IASI+GOME2 multispectral observation of ozone Overview

IASI+GOME2 is the multispectral observation of ozone at the lowermost troposphere and above from synergism of IASI thermal infrared and GOME-2 ultraviolet measurements ^{(1) (2)}. IASI+GOME2 has allowed the first satellite observation of the horizontal distribution of ozone pollution plumes located below 3 km of altitude. The maximum of sensitivity at the lowermost troposphere (between the surface and 3 km of altitude) is typically located over land between 2 and 2.5 km of altitude. This currently unique approach has been developed at the LISA laboratory (Laboratoire Inter-universitaire des Systèmes Atmosphériques UMR 7583 CNRS/UPEC/UPD), in collaboration with the Harvard-Smithonian Center for Astrophysics (USA), the Karlsruhe Institut für Technologie (Germany) and the Chinese Acadamy of Sciences (China). These innovative satellite observations offer a new potential for analysing ozone pollution from space.

IASI+GOME2 multispectral observations of ozone are daily derived at the global scale, from co-located IASI and GOME-2 measurements from morning overpasses of the MetOp satellite (around 8h30 local time for MetOp-B, see example in Figure 1), for low cloud-fraction scenes (GOME-2 pixels with cloud fractions below 30%). IASI+GOME2 jointly fits IASI and GOME-2 co-located spectra for deriving vertical profiles of ozone from the surface up to 60 km of altitude, at the IASI pixel resolution (12-km-pixels spaced by 25 km at nadir). Validation of these satellite observations validated against ozone sondes at global scale shows low mean bias (~3%), an average precision of ~16% and a linear correlation coefficient of 0.86 (for 46 launching sites, during all seasons of 2009-2010) ⁽³⁾. IASI+GOME2 has also shown good performance for observing surface ozone variability during pollution outbreaks over East Asia (with 6% mean bias, 0.69 correlation and 20% precision in April-May 2009).

Global IASI+GOME2 data is routinely produced at the ESPRI atmospheric data centre of the AERIS portal (http://www.aeris-data.fr). Development, validation and exploitation of the IASI+GOME2 approach is currently supported by the Centre National des Etudes Spatiales (CNES) via the SURVEYOZON project from Terre-Ocean Surface Continentale Atmosphere comitee (TOSCA), the Université Paris Est Créteil (UPEC) and the Centre National de Recherche Scientifique (CNRS). We also acknowledge the support the IASI+GOME2 development and analysis from the Programme National de Télédétection Spatiale (PNTS, grant PNTS-2013-05) and the SAKURA PHC partnership (grant 31894RE) between LISA and JAMSTEC laboratories.

Figure 1. Example of daily IASI+GOME2 observations of lowermost tropospheric ozone (ozone partial columns between the surface and 3 km of altitude above sea level in parts per billion volume mixing ratio - ppb) over the globe derived from the multispectral synergism of IASI and GOME-2 measurements onboard MetOp-B. Cloudy or uncovered regions are indicated in while.

The IASI+GOME2 product is provided as daily netcdf files with vertical profiles of ozone from the surface up to 60 km of altitude, selected partial ozone columns (including the lowermost troposphere), averaging kernels, error estimations, temperature and pressure profiles, surface temperature, cloud fraction and quality flags, after cloud screening and quality checks.

This AERIS/ESPRI portal of IASI+GOME2 data is currently under development. Very soon, it will offer a quicklook browser and direct download of data. For obtaining IASI+GOME2 data, please contact the Principal Investigator of the IASI+GOME2 project, Juan Cuesta, from the LISA laboratory: cuesta@lisa.u-pec.fr

The PI is entitled to be informed by email of any use of the IASI+GOME2 data. No charge is requested for the distribution of this dataset. Co-authorship is to be offered to the PI in case of use of IASI+GOME2 in a scientific publication (journal paper or presentation at conferences). In case that no co-authorship is needed, the use of IASI+GOME2 should be acknowledged as follows: « We thank the developers of the IASI+GOME2 product (LISA laboratory) and the AERIS portal for providing this dataset. ».

References

(1)	Cuesta, J., Eremenko, M., Liu, X., Dufour, G., Cai, Z., Höpfner, M., von Clarmann, T., Sellitto, P., Foret, G., Gaubert, B., Beekmann, M., Orphal, J., Chance, K., Spurr, R., and Flaud, J.-M.: Satellite observation of lowermost tropospheric ozone by multispectral synergism of IASI thermal infrared and GOME-2 ultraviolet measurements over Europe, Atmos. Chem. Phys., 13, 9675-9693, doi:10.5194/acp-13-9675-2013, 2013.
(2)	INSU/CNRS Press Alert and News: “Première observation de panaches d’ozone dans la très basse troposphère à partir de données satellitaires » from 2 October 2013, http://www.insu.cnrs.fr/node/4510
(3)	Cuesta, J., Y. Kanaya, M. Takigawa, G. Dufour, M. Eremenko, G. Foret, K. Miyazaki and M. Beekmann: Transboundary ozone pollution across East Asia: daily evolution and photochemical production analysed by IASI+GOME2 multispectral satellite observations and models, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2017-972, paper under review.