The study of light propagation, absorption and scattering in marine water. It connects spectral measurements to dissolved material, suspended particles and biological activity.
The illuminated region of a water body. In ecological usage its photosynthetically usable part is often identified with the euphotic zone; the operational light threshold must be stated.
The upper water interval with sufficient light for substantial photosynthesis. A common operational lower boundary is the euphotic depth at 1% of surface photosynthetically active radiation.
The depth of a chosen light threshold, commonly 1% of just-below-surface photosynthetically active radiation. It depends on spectral attenuation and is not a universal species-specific compensation depth.
The spectral distribution of light emerging from a water body, determined by absorption and scattering by water, dissolved material, particles and sometimes the bottom. It supports remote inference of biological and optical properties.
The logarithmic rate at which downwelling spectral irradiance decreases with depth. It depends on absorption, scattering and the angular light field, rather than equaling the absorption coefficient.
Inference of chlorophyll a concentration from measured optical signals. Simple blue/green ratios rely on assumptions about covarying absorbers and scatterers; coastal mixtures can violate those assumptions.
The rate per unit path length at which light is scattered into the backward hemisphere. It influences water-leaving radiance and must be distinguished from the absorption coefficient.
The ratio of water-leaving radiance to incident downwelling irradiance just above the surface. It depends on both absorption and backscattering and has units of inverse steradian.
An optically defined non-phytoplankton particle category, including detritus and suspended mineral material. Its absorption is often strongest in the blue; scattering can also strongly affect remote-sensing reflectance.
The light-absorbing fraction of dissolved organic material. Its visible absorption commonly decreases approximately exponentially from blue to red, and can confound chlorophyll retrieval.
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Ocean optics is a field of study that focuses on the interaction of light with water and its constituents, including phytoplankton, dissolved organic matter, sediments, and other materials present in the ocean. It encompasses various scientific disciplines, including physics, chemistry, and biology, to understand how light behaves in marine environments. Key aspects of ocean optics include: 1. **Light Propagation**: This involves understanding how light penetrates the ocean's surface, scattering and absorbing as it travels through water.