A three-dimensional model of global biogeochemical cycles (HAMOCC3) is
used to discuss potential explanations for apparent observed deviatio
ns from a basin-wide Redfield ratio. Two examples are given in which m
odel information can be taken to close the gaps of incomplete measurem
ents or data analyses. A third example illustrates how the apparent co
variation between phosphate and alkalinity is created by the circulati
on.