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Journal of Oceanography

, Volume 64, Issue 4, pp 561–566 | Cite as

Estimation of the in situ Ultraviolet-A absorption of seawater by a simple irradiance inversion model

  • Takafumi HirataEmail author
Short Contribution

Abstract

An irradiance inversion model to estimate the in situ absorption coefficient of seawater has been developed for the Ultraviolet-A (UVA) wavelength domain. Input parameters are sun angle and the up-and downward planar irradiances measured for at least two depths. The present method does not require seawater to be sampled, and is a discrete wavelength method which returns the absorption coefficient at a given wavelength from the irradiances measured at that wavelength without assuming a spectral shape of any optical properties a priori. Comparison between the model results and spectrophotometric measurements shows that the model is practically useful when cloud cover in the atmosphere is ≤ 50%. According to the present method, measurements of the irradiances enable simultaneous observation of the in situ underwater UVA radiation level and the absorption capacity of bulk seawater using a radiometer.

Keywords

UV absorption irradiance inversion 

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References

  1. Ayers, J. M., J. P. Ivey and R. W. Gillett (1991): Coherence between seasonal cycle of dimethylsulphide, methanesulphonate and sulphate in marine air. Nature, 349, 404–406.CrossRefGoogle Scholar
  2. Brugger, A., D. Slezak, I. Obernosterer and G. J. Herndl (1998): Photolysis of dimethyl sulfide in coastal waters: dependence on substrate concentration, irradiance and DOC concentration. Mar. Chem., 59, 321–331.CrossRefGoogle Scholar
  3. Cantoni, G. L. and D. G. Anderson (1956): Enzymatic cleavage of dimethylpropiothein by Polysiphonia lanosa. J. Biol. Chem., 22, 171–177.Google Scholar
  4. Charlson, R. J., J. E. Lovelock, M. O. Andreae and S. G. Warren (1987): Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate. Nature, 326, 655–661.CrossRefGoogle Scholar
  5. Gordon, H. R. (1991): Absorption and scattering estimates from irradiance measurements: Monte Carlo simulations. Limnol. Oceanogr., 36, 769–777.CrossRefGoogle Scholar
  6. Gordon, H. R. and G. C. Boynton (1997): A radiance-irradiance inversion algorithm for estimating the absorption and backscattering coefficients of natural waters: homogeneous waters. Appl. Opt., 36, 2636–2641.CrossRefGoogle Scholar
  7. Gordon, H. R. and G. C. Boynton (1998): A radiance-irradiance inversion algorithm for estimating the absorption and backscattering coefficients of natural waters: vertically stratified water bodies. Appl. Opt., 37, 3886–3896.CrossRefGoogle Scholar
  8. Hirata, T. and N. K. Højerslev (2008): Relationship between the irradiance reflectance and inherent optical properties of seawater. J. Geophys. Res., 113, C03030, doi:10.1029/2007JC004325.CrossRefGoogle Scholar
  9. Jerlov, N. G. (1976): Marine Optics. Elsevier, Amsterdam.Google Scholar
  10. Kirk, J. T. O. (1994): Estimation of the absorption and scattering coefficients of natural waters by the use of underwater irradiance measurements. Appl. Opt., 33, 3276–3278.CrossRefGoogle Scholar
  11. Leathers, R. A. and N. J. McCormick (1997): Ocean inherent optical property estimation from irradiance. Appl. Opt., d36, 8685–8698.CrossRefGoogle Scholar
  12. Leathers, R. A., C. S. Roesler and N. J. McCormick (1999): Ocean inherent optical property determination from in-water light field measurements. Appl. Opt., 38, 5096–5103.CrossRefGoogle Scholar
  13. Loisel, H., D. Stramski, B. G. Mitchell, F. Fell, V. Fournier-Sicre, B. Lemasle and M. Babin (2000): Estimation of inherent optical properties of natural waters from the irradiance attenuation coefficient and reflectance in the presence of Raman scattering. Appl. Opt., 35, 453–462.Google Scholar
  14. Loisel, H., D. Stramski, B. G. Mitchell, F. Fell, V. Fournier-Sicre, B. Lemasle and M. Babin (2001): Comparison of the ocean inherent optical properties obtained from measurements and inverse modelling. Appl. Opt., 40, 2384–2397.CrossRefGoogle Scholar
  15. McCormick, N. J. and G. E. Rinaldi (1989): Seawater optical property estimation from in situ irradiance measurements. Appl. Opt., 28, 2605–2613.CrossRefGoogle Scholar
  16. Mitchell, B. G. (1990): Algorithms for determining the absorption coefficient for aquatic particulate using the quantitative filter technique. Proc. of SPIE, 1302, 137–148.CrossRefGoogle Scholar
  17. Petzold, T. J. (1972): Volume scattering functions for selected ocean waters, SIO Ref. 72–78, Scripps Institution of Oceanography, San Diego.Google Scholar
  18. Pope, R. M. and E. S. Fry (1997): Absorption spectrum (380–700 nm) of pure water. II. Integrating cavity measurements. Appl. Opt., 36, 8710–8723.CrossRefGoogle Scholar
  19. Prospero, J. M., D. L. Savoie, E. S. Saltzman and A. Larsen (1991): Impact of oceanic source of biogenic sulfur on sulfate aerosol concentrations at Mawson, Antarctica. Nature, 350, 221–223.CrossRefGoogle Scholar
  20. Slezak, D., A. Brugger and G. J. Herndl (2001): Impact of solar radiation on the biological removal of dimethylsulfoniopropionate and dimethylsulphide in marine surface waters. Aquat. Microb. Ecol., 25, 87–97.CrossRefGoogle Scholar
  21. Toole, D. A. and D. A. Siegel (2004): Light-driven cycling of dimethylsulfide (DMS) in the Sargasso Sea: Closing the loop. Geophys. Res. Lett., 31, L09308, doi:10.1029/2004GL019581.Google Scholar
  22. Zaneveld, J. R. V., R. Bartz and J. C. Kitchen (1990): A reflective-tube absorption meter. In Ocean Optics X, ed. by R. W. Spinrad, Proc. SPIE, 1302, 124–136.Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Centre for observation of Air-Sea Interactions and fluXes (CASIX)Plymouth Marine LaboratoryPlymouth, DevonUK

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