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Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Vol. 43, Iss. 11 — Apr. 10, 2004
  • pp: 2369–2383

Systematic errors inherent in the current modeling of the reflected downward flux term used by remote sensing models

David S. Turner  »View Author Affiliations


Applied Optics, Vol. 43, Issue 11, pp. 2369-2383 (2004)
http://dx.doi.org/10.1364/AO.43.002369


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Abstract

An underlying assumption of satellite data assimilation systems is that the radiative transfer model used to simulate observed satellite radiances has no errors. For practical reasons a fast-forward radiative transfer model is used instead of a highly accurate line-by-line model. The fast model usually replaces the spectral integration of spectral quantities with their monochromatic equivalents, and the errors due to these approximations are assumed to be negligible. The reflected downward flux term contains many approximations of this nature, which are shown to introduce systematic errors. In addition, many fast-forward radiative transfer models simulate the downward flux as the downward radiance along a path defined by the secant of the mean emergent angle, the diffusivity factor. The diffusivity factor is commonly set to 1.66 or to the secant of the satellite zenith angle. Neither case takes into account that the diffusivity factor varies with optical depth, which introduces further errors. I review the two most commonly used methods for simulating reflected downward flux by fast-forward radiative transfer models and point out their inadequacies and limitations. An alternate method of simulating the reflected downward flux is proposed. This method transforms the surface-to-satellite transmittance profile to a transmittance profile suitable for simulating the reflected downward flux by raising the former transmittance to the power of κ, where κ itself is a function of channel, surface pressure, and satellite zenith angle. It is demonstrated that this method reduces the fast-forward model error for low to moderate reflectivities.

© 2004 Optical Society of America

OCIS Codes
(010.0010) Atmospheric and oceanic optics : Atmospheric and oceanic optics
(280.0280) Remote sensing and sensors : Remote sensing and sensors

History
Original Manuscript: July 21, 2003
Revised Manuscript: December 31, 2003
Published: April 10, 2004

Citation
David S. Turner, "Systematic errors inherent in the current modeling of the reflected downward flux term used by remote sensing models," Appl. Opt. 43, 2369-2383 (2004)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-43-11-2369


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References

  1. J. C. Derber, W.-S. Wu, “The use of TOVS cloud-cleared radiances in the NCEP SSI analysis system,” Mon. Weather Rev. 126, 2287–2299 (1998). [CrossRef]
  2. M. J. Uddstrom, L. M. McMillin, “System noise in the NESDIS TOVS forward model. Part I: specification,” J. Appl. Meteorol. 33, 919–938 (1994). [CrossRef]
  3. J. R. Eyre, G. Kelly, A. P. McNally, E. Andersson, “Assimilation of TOVS radiances through one dimensional variational analysis,” Q. J. R. Meteorol. Soc. 119, 1427–1463 (1993). [CrossRef]
  4. B. A. Harris, G. Kelly(2001): A satellite radiance-bias correction scheme for data assimilation. Q. J. R. Meteorol. Soc. 127, 1453–1468 (2001). [CrossRef]
  5. J. R. Eyre, “A bias correction scheme for simulated TOVS brightness temperatures,” ECMWF Research Department Technical Memo 186 (European Centre for Medium-Range Weather Forecasts, Reading, UK, 1992).
  6. W. L. Smith, H. M. Woolf, C. M. Hayden, D. Q. Wark, L. M. McMillin, “The TIROS-N operational vertical sounder,” Bull. Am. Meteorol. Soc. 60, 1177–1187 (1979).
  7. R. W. Saunders, M. Matricardi, P. Brunel, “An improved fast radiative transfer model for assimilation of satellite radiance observations,” Q. J. R. Meteorol. Soc. 125, 1407–1425 (1999).
  8. L. M. McMillin, L. J. Crone, T. J. Kleespies, “Atmospheric transmittance of an absorbing gas. 5. Improvements to the OPTRAN approach,” Appl. Opt. 34, 8396–8399 (1995). [CrossRef] [PubMed]
  9. L. Garand, D. S. Turner, C. Chouinard, J. Hallé, “A physical formulation of atmospheric transmittances for the massive assimilation of satellite infrared radiances,” J. Appl. Meteorol. 38, 541–554 (1999). [CrossRef]
  10. B. Soden, S. Tjemkes, J. Schmetz, R. Saunders, J. Bates, B. Ellingson, R. Engelen, L. Garand, D. Jackson, G. Jedlovec, T. Kleespies, D. Randel, P. Rayer, E. Salathe, D. Schwarzkopf, N. Scott, B. Sohn, S. de Souza-Machado, L. Strow, D. Tobin, D. Turner, P. van Delst, T. Wehr, “An intercomparison of radiation codes for retrieving upper-tropospheric humidity in the 6.3 μm band: a report from the first GvaP workshop,” Bull. Am. Meteorol. Soc. 81, 797–808 (2000). [CrossRef]
  11. L. Garand, D. S. Turner, M. Larocque, J. Bates, S. Boukabara, P. Brunel, F. Chevallier, G. DeBlonde, R. Engelen, M. Hollingshead, D. Jackson, G. Jedlovec, J. Joiner, T. Kleespies, D. S. McKague, L. McMillin, J.-L. Moncet, J. R. Pardo, P. J. Rayer, E. Salathe, R. Saunders, N. A. Scott, P. van Delst, H. Woolf, “Radiance and Jacobian intercomparison of radiative transfer models applied to HIRS and AMSU channels,” J. Geophys. Rev. 106, 24017–24031 (2001). [CrossRef]
  12. M. Matricardi, F. Chevallier, S. Tjemkes, “An improved general fast radiative transfer model for the assimilation of radiance observations,” ECMWF Technical Memo 345, (European Centre for Medium Range Weather Forecasts, Reading, UK, 2001).
  13. D. S. Turner, C. B. Chouinard, “An attempt to understand and correct some of the errors of forward radiative transfer models,” in Technical Proceedings of the Ninth International TOVS Study Conference (European Centre for Medium-Range Weather Forecasts, Reading, UK, 1997), pp. 499–508.
  14. D. S. Turner, “Systematic errors that are due to the monochromatic-equivalent radiative transfer approximation in thermal emission problems,” Appl. Opt. 39, 5663–5670 (2000). [CrossRef]
  15. K. N. Liou, “Diffusivity factor in infrared radiative transfer” in Radiation and Cloud Processes in the Atmosphere (Oxford U. Press, New York, 1992), pp. 41–43.
  16. D. S. Turner, “Absorption coefficient estimation using a two-dimensional interpolation procedure,” J. Quant. Spectrosc. Radiat. Transfer 53, 633–637 (1995). [CrossRef]
  17. L. S. Rothman, C. P. Rinsland, A. Goldman, S. T. Massie, D. P. Edwards, J.-M. Flaud, A. Perrin, C. Camy-Peyret, V. Dana, J.-Y. Mandin, J. Schroeder, A. McCann, R. R. Gamache, R. B. Wattson, K. Yoshino, K. V. Chance, K. W. Jucks, L. R. Brown, V. Nemtchinov, P. Varanasi, “The HITRAN molecular spectroscopic database and HAWKS (HITRAN atmospheric workstation): 1996 edition,” J. Quant. Spectrosc. Radiat. Transfer 60, 665–710 (1998). [CrossRef]
  18. S. A. Clough, F. X. Kneizys, R. W. Davies, “Line shape and the water continuum,” Atmos. Res. 23, 229–241 (1989). [CrossRef]
  19. F. Thibault, V. Menoux, R. Le Doucen, L. Rosenmann, J.-M. Hartmann, Ch. Boulet, “Infrared collision-induced absorption by O2 near 6.4 μm for atmospheric applications: measurements and empirical modeling,” Appl. Opt. 36, 563–567 (1997). [CrossRef] [PubMed]
  20. W. J. Lafferty, A. M. Solodov, A. Weber, Wm. Bruce Olsen, J.-M. Hartmann, “Infrared collision-induced absorption by N2 near 4.3 μm for atmospheric applications: measurements and empirical modeling,” Appl. Opt. 35, 5911–5917 (1996). [CrossRef] [PubMed]
  21. S. De Souza-Machado, L. L. Strow, D. Tobin, S. E. Hannon, “Improved atmospheric radiance calculations using P/R-branch line mixing,” in Satellite Remote Sensing of Clouds and Atmosphere IV, J. E. Russell, ed., Proc. SPIE3867, 188–195 (1999).
  22. W. G. Planet, “Data extraction and calibration of TIROS-N/NOAA radiometers,” NOAA Technical Memo NESS 107 (National Oceanic and Atmospheric Administration, Washington, D.C., 1988).
  23. Q. Liu, J. Schmetz, “On the problem of an analytical solution to the diffusivity factor,” Beitr. Phys. Atmosph. 61, 23–291988.
  24. A. P. McNally, “A note on the occurance of cloud in meteorologically sensitive areas and the implications for advanced infrared sounders,” Q. J. R. Meteorol. Soc. 128, 2551–2556 (2002). [CrossRef]

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