Mapping the Thickness of Pancake Ice Using Ocean Wave Dispersion in SAR Imagery

  • P. Wadhams
  • F. Parmiggiani
  • G. de Carolis
  • M. Tadross
Conference paper


During the early to midwinter period pancake ice is a major component of the Antarctic sea ice cover, occupying a belt extending 200-300 km from the outer ice edge with an area of about 6 million km2. Experience in the Arctic suggests that the sea ice thickness in this region can be mapped by monitoring the penetration of ocean waves into it. Spectral analysis of subscenes from ERS-2 synthetic aperture radar (SAR) images yields the wavelength and direction of the principal spectral component both outside and inside the ice cover. There is a change of wavelength at the ice edge associated with a change in the wave dispersion, which can be quantitatively related to the thickness of the ice. The analysis is complex because the true wave spectrum must be retrieved from the SAR spectrum, which involves an inversion technique requiring a “first-guess” spectrum. The analysis technique is described, and the wave theory which predicts the change in wavelength. Experience in the Chukchi Sea and especially in the Odden ice tongue in the Greenland Sea is reviewed. Preliminary data from the Ross Sea have been analysed, yielding principal wave components, but the ambient wavelength was too long for the effect of ice to be detectable. The next application will be to the outer ice edge, when midwinter data from this region are available at the end of the current season.


Synthetic Aperture Radar Wave Spectrum Synthetic Aperture Radar Imagery Directional Wave Spectrum Synthetic Aperture Radar Spectrum 
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  1. 1.
    Wadhams P, LangeMA, Ackley SF (1987) The ice thickness distribution across the Atlantic sector of the Antarctic Ocean in midwinter. J Geophys Res 92 (C13): 14535–14552Google Scholar
  2. 2.
    Lange MA, Ackley SF, Dieckmann GS, Eicken H, Wadhams P (1989) Development of sea ice in the Weddell Sea. Ann Glaciol 12: 92–96Google Scholar
  3. 3.
    Martin S, Kauffman P (1981) A field and laboratory study of wave damping by grease ice. J Glaciol 27 (96): 283–313Google Scholar
  4. 4.
    Zwally HJ, Comiso JC, Parkinson CL, Campbell WJ, Carsey FD, Gloersen P (1983) Antarctic Sea Ice 1973–1976: satellite passive-microwave observations. NASA, Washington, Report SP-459Google Scholar
  5. 5.
    Wadhams P, Squire VA, Ewing JA, Pascal RW (1986) The effect of the marginal ice zone on the directional wave spectrum of the ocean. J Phys Oceanogr 6 (2): 358–376CrossRefGoogle Scholar
  6. 6.
    Wadhams P, Squire VA, Goodman DJ, Cowan AM, Moore SC (1988) The attenuation rates of ocean waves in the marginal ice zone. J Geophys Res 93 (C6): 6799–6818CrossRefGoogle Scholar
  7. 7.
    Wadhams P (1986) The seasonal ice zone. In: Untersteiner N (ed.) The geophysics of sea ice. Plenum Press, New York, 825–991Google Scholar
  8. 8.
    Peters AS (1950) The effect of a floating mat on water waves. Communs. Pure Appl. Math 3: 319354Google Scholar
  9. 9.
    Weitz M, Keller JB (1950) Reflection of water waves from floating ice in water of finite depth. Communs Pure Appl Math 3 (3): 305–318CrossRefGoogle Scholar
  10. 10.
    Keller JB, Weitz M (1953) Reflection and transmission coefficients for waves entering or leaving an icefield. Communs Pure Appl Math 6 (3): 415–417CrossRefGoogle Scholar
  11. 11.
    Shapiro A, Simpson LS (1953) The effect of a broken icefield on water waves. Trans Am Geophys U 34 (1): 36–42Google Scholar
  12. 12.
    Wadhams P, Holt B (1991) Waves in frazil and pancake ice and their detection in Seasat synthetic aperture radar imagery. J Geophys Res 96 (C5): 8835–8852CrossRefGoogle Scholar
  13. 13.
    Newyear K, Martin S (1997) A comparison of theory and laboratory measurements of wave propagation and attenuation in grease ice. J Geophys Res 102 (C11): 25091–25099CrossRefGoogle Scholar
  14. 14.
    Alpers WR, Ross DB, Rufenach CL (1981) On the detectability of ocean surface waves by real and synthetic aperture radar. J Geophys Res 86: 6481–6498CrossRefGoogle Scholar
  15. 15.
    Hasselmann K, Raney RK, Plant WJ, Alpers WR, Shuchman RA, Lyzenga DR, Rufenach CL, Tucker MJ (1985) Theory of synthetic aperture radar ocean imaging: a MARSEN view. J Geophys Res 90: 4659–4686CrossRefGoogle Scholar
  16. 16.
    Hasselmann K, Hasselmann S (1991) On the nonlinear mapping of an ocean wave spectrum into a synthetic aperture radar image spectrum and its inversion. J Geophys Res 96(C6):10, 713–10, 729Google Scholar
  17. 17.
    Hasselmann S, Brüning C, Hasselmann K, Heimbach P (1996) An improved algorithm for the retrieval of ocean wave spectra from synthetic aperture radar image spectra. J Geophys Res 101: 16615–16629CrossRefGoogle Scholar
  18. 18.
    Wadhams P, Comiso JC, Prussen E, Wells S, Brandon M, Aldworth E, Viehoff T, Allegrino R, Crane DR (1996) The development of the Odden ice tongue in the Greenland Sea during winter 1993 from remote sensing and field observations. J Geophys Res 101(C8):18, 213–18, 235Google Scholar
  19. 19.
    Wadhams P, De Carolis G, Parmiggiani F, Tadross M (1997) Wave dispersion by frazil-pancake ice from SAR imagery. Proc. IGARSS’97, Singapore, Aug. 1997, 41–43Google Scholar
  20. 20.
    Wadhams P, Parmiggiani F, Tadross M (1995) Wave spectra of SAR imagery of the Odden Ice Tongue. Proc. IGARSS’95, Florence, July 1995, I, 630–633Google Scholar

Copyright information

© Springer-Verlag Italia, Milano 1999

Authors and Affiliations

  • P. Wadhams
    • 1
  • F. Parmiggiani
    • 2
  • G. de Carolis
    • 3
  • M. Tadross
    • 1
  1. 1.Scott Polar Research InstituteUniversity of CambridgeCambridgeUK
  2. 2.IMGA-CNRBolognaItaly
  3. 3.ITIS-CNRMateraItaly

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