROPO column decreases and becomes statistically insignificant. The observed negative drifts of the IASI-A TROPO O3 product (8%–16%decade−1) over the 2008–2017 period might be taken into consideration when deriving trends from this product and this time period. | |
| dc.language | eng | |
| dc.title | Validation of the IASI FORLI/EUMETSAT ozone products using satellite (GOME-2), ground-based (Brewer–Dobson, SAOZ, FTIR) and ozonesonde measurements | |
| dc.type | Article | |
| dc.subject.frascati | Earth and related Environmental sciences | |
| dc.audience | Scientific | |
| dc.source.title | Atmospheric Measurement Techniques | |
| dc.source.volume | 11 | |
| dc.source.issue | 9 | |
| dc.source.page | 5125-5152 | |
| Orfeo.peerreviewed | Yes | |
| dc.identifier.doi | 10.5194/amt-11-5125-2018 |
