under discussion
Created: 24 May 2024
Proposer: Aurore Biardeau
Proposed Date: 2024-05-13
Change Date: 24 May 2024, 11:43 a.m.
Term: mass_concentration_of_chlorophyll_a_in_sea_water_horizontal_gradient
Unit: mg m-3 km-1
Unit ref:
'Mass concentration' means mass per unit volume and is used in the construction mass_concentration_of_X_in_Y, where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as 'nitrogen' or a phrase such as 'nox_expressed_as_nitrogen'. Chlorophylls are the green pigments found in most plants, algae and cyanobacteria; their presence is essential for photosynthesis to take place. There are several different forms of chlorophyll that occur naturally. All contain a chlorin ring (chemical formula C20H16N4) which gives the green pigment and a side chain whose structure varies. The naturally occurring forms of chlorophyll contain between 35 and 55 carbon atoms. Chlorophyll-a is the most commonly occurring form of natural chlorophyll. The chemical formula of chlorophyll-a is C55H72O5N4Mg.