Atmospheric Measurement Techniques www.atmos-meas-tech.net 1867-1381 1867-8548 3 4 2010 10.5194/amt-3-991-2010 http://www.atmos-meas-tech.net/3/991/2010/ http://www.atmos-meas-tech.net/3/991/2010/amt-3-991-2010.html http://www.atmos-meas-tech.net/3/991/2010/amt-3-991-2010.pdf 991 1003 2010-07-30 Potential for the use of reconstructed IASI radiances in the detection of atmospheric trace gases N. C. Atkinson nigel.atkinson@metoffice.gov.uk F. I. Hilton S. M. Illingworth J. R. Eyre T. Hultberg Met Office, Fitzroy Road, Exeter, EX1 3PB, UK Department of Physics and Astronomy, University of Leicester, LE1 7RH, UK EUMETSAT, Eumetsat-Allee 1, 64295 Darmstadt, Germany Principal component (PC) analysis has received considerable attention as a technique for the extraction of meteorological signals from hyperspectral infra-red sounders such as the Infrared Atmospheric Sounding Interferometer (IASI) and the Atmospheric Infrared Sounder (AIRS). In addition to achieving substantial bit-volume reductions for dissemination purposes, the technique can also be used to generate reconstructed radiances in which random instrument noise has been reduced. Studies on PC analysis of hyperspectral infrared sounder data have been undertaken in the context of numerical weather prediction, instrument monitoring and geophysical variable retrieval, as well as data compression. This study examines the potential of PC analysis for chemistry applications. <br><br> A major concern in the use of PC analysis for chemistry is that the spectral features associated with trace gases may not be well represented in the reconstructed spectra, either due to deficiencies in the training set or due to the limited number of PC scores used in the radiance reconstruction. In this paper we show examples of reconstructed IASI radiances for several trace gases: ammonia, sulphur dioxide, methane and carbon monoxide. It is shown that care must be taken in the selection of spectra for the initial training set: an iterative technique, in which outlier spectra are added to a base training set, gives the best results. For the four trace gases examined, key features of the chemical signatures are retained in the reconstructed radiances, whilst achieving a substantial reduction in instrument noise. <br><br> A new regional re-transmission service for IASI is scheduled to start in 2010, as part of the EUMETSAT Advanced Retransmission Service (EARS). For this EARS-IASI service it is intended to include PC scores as part of the data stream. The paper describes the generation of the reference eigenvectors for this new service. Antonelli, P., Revercomb, H E., Sromovsky, L., Smith, W L., Knuteson, R O., Tobin, D C., Garcia, R K., Howell, H B., Huang, H.-L., and Best, F A.: A principal component noise filter for high spectral resolution infrared measurements, J. Geophys. Res., 109, D23102, doi:10.1029/2004JD004862, 2004. Atkinson, N C., Brunel, P., Marguinaud, P., and Labrot, T.: AAPP developments and experiences with processing METOP data, Tech. Proc. 16th Int. TOVS Study Conf., Angra dos Reis, Brazil, 6–13~May, 2008. Atkinson, N C., Ponsard, C., and Hultberg, T.: AAPP enhancements for the EARS-IASI service, Proc. EUMETSAT Meteorological Satellite Conf., Bath, UK, 21–25~September, 2009. Barret, B., Turquety, S., Hurtmans, D., Clerbaux, C., Hadji-Lazaro, J., Bey, I., Auvray, M., and Coheur, P.-F.: Global carbon monoxide vertical distributions from spaceborne high-resolution FTIR nadir measurements, Atmos. Chem. Phys., 5, 2901–2914, doi:10.5194/acp-5-2901-2005, 2005. Beer, R., Shephard, M W., Kulawik, S S., Clough, S A., Eldering, A., Bowman, K W., Sander, S P., Fisher, B M., Payne, V H., Luo, M., Osterman, G B., and Worden, J R.: First satellite observations of lower tropospheric ammonia and methanol, Geophys. Res. Lett., 35, L09801, doi:10.1029/2008GL033642, 2008. Chipperfield, M P.: New version of the TOMCAT/SLIMCAT off-line chemical transport model: Intercomparison of stratospheric tracer experiments, Q. J. Roy. Meteor. Soc., 132, 1179–1203, 2006. Clarisse, L., Coheur, P F., Prata, A J., Hurtmans, D., Razavi, A., Phulpin, T., Hadji-Lazaro, J., and Clerbaux, C.: Tracking and quantifying volcanic SO₂ with IASI, the September~2007 eruption at Jebel at Tair, Atmos. Chem. Phys., 8, 7723–7734, doi:10.5194/acp-8-7723-2008, 2008a. Clarisse, L., Coheur, P.-F., Hurtmans, D., Clerbaux, C., Turquety, S., and Hadji-Lazaro, J.: IASI measurements of Trace Species and Particles in Volcanic and Fire Plumes, ACCENT-TROPOSAT-2 Activities 2007–2008 and Final Report, 82–86, 2008b. Clarisse, L., Clerbaux, C., Dentener, F., Hurtmans, D., and Coheur, P.-F.: Global ammonia distribution derived from infrared satellite observations, Nat. Geosci., 2, 479–483, 2009. Clerbaux, C., Boynard, A., Clarisse, L., George, M., Hadji-Lazaro, J., Herbin, H., Hurtmans, D., Pommier, M., Razavi, A., Turquety, S., Wespes, C., and Coheur, P.-F.: Monitoring of atmospheric composition using the thermal infrared IASI/MetOp sounder, Atmos. Chem. Phys., 9, 6041–6054, doi:10.5194/acp-9-6041-2009, 2009. Coheur, P.-F., Clarisse, L., Turquety, S., Hurtmans, D., and Clerbaux, C.: IASI measurements of reactive trace species in biomass burning plumes, Atmos. Chem. Phys., 9, 5655–5667, doi:10.5194/acp-9-5655-2009, 2009. Collard, A D.: Selection of IASI channels for use in numerical weather prediction, ECMWF Tech. Memorandum, 532, 2007. Collard, A D.: NWPSAF ECMWF IASI PCA-Based Compression Package Manual, NWP SAF document NWPSAF-EC-UD-011, available online at: http://www.nwpsaf.org/, 2008. Crevoisier, C., Chédin, A., Matsueda, H., Machida, T., Armante, R., and Scott, N A.: First year of upper tropospheric integrated content of CO₂ from IASI hyperspectral infrared observations, Atmos. Chem. Phys., 9, 4797–4810, doi:10.5194/acp-9-4797-2009, 2009. Crevoisier, C., Nobileau, D., Fiore, A M., Armante, R., Chédin, A., and Scott, N A.: Tropospheric methane in the tropics – first year from IASI hyperspectral infrared observations, Atmos. Chem. Phys., 9, 6337–6350, doi:10.5194/acp-9-6337-2009, 2009. Edwards, D P.: GENLN2: A general line-by-line atmospheric transmittance and radiance model, NCAR Tech.Note, NCAR/TN-367+STR, 1992. George, M., Clerbaux, C., Hurtmans, D., Turquety, S., Coheur, P.-F., Pommier, M., Hadji-Lazaro, J., Edwards, D P., Worden, H., Luo, M., Rinsland, C., and McMillan, W.: Carbon monoxide distributions from the IASI/METOP mission: evaluation with other space-borne remote sensors, Atmos. Chem. Phys., 9, 8317–8330, doi:10.5194/acp-9-8317-2009, 2009. Goldberg, M D., Qu, Y., McMillin, L M., Wolf, W., Zhou, L., and Divakarla, M.: AIRS near- real-time products and algorithms in support of operational numerical weather prediction, IEEE Trans. Geosci. Rem. Sens., 41, 379–389, 2003. Hilton, F., Atkinson, N C., English, S J., and Eyre, J R.: Assimilation of IASI at the Met Office and assessment of its impact through observing system experiments, Q. J. Roy. Meteor. Soc., 135, 495–505, 2009a. Hilton, F. and Collard, A D.: Recommendations for the use of principal component-compressed observations from infrared hyperspectral sounders, Met Office Forecasting Research and Development Technical Report 536, available online at: http://research.metoffice.gov.uk/research/nwp/publications/papers/technical_reports/, access: 3~June~2010, 2009b. Hultberg, T.: IASI Principal Component Compression (IASI PCC) FAQ, Technical Note, available online at: http://www.eumetsat.int/Home/Main/DataProducts/Resources/index.htm, access: 27~July~2010, 2009. Hultberg, T.: IASI Principal Component Compression (PCC) – first experiences, 2nd IASI International Conference, Annecy, 25–29 January, 2010. Illingworth, S M., Remedios, J J., Boesch, H., Moore, D P., Sembhi, H., Dudia, A., and Walker, J C.: A New Optimal Estimation Retrieval Scheme for Carbon Monoxide using IASI spectral radiances: Part I Sensitivity Analysis, Error Budget and Simulations, in preparation, 2010. Phulpin, T., Blumstein, D., Prel, F., Tournier, B., Prunet, P., and Schlussel, P.: Applications of IASI on MetOp-A: first results and illustration of potential use for meteorology, climate monitoring, and atmospheric chemistry, Proc. SPIE, 6684, 66840F, 2007. Razavi, A., Clerbaux, C., Wespes, C., Clarisse, L., Hurtmans, D., Payan, S., Camy-Peyret, C., and Coheur, P F.: Characterization of methane retrievals from the IASI space-borne sounder, Atmos. Chem. Phys., 9, 7889–7899, doi:10.5194/acp-9-7889-2009, 2009. Ricaud, P., Attié, J.-L., Teyssèdre, H., El Amraoui, L., Peuch, V.-H., Matricardi, M., and Schluessel, P.: Equatorial total column of nitrous oxide as measured by IASI on MetOp-A: implications for transport processes, Atmos. Chem. Phys., 9, 3947–3956, doi:10.5194/acp-9-3947-2009, 2009. Rodgers, C.: Inverse Methods for Atmospheric Sounding: Theory and Practice, World Scientific, 2000. Seemann, S W., Borbas, E E., Knuteson, R O., Stephenson, G R., and Huang, H.-L.: Development of a global infrared land surface emissivity database for application to clear sky sounding retrievals, J. Appl. Meteorol. Climatol., 47, 108–123, 2008. Siméoni, D., Singer, C., and Chalon, G.: Infrared atmospheric sounding interferometer, Acta Astronautica, 40, 113–118, 1997. Turquety, S., Hurtmans, D., Hadji-Lazaro, J., Coheur, P.-F., Clerbaux, C., Josset, D., and Tsamalis, C.: Tracking the emission and transport of pollution from wildfires using the IASI CO retrievals: analysis of the summer 2007 Greek fires, Atmos. Chem. Phys., 9, 4897–4913, doi:10.5194/acp-9-4897-2009, 2009.