1UPMC Univ. Paris 06, Université Versailles St-Quentin, CNRS/INSU, UMR 8190, LATMOS-IPSL, Paris, France
2UPMC Univ. Paris 06, Ecole Polytechnique, CNRS UMR 8539, LMD-IPSL, Palaiseau, France
3Spectroscopie de l'Atmosphère, Chimie Quantique et Photophysique, Université Libre de Bruxelles (ULB), Brussels, Belgium
4DLR, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
5LSCE/IPSL, CEA-CNRS-UVSQ, Saclay, France
6Université de Toulouse, UPS, LA (Laboratoire d'Aérologie), CNRS UMR 5560, Toulouse, France
7NASA Langley Research Center, MS 483, Hampton, USA
8NASA Ames Research Center, Moffett Field, California, 94035, USA
9Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA
10Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
11Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1, Canada
12Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
Received: 22 Apr 2010 – Discussion started: 09 Jun 2010
Abstract. In this paper, we provide a detailed comparison between carbon monoxide (CO) data measured by the Infrared Atmospheric Sounding Interferometer (IASI)/MetOp and aircraft observations over the Arctic. The CO measurements were obtained during North American (NASA ARCTAS and NOAA ARCPAC) and European campaigns (POLARCAT-France, POLARCAT-GRACE and YAK-AEROSIB) as part of the International Polar Year (IPY) POLARCAT activity in spring and summer 2008. During the campaigns different air masses were sampled including clean air, polluted plumes originating from anthropogenic sources in Europe, Asia and North America, and forest fire plumes originating from Siberia and Canada. The paper illustrates that CO-rich plumes following different transport pathways were well captured by the IASI instrument, in particular due to the high spatial coverage of IASI. The comparison between IASI CO total columns, 0–5 km partial columns and profiles with collocated aircraft data was achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of information content and surface properties at the location of the observations. For profiles, the data were found to be in good agreement in spring with differences lower than 17%, whereas in summer the difference can reach 20% for IASI profiles below 8 km for polluted cases. For total columns the correlation coefficients ranged from 0.15 to 0.74 (from 0.47 to 0.77 for partial columns) in spring and from 0.26 to 0.84 (from 0.66 to 0.88 for partial columns) in summer. A better agreement is seen over the sea in spring (0.73 for total column and 0.78 for partial column) and over the land in summer (0.69 for total columns and 0.81 for partial columns). The IASI vertical sensitivity was better over land than over sea, and better over land than over sea ice and snow allowing a higher potential to detect CO vertical distribution during summer.
Revised: 07 Oct 2010 – Accepted: 08 Nov 2010 – Published: 12 Nov 2010
Pommier, M., Law, K. S., Clerbaux, C., Turquety, S., Hurtmans, D., Hadji-Lazaro, J., Coheur, P.-F., Schlager, H., Ancellet, G., Paris, J.-D., Nédélec, P., Diskin, G. S., Podolske, J. R., Holloway, J. S., and Bernath, P.: IASI carbon monoxide validation over the Arctic during POLARCAT spring and summer campaigns, Atmos. Chem. Phys., 10, 10655-10678, doi:10.5194/acp-10-10655-2010, 2010.