Assessment of the ultraviolet radiation field in ocean waters from space-based measurements and full radiative-transfer calculations.

Quantitative assessment of the UV effects on aquatic ecosystems requires an estimate of the in-water radiation field. Actual ocean UV reflectances are needed for improving the total ozone retrievals from the total ozone mapping spectrometer (TOMS) and the ozone monitoring instrument (OMI) flown on NASA's Aura satellite. The estimate of underwater UV radiation can be done on the basis of measurements from the TOMS/OMI and full models of radiative transfer (RT) in the atmosphere-ocean system. The Hydrolight code, modified for extension to the UV, is used for the generation of look-up tables for in-water irradiances. A look-up table for surface radiances generated with a full RT code is input for the Hydrolight simulations. A model of seawater inherent optical properties (IOPs) is an extension of the Case 1 water model to the UV. A new element of the IOP model is parameterization of particulate matter absorption based on recent in situ data. A chlorophyll product from ocean color sensors is input for the IOP model. Verification of the in-water computational scheme shows that the calculated diffuse attenuation coefficient Kd is in good agreement with the measured Kd.

[1]  Jay R. Herman,et al.  Earth surface reflectivity climatology at 340–380 nm from TOMS data , 1997 .

[2]  Jay R. Herman,et al.  A model for the assessment of UV penetration into ocean waters from space-based measurements and full radiative transfer calculations , 2003, SPIE Optics + Photonics.

[3]  M. Kahru,et al.  Spectral reflectance and absorption of a massive red tide off southern California , 1998 .

[4]  K. Arrigo,et al.  Global Mapping of Underwater UV Irradiances and DNA-Weighted Exposures using TOMS and SeaWiFS Data Products , 1999 .

[5]  C. Mobley,et al.  Phase function effects on oceanic light fields. , 2002, Applied optics.

[6]  E. Fry,et al.  Visible and near-ultraviolet absorption spectrum of liquid water: comment. , 2000, Applied optics.

[7]  T. I. Quickenden,et al.  The ultraviolet absorption spectrum of liquid water , 1980 .

[8]  A. Morel.  Optical modeling of the upper ocean in relation to its biogenous matter content (case I waters) , 1988 .

[9]  K. Baker,et al.  Optical properties of the clearest natural waters (200-800 nm). , 1981, Applied optics.

[10]  Jay R. Herman,et al.  Problems in assessment of the UV penetration into natural waters from space-based measurements , 2002, SPIE Optics + Photonics.

[11]  Ziauddin Ahmad,et al.  An Iterative Radiative Transfer Code For Ocean-Atmosphere Systems , 1982 .

[12]  André Morel,et al.  Light scattering and chlorophyll concentration in case 1 waters: A reexamination , 1998 .

[13]  T. I. Quickenden,et al.  Visible and near-ultraviolet absorption spectrum of liquid water. , 1999, Applied optics.

[14]  K. Arrigo,et al.  Global mapping of underwater UV irradiances and DNA‐weighted exposures using Total Ozone Mapping Spectrometer and Sea‐viewing Wide Field‐of‐view Sensor data products , 2001 .

[15]  H. Claustre,et al.  Variability in the chlorophyll‐specific absorption coefficients of natural phytoplankton: Analysis and parameterization , 1995 .

[16]  E. Fry,et al.  Absorption spectrum (340-640 nm) of pure water. I. Photothermal measurements. , 1997, Applied optics.

[17]  Michael P. Lesser,et al.  The effects of UV radiation in the marine environment , 2001 .

[18]  S. Maritorena,et al.  Bio-optical properties of oceanic waters: A reappraisal , 2001 .

[19]  E. Fry,et al.  Absorption spectrum (380-700 nm) of pure water. II. Integrating cavity measurements. , 1997, Applied optics.

[20]  H. Claustre,et al.  Optical properties of the “clearest” natural waters , 2007 .

[21]  C. Mobley.  Light and Water: Radiative Transfer in Natural Waters , 1994 .

[22]  H. Gordon.  Can the Lambert‐Beer law be applied to the diffuse attenuation coefficient of ocean water? , 1989 .

[23]  Maria Vernet,et al.  The effects of UV radiation in the marine environment: Index , 2000 .

[24]  Knut Stamnes,et al.  Ultraviolet and visible radiation in the atmosphere-ocean system: a tutorial review of modeling capabilities , 2002 .

[25]  K. Stamnes,et al.  Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media. , 1988, Applied optics.

[26]  James F. Gleason,et al.  Ocean Raman scattering in satellite backscatter UV measurements , 2002 .