Photosynthetic primary production in the sea is one of the main processes occurring in the Earth’s biosphere. It is the first link in the trophic chain  and is thus responsible for supplying ecosystems with energy. The primary production process also releases oxygen. As a result, phytoplankton is one of the principal regulators of the oxygen-carbon dioxide budget and influences the climate by regulating the greenhouse effect in the atmosphere. The vertical distribution of the daily production is given at depths correlated with the depths for which the other parameters are determined using the DESAMBEM model, i.e. 0, 1, 3, 5, 10, 20 m.

The formula enabling one to calculate the total daily primary production at selected depths pp(z) (where z is selected depth) (Woźniak i in., 2008, Woźniak i in, 2007):

$$pp(z)=12*fi(z)*\eta PUR(z)\rightarrow$$

where

$$\eta PUR(z)$$ –

The daily dose of energy absorbed by phytoplankton at depth z

$$fi(z)$$ – The quantum efficiency of photosynthesis at depth z

The value of primary production at selected depths is stated in milligrams of assimilated carbon per cubic metre per day [mg C m^-3 d^-1].

Methodology

The primary production at selected depths in the Baltic is determined using the DESAMBEM model (Woźniak et al., 2008).

Validation

It is assumed that the errors in determining primary production at given depths are the same as in the case of primary production z-=0, that is primary production in the water column.

Links to the parameters in SatBaltic System:

Primary production

Primary production: 0m

Primary production: 1m

Primary production: 3m

Primary production: 5m

Primary production: 10m

Primary production: 20m