# ``chlorophyll_a``
## Properties
:dimensions: N_PROF, N_LEVELS
:dtype: float64
## Default Attributes
| Attribute | Value |
|-----|-----|
|``whp_name`` | ``CHLORA`` |
|``whp_unit`` | ``UG/L`` |
|``standard_name`` | ``mass_concentration_of_chlorophyll_a_in_sea_water`` |
|``units`` | ``ug/l`` |
|``C_format`` | ``%9.2f`` |
|``C_format_source`` | ``database`` |
## Description
chlorophyll-a. 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.