Seven years of IASI ozone retrievals from FORLI: validation with independent
total column and vertical profile measurements
-
Published:2016-09-06
Issue:9
Volume:9
Page:4327-4353
-
ISSN:1867-8548
-
Container-title:Atmospheric Measurement Techniques
-
language:en
-
Short-container-title:Atmos. Meas. Tech.
Author:
Boynard Anne, Hurtmans Daniel, Koukouli Mariliza E.ORCID, Goutail FlorenceORCID, Bureau Jérôme, Safieddine SarahORCID, Lerot Christophe, Hadji-Lazaro Juliette, Wespes Catherine, Pommereau Jean-PierreORCID, Pazmino Andrea, Zyrichidou Irene, Balis DimitrisORCID, Barbe Alain, Mikhailenko Semen N.ORCID, Loyola DiegoORCID, Valks Pieter, Van Roozendael Michel, Coheur Pierre-François, Clerbaux Cathy
Abstract
Abstract. This paper presents an extensive intercomparison and validation for the ozone (O3) product measured by the two Infrared Atmospheric Sounding Interferometers (IASIs) launched on board the MetOp-A and MetOp-B satellites in 2006 and in 2012 respectively. IASI O3 total columns and vertical profiles obtained from Fast Optimal Retrievals on Layers for IASI (FORLI) v20140922 software (running up until recently) are validated against independent observations during the period 2008–2014 on a global scale. On average for the period 2013–2014, IASI-A and IASI-B total ozone columns (TOCs) retrieved using FORLI are consistent, with IASI-B providing slightly lower values with a global difference of only 0.2 ± 0.8 %. The comparison between IASI-A and IASI-B O3 vertical profiles shows differences within ± 2 % over the entire altitude range. Global validation results for 7 years of IASI TOCs from FORLI against the Global Ozone Monitoring Experiment-2 (GOME-2) launched on board MetOp-A and Brewer–Dobson data show that, on average, IASI overestimates the ultraviolet (UV) data by 5–6 % with the largest differences found in the southern high latitudes. The comparison with UV–visible SAOZ (Système d'Analyse par Observation Zénithale) measurements shows a mean bias between IASI and SAOZ TOCs of 2–4 % in the midlatitudes and tropics and 7 % at the polar circle. Part of the discrepancies found at high latitudes can be attributed to the limited information content in the observations due to low brightness temperatures. The comparison with ozonesonde vertical profiles (limited to 30 km) shows that on average IASI with FORLI processing underestimates O3 by ∼ 5–15 % in the troposphere while it overestimates O3 by ∼ 10–40 % in the stratosphere, depending on the latitude. The largest relative differences are found in the tropical tropopause region; this can be explained by the low O3 amounts leading to large relative errors. In this study, we also evaluate an updated version of FORLI-O3 retrieval software (v20151001), using look-up tables recalculated to cover a larger spectral range using the latest HITRAN spectroscopic database (HITRAN 2012) and implementing numerical corrections. The assessment of the new O3 product with the same set of observations as that used for the validation exercise shows a correction of ∼ 4 % for the TOC positive bias when compared to the UV ground-based and satellite observations, bringing the overall global comparison to ∼ 1–2 % on average. This improvement is mainly associated with a decrease in the retrieved O3 concentration in the middle stratosphere (above 30 hPa/25 km) as shown by the comparison with ozonesonde data.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference84 articles.
1. Antón, M., Loyola, D., Clerbaux, C., López, M., Vilaplana, J. M., Bañón, M., Hadji-Lazaro, J., Valks, P., Hao, N., Zimmer, W., Coheur, P. F., Hurtmans, D., and Alados-Arboledas, L.: Validation of the MetOp-A total ozone data from GOME-2 and IASI using reference ground-based measurements at the Iberian Peninsula, Remote Sens. Environ., 115, 1380–1386, 2011. 2. Aeris: IASI L1C data and L2 temperature data along with IASI O3 products processed with FORLI-O3 v20151001, Institut Pierre Simon Laplace (France), Centre National de la Recherche Scientifique (CNRS, France), Centre National d'Etudes Spatiales (CNES), available at: http://www.aeris-data.fr, last access: 31 August 2016. 3. August, T., Klaes, D., Schlüssel, P., Hultberg, T., Crapeau, M., Arriaga, A., O'Carroll, A., Coppens, D., Munro, R., and Calbet, X.: IASI on Metop-A: Operational Level 2 retrievals after five years in orbit, J. Quant. Spectrosc. Ra., 113, 1340–1371, https://doi.org/10.1016/j.jqsrt.2012.02.028, 2012. 4. Balis, D., Kroon, M., Koukouli, M. E., Labow, G., Veefkind, J. P., and McPeters, R. D.: Validation of Ozone Monitoring Instrument total ozone column measurements using Brewer and Dobson spectrophotometer ground based observations, J. Geophys. Res., 112, D24S46, https://doi.org/10.1029/2007JD008796, 2007a. 5. Balis, D., Lambert, J.-C., Van Roozendael, M., Spurr, R., Loyola, D., Livschitz, Y., Valks, P., Amiridis, V., Gerard, P., Granville, J., and Zehner, C.: Ten years of GOME/ERS2 total ozone data the new GOME data processor (GDP) version 4: 2. Ground-based validation and comparisons with TOMS V7/V8, J. Geophys. Res., 112, D07307, https://doi.org/10.1029/2005JD00637, 2007b.
Cited by
36 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|