Abstract
Commonly we see the diffuse attenuation coefficient of downwelling irradiance (Kd) expressed as a sum of the contributions of various constituents. We show here that, both theoretically and numerically, because Kd is an apparent optical property, this approach is not consistent with radiative transfer. We further advocate the application of models of Kd developed in past decades that are not only consistent with radiative transfer but also provide more accurate estimates, in particular for coastal turbid waters.
Highlights
Solar radiation is the energy source for the entire earth system
Since the variation of Ed(0−) is independent of water properties (except extremely turbid waters where the enhanced upwelling flux will result in significant contributions to Ed(0−) due to internal reflection), it is imperative to describe the variation of Kd for various aquatic environments when quantifying the impact of water constituents on the heat budget (Morel and Antoine, 1994; Ohlmann et al, 2000), the feedback of oceanic systems on climate changes (Rochford et al, 2001; Gnanadesikan and Anderson, 2009), as well as the vertical variation of primary production (Sathyendranath and Platt, 1995)
The contributions of colored dissolved organic matter (CDOM) and organic detritus are considered as co-varying with phytoplankton, and lumped into the Kbio term
Summary
AOPs Are Not Additive: On the Biogeo-Optical Modeling of the Diffuse Attenuation Coefficient. We see the diffuse attenuation coefficient of downwelling irradiance (Kd) expressed as a sum of the contributions of various constituents. Both theoretically and numerically, because Kd is an apparent optical property (AOP), this approach is not consistent with radiative transfer. We further advocate the application of models of Kd developed in past decades that are consistent with radiative transfer and provide more accurate estimates, in particular for coastal turbid waters
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
