On mathematical simulation of a pelagic ecosystem in tropical waters of the ocean

Consideration is given to a finite-difference model of functioning of a pelagic community inhabiting the upper 0 to 200 m layer of the tropical waters of the ocean. The model was developed on the basis of original data, obtained mainly on the 44th cruise of the R.V. Vityaz in the western Equatorial Pacific Ocean. Changes in the system are studied in time (up to 100 days, with 1 day intervals) and in depth (from surface to 200 m depth, with 10 m intervals). The state of the system in the upwelling zone, assumed to be characterized by a homogeneous vertical distribution of all its elements, is regarded as initial. The system then develops with time while it moves with the water flow. The model was realized on a BESM-3M computor. The computations yielded a pattern of changes in time of the biomass of the elements (expressed in calories), and a pattern of their vertical distribution at different instants. The vertical distribution pattern of the major elements of the model shows a rather close correlation with their observed distribution in the ocean at the corresponding instant.