Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 6 6 2006 10.5194/acpd-6-13027-2006 http://www.atmos-chem-phys-discuss.net/6/13027/2006/ http://www.atmos-chem-phys-discuss.net/6/13027/2006/acpd-6-13027-2006.html http://www.atmos-chem-phys-discuss.net/6/13027/2006/acpd-6-13027-2006.pdf 13027 13073 2006-12-12 Interference errors in infrared remote sounding of the atmosphere R. Sussmann ralf.sussmann@imk.fzk.de T. Borsdorff IMK-IFU, Forschungszentrum Karlsruhe, Garmisch-Partenkirchen, Germany More and more profiles of atmospheric state parameters are being retrieved from remote soundings in the infrared spectral domain. Classical error analysis, which was originally applied to microwave sounding systems, distinguishes between "smoothing errors," "forward model errors," "forward model parameter errors," and "retrieval noise errors". We show that for infrared soundings "interference errors", which have not been treated up to now, can be significant. Interference errors originate from "interfering species" that introduce signatures into the spectral measurement which overlap with the spectral features used for retrieval of the target species. This is a frequent situation in infrared atmospheric spectra where the vibration-rotation bands of different species often overlap; it is not the case in the microwave region. This paper presents a full theoretical formulation of interference errors. It requires a generalized state vector including profile entries for all interfering species. This leads to a generalized averaging kernel matrix made up of classical averaging kernels plus here defined "interference kernels". The latter are used together with climatological covariances for the profiles of the interfering species in order to quantify the interference errors. To illustrate the methods we apply them to a real sounding and show that interference errors have a significant impact on standard CO profile retrievals from ground-based mid-infrared solar absorption spectra. We also demonstrate how to minimize overall error, which is a trade-off between minimizing interference errors and the smoothing error. The approach used in this paper can be applied to soundings of all infrared-active atmospheric species, which includes more than two dozen different gases relevant to climate and ozone. And this holds for all kind of infrared remote sounding systems, i.e., retrievals from ground-based, balloon-borne, airborne, or satellite spectroradiometers. Connor, B. J., Parrish, A., Tsou, J.-J., and McCormick, M. P.: Error analysis for the ground-based microwave ozone measurements during STOIC, J. Geophys. Res., 100, 9283–9291, 1995. Deeter, M. N., Emmons, L. K., Francis, G. L., Edwards, D. P., Gille, J. C., Warner, J. X., Khattatov, B., Ziskin, D., Lamarque, J.-F., Ho, S.-P., Yuding, V., Attie, J.-L. Packman, D., Chen, J., Mao, D., and Drummond, J. R.: Operational carbon monoxide retrieval algorithm and selected results for the MOPITT instrument, J. Geophys. Res., 108, 4399–4409, 2003. Jones, N. B., Rinsland, C. P., Liley, J. B., and Rosen, J.: Correlation of aerosol and carbon monoxide at 45° S: Evidence of biomass burning emissions, Geophys. Res. Lett., 28, 709–712, 2001. Paton-Walsh, C., Jones, N. B., Wilson, S. R., Haverd, V., Meier, A., Griffith, D. W. T., and Rinsland, C. P.: Measurements of trace gas emissions from Australian forest fires and correlations with coincident measurements of aerosol optical depth, J. Geophys. Res., 110, D24305, doi:10.1029/2005JD006202, 2005. Pougatchev, N. S. and Rinsland, C. P.: Spectroscopic study of the seasonal variation of carbon monoxide vertical distribution above Kitt Peak, J. Geophys. Res., 100, 1409–1416, 1995. Pougatchev, N. S., Jones, N. B., Connor, B. J., Rinsland, C. P., Becker, E., Coffey, M. T., Connors, V.S., Demoulin, P., Dzhola, A.V., Fast, H., Grechko, E.I., Hannigan, J. W., Koike, M., Kondo, Y., Mahieu, E., Mankin, W.G., Mittermeier, R. L., Notholt, J., Reichle Jr, H. G., Sen, B., Steele, L.P., Toon, G. C., Yurganov, L. N., Zander, R., and Zhao, Y.: Ground-based infrared solar spectroscopic measurements of carbon monoxide during 1994 Measurement of Air Pollution from Space flights, J. Geophys. Res., 103(D15), 19 317–19 325, 1998. Rinsland, C. P., Jones, N. B., Connor, B. J., Logan, J. A., Pougatchev, N. S., Goldman, A., Murcray, F. J., Stephen, T. M., Pine, A. S., Zander, R., Mahieu, E., and Demoulin, P.: Northern and southern hemisphere ground-based infrared spectroscopic measurements of tropospheric carbon monoxide and ethane, J. Geophys. Res., 103, 28 197–28 217, 1998. Rinsland, C. P., Mahieu, E., Zander, R., Demoulin, P., Forrer, J., and Buchmann, B.: Free tropospheric CO, C₂H$_6$, and HCN over central Europe: Recent measurements from the Jungfraujoch station including the detection of elevated columns during 1998, J. Geophys. Res., 105, 24 235–24 249, 2000. Rodgers, C. D.: Retrieval of Atmospheric Temperature and Composition From Remote Measurements of Thermal Radiation, Rev. Geophys. Space Phys., 14, 609–624, 1976. Rodgers, C. D.: Characterization and Error Analysis of Profiles Retrieved From Remote Sounding Measurements, J. Geophys. Res., 95, 5587–5595, 1990. Rodgers, C. D.: Inverse Methods for Atmospheric Sounding: Theory and Practice, vol. 2 of Series on Atmospheric, Oceanic and Planetary Physics, edited by: Taylor, F. W., World Scientific, 2000. Rodgers, C. D. and Connor, B. J.: Intercomparison of remote sounding instruments, J. Geophys. Res., 108(D3), 4116, doi:10.1029/2002JD002299, 2003. Rothmann, L. S., Barbe, A., Benner, D. C., Brown, L. R., Camy-Peyret, C., Carleer, M. R., Chance, K., Clerbaux, C., Dana, V., Devi, V. M., Fayt, A., Flaud, J. M., Gamache, R. R., Goldman, A., Jacquemart, D., Jucks, K. W., Lafferty, W. J., Mandin, J. Y., Massie, S. T., Nemtchinov, V., Newnham, D. A., Perrin, A., Rinsland, C. P., Schroeder, J., Smith, K. M., Smith, M. A. H., Tang, K., Toth, R. A., Vander Auwera, J., Varanasi, P., and Yoshino, K.: The HITRAN molecular spectroscopic database: edition of 2000 including updates through 2001, J. Quant. Spectrosc. Radiat. Transfer, 82, 5–44, 2003. Seiler, W. and Warneck, P.: Decrease of carbon monoxide mixing ratio at the tropopause, J. Geophys. Res., 77, 3204–3214, 1972. Seiler, W. and Fishman, J., The distribution of carbon monoxide and ozone in the free troposphere, J. Geophys. Res., 86, 7255–7265, 1981. Steck, T. and von Clarmann, T.: Constrained profile retrieval applied to the observation mode of the Michelson Interferometer for Passive Atmospheric Sounding, Appl. Opt., 40, 3559–3571, 2001. Steck, T.: Methods for determining regularization for atmospheric retrieval problems, Appl. Opt., 41, 1788–1797, 2002. Sussmann, R. and Schäfer, K.: Infrared spectroscopy of tropospheric trace gases: combined analysis of horizontal and vertical column abundances, Appl. Opt., 36, 735–741, 1997. Sussmann, R. and Buchwitz, M.: Initial validation of ENVISAT/SCIAMACHY columnar CO by FTIR profile retrievals at the Ground-Truthing Station Zugspitze, Atmos. Chem. Phys., 5, 1497–1503, 2005. Sussmann, R., Stremme, W. Buchwitz, M., and de Beek, R.: Validation of ENVISAT/SCIAMACHY columnar methane by solar FTIR spectrometry at the Ground-Truthing Station Zugspitze, Atmos. Chem. Phys., 5, 2419–2429, 2005a. Sussmann, R., Stremme, W., Burrows, J.P., Richter, A., Seiler, W., and Rettinger, M.: Stratospheric and tropospheric NO₂ variability on the diurnal and annual scale: a combined retrieval from ENVISAT/SCIAMACHY and solar FTIR at the Permanent Ground-Truthing Facility Zugspitze/Garmisch, Atmos. Chem. Phys., 5, 2657–2677, 2005b, Tikhonov, A.: On the solution of incorrectly stated problems and a method of regularization, Dokl. Acad. Nauk SSSR, 151, 501–504, 1963. Velazco, V., Notholt, J., Warneke, T., Lawrence, M., Bremer, H., Drummond, J., Schulz, A., Krieg, J., and Schrems, O.: Latitude and altitude variability of carbon monoxide in the Atlantic detected from ship-borne Fourier transform spectrometry, model, and satellite data, J. Geophys. Res., 110, D09306, doi:10.1029/2004JD005351, 2005. Yurganov, L. N., Blumenstock, T., Grechko, E. I., Hase, F., Hyer, E. J., Kasischke, E. S., Koike, M., Kondo, Y., Kramer, I., Leung, F.-Y., Mahieu, E., Mellqvist, J., Notholt, J., Novelli, P. C., Rinsland, C. P., Scheel, H. E., Schulz, A., Strandberg, A., Sussmann, R., Tanimoto, H., Velazco, V., Zander, R., and Zhao, Y.: A quantitative assessment of the 1998 carbon monoxide emission anomaly in the Northern Hemisphere based on total column and surface concentration measurements, J. Geophys. Res., 109, D15305, doi:10.1029/2004JD004559, 2004. Yurganov, L. N., Duchatelet, P., Dzhola, A. V., Edwards, D. P., Hase, F., Kramer, I., Mahieu, E., Mellqvist, J., Notholt, J., Novelli. P. C., Rockmann, A., Scheel, H. E., Schneider, M., Schulz, A., Strandberg, A., Sussmann, R., Tanimoto, H., Velazco, V., Drummond, J. R., and Gille, J. C.: Increased Northern Hemispheric carbon monoxide burden in the troposphere in 2002 and 2003 detected from the ground and from space, Atmos. Chem. Phys., 5, 563–573, 2005, Zhao, Y., Kondo, Y., Murcray, F.J., Liu, X., Koike, M., Kita, K., Nakajima, H., Murata, I., and Suzuki, K.: Carbon monoxide column abundances and tropospheric concentrations retrieved from high resolution ground-based infrared solar spectra at 43.5\r N over Japan, J. Geophys. Res., 102(D19), 23 403–23 411, 1997.