Journal of Atmospheric Chemistry

, Volume 58, Issue 3, pp 219–235 | Cite as

Photobleaching of chromophoric dissolved organic matter (CDOM) in rainwater

  • Robert J. KieberEmail author
  • Joan D. Willey
  • Robert F. Whitehead
  • Seth N. Reid


Significant photodegradation of chromophoric dissolved organic matter (CDOM) in rainwater was observed after exposure to simulated sunlight. Fluorescence excitation emission spectra (EEMS) of precipitation revealed the presence of four major peaks all of which degraded upon photolysis with the greatest loss in the region characteristic of marine CDOM. Photobleaching of absorbance also occurred in the wavelength region between 250 and 375 nm with the greatest loss of absorbance in the upper end of the UV-A region near 275 nm. There was a strong positive correlation between absorbance loss and total integrated fluorescence loss suggesting these optical properties and the degree to which they are photobleached in rainwater are directly related. The quantum yield of CDOM photodegradation in rainwater decreased dramatically with increasing wavelength and decreasing energy of incoming radiation with the average quantum yield at 325 nm approximately an order of magnitude greater than at 460 nm. The similarity of photolytic response between rainwater and Cape Fear estuarine CDOM indicates that some fraction of the compounds that make up rainwater CDOM may be derived from surface sources and/or that the processes that produce or modify humic-like substances in the atmosphere result in similar types of compounds as non-atmospheric processes.


Chromophoric dissolved organic matter CDOM Photochemistry Rain 



This work was supported by NSF Grant ATM-0342420. The Marine and Atmospheric Chemistry Research Laboratory at UNC Wilmington assisted with sampling and analyses.


  1. Blough, N.V., Green, S.A.: In Spectroscopic Characterization and Remote Sensing of Nonliving Organic Matter. Wiley (1995)Google Scholar
  2. Bruland, K.W.: Oceanographic distributions of cadmium, zinc, nickel and copper in the North Pacific, Earth Planet. Sci. Lett. 47, 176–198 (1980)Google Scholar
  3. Bruland, K.W., Franks, R.P., Knauer, G.A., Martin, J.H.: Sampling and analytical methods for the determination of copper, cadmium, zinc, and nickel at the nanogram per liter level in seawater. Anal. Chim. Acta 105, 223–245 (1979)CrossRefGoogle Scholar
  4. Chin, Y.P., Aiken, G.R., O’Loughlin, E.: Molecular weight polydispersity and spectroscopic properties of aquatic humic substances. Environ. Sci. Technol. 28, 1853–1858 (1994)CrossRefGoogle Scholar
  5. Coble, P.G.: Characterization of marine and terrestrial DOM in seawater using excitation-emission matrix spectroscopy. Mar. Chem. 51, 325–346 (1996)CrossRefGoogle Scholar
  6. Coble, P.G., Schultz, C.A., Mopper, K.: Fluorescence contouring analysis of DOC Intercalibration Experiment samples: a comparison of techniques. Mar. Chem. 41, 175–178 (1993)CrossRefGoogle Scholar
  7. Coble, P.G., Del Castillo, C.E., Avril, B.: Distribution and optical properties of CDOM in the Arabian Sea during the 1995 Southwest Monsoon. Deep-Sea Res. II 45, 2195–2223 (1998)CrossRefGoogle Scholar
  8. Cooper, W.J., Zika, R.G., Petasne, R.G., Fischer, A.M.: In: MacCarthy P. and Suffett I. H. (eds.) Sunlight Induced Photochemistry of Humic Substances in Natural Waters: Major Reactive Species. American Chemical Society (1989)Google Scholar
  9. De Haan, H.: Solar UV-light penetration and photodegradation of humic substances in peaty lake water. Limnol. Oceanogr. 38, 1072–1076 (1993)Google Scholar
  10. Decesari, S., Facchini, M.C., Fuzzi, S., McFiggans, G.B., Coe, H., Bower, K.N.: The water soluble organic component of size segregated aerosol, cloud water and wet deposition from Jeju Island during ACE Asia. Atmos. Environ. 39, 211–222 (2005)CrossRefGoogle Scholar
  11. Del Castillo, C.E., Coble, P.G.: Analysis of the optical properties of the Orinoco River Plume by absorption and fluorescence spectroscopy. Mar. Chem. 66, 35–51 (1999)CrossRefGoogle Scholar
  12. Del Vecchio, R., Blough, N.V.: Photobleaching of chromophoric dissolved organic matter in natural waters: kinetics and modeling. Mar. Chem. 78, 213–253 (2002)CrossRefGoogle Scholar
  13. Del Vecchio, R., Blough, N.V.: On the origin of the optical properties of humic substances. Environ. Sci. Technol. 38, 3885–3891 (2004)CrossRefGoogle Scholar
  14. Facchini, M.C., Decesari, S., Mircea, M., Fuzzi, S., Loglio, G.: Surface tension of atmospheric wet aerosol and cloud/fog droplets in relation to their organic carbon content and chemical composition. Atmos. Environ. 34, 4853–4857 (2000)CrossRefGoogle Scholar
  15. Graber, E.R., Rudich, Y.: Atmospheric HULIS: how humic like are they? A comprehensive and critical review. Atmos. Chem. Phys. 6, 729–753 (2006)CrossRefGoogle Scholar
  16. Kieber, R.J., Williams, K.H., Willey, J.D., Skrabal, S.A., Avery, G.B.: Iron speciation in coastal rainwater: concentration and deposition to seawater. Mar. Chem. 73, 83–95 (2001)CrossRefGoogle Scholar
  17. Kieber, R.J., Hardison, D.R., Whitehead, R.F., Willey, J.D.: Photochemical production of Fe(II) in rainwater. Environ. Sci. Technol. 37, 4610–4616 (2003a)CrossRefGoogle Scholar
  18. Kieber, R.J., Willey, J.D., Avery, G.B.: Temporal variability of rainwater iron speciation at the Bermuda Atlantic Time Series Station. J. Geophys. Res. 108, 1–7 (2003b)CrossRefGoogle Scholar
  19. Kieber, R.J., Skrabal, S.A., Smith, C., Willey, J.D.: Redox speciation of copper in rainwater: temporal variability and atmospheric deposition. Environ. Sci. Technol. 38, 3587–3594 (2004)CrossRefGoogle Scholar
  20. Kieber, R.J., Skrabal, S.A., Smith, B., Willey, J.D.: Organic complexation of Fe(II) and its impact on the redox cycling of iron in rain. Environ. Sci. Technol. 39, 1576–1583 (2005)CrossRefGoogle Scholar
  21. Kieber, R.J., Whitehead, R.F., Willey, J.D., Reid, S., Seaton, P.J.: Chromophoric dissolved organic matter (CDOM) in rainwater collected in southeastern North Carolina, USA. J. Atmos. Chem. 54, 21–41 (2006)CrossRefGoogle Scholar
  22. Kirk, J.T.O.: In Light and Photosynthesis in Aquatic Ecosystems. Cambridge University Press, Cambridge (1994)Google Scholar
  23. Kiss, G., Tombacz, E., Hannsson, H.C.: Surface tension effects of humic like substances in the aqueous extract of tropospheric fine aerosol. J. Atmos. Chem. 50, 279–294 (2005)CrossRefGoogle Scholar
  24. Miller, W.L., Zepp, R.G.: Photochemical production of dissolved inorganic carbon from terrestrial organic matter: significance to the oceanic carbon cycle. Geophys. Res. Lett. 22, 417–420 (1995)CrossRefGoogle Scholar
  25. Miller, W.L., Moran, M.A., Sheldeon, W.M., Zepp, R.G., Opsahl, S.: Determination of apparent quantum yield spectra for the formation of biologically labile photoproducts. Limnol. Oceanogr. 47, 343–352 (2002)CrossRefGoogle Scholar
  26. Mopper, K., Zhuo, X.: Hydroxyl radical photoproduction in the sea and its potential impact on marine processes. Science 250, 661–664 (1990)CrossRefGoogle Scholar
  27. Moran, M.A., Sheldeon, W.M., Zepp, R.G.: Carbon loss and optical property changes during long term photochemical and biological degradation of estuarine dissolved organic matter. Limnol. Oceanogr. 45, 1254–1264 (2000)CrossRefGoogle Scholar
  28. Topol, L.E., Levon, M., Flanagan, J., Schwall, R.J., Jackson, A.E.: Quality Assurance Management for Precipitation Systems. Research Triangle Park, North Carolina, Environmental Protection Agency (1985)Google Scholar
  29. Tzortziou, M., Osburn, C.L., Neale, P.J.: Photobleaching of dissolved organic material from a tidal marsh–estuarine system of the Chesapeake Bay. Photochem. Photobiol. 83, 782–792 (2007)CrossRefGoogle Scholar
  30. Willey, J.D., Kieber, R.J., Eyman, M.S., Avery, G.B.: Rainwater dissolved organic carbon: concentrations and global flux. Glob. Biogeochem. Cycles 14, 139–148 (2000)CrossRefGoogle Scholar
  31. Willey, J.D., Whitehead, R.F., Kieber, R.J., Hardison, D.R.: Oxidation of Fe(II) in rainwater. Environ. Sci. Technol. 39, 2579–2585 (2005)CrossRefGoogle Scholar
  32. Witt, M., Skrabal, S.A., Kieber, R.J., Willey, J.D.: Copper complexation in coastal rainwater in southeastern USA. Atmos. Environ. 41, 3619–3630 (2007a)CrossRefGoogle Scholar
  33. Witt, M., Skrabal, S.A., Kieber, R.J., Willey, J.D.: Photochemistry of Cu complexed with chromophoric dissolved organic matter: implications for Cu speciation in rainwater. J. Atmos. Chem. 58(2), 89–109 (2007b)CrossRefGoogle Scholar
  34. Zepp, R.G., Sheldeon, W.M., Moran, M.A.: Dissolved organic fluorophores in southeastern US coastal waters: correction method for eliminating Raleigh and Raman scattering peaks in excitation emission matricies. Mar. Chem. 89, 15–36 (2004)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Robert J. Kieber
    • 1
    Email author
  • Joan D. Willey
    • 1
  • Robert F. Whitehead
    • 1
  • Seth N. Reid
    • 1
  1. 1.Department of Chemistry and BiochemistryUniversity of North Carolina WilmingtonWilmingtonUSA

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