A complex field such as oceanography tends to be subject to two opposite appr0aches. The first is the descriptive, in which several quantities are measured simultaneously and their inter-relationships derived by some sort of statistical method. The other approach is the synthetic one, in which a few reasonable although perhaps oversimplified assumptions are laid down, these serving as a basis for mathematical derivation of relationships.
Riley, Gordon A.. 1946. "Factors controlling phytoplankton populations on Georges Bank." Journal of Marine Research 6, (1). https://elischolar.library.yale.edu/journal_of_marine_research/624