The NASA graphs show Net Primary Productivity in kg carbon per square
meter per year. The summary equation for photosynthesis indicates that
one O2 is produced per carbon fixed so it could also be expressed in kg
O2 rather than kg carbon if a conversion factor was used.

I've never heard of an oxygen produced to oxygen consumed ratio. There
is a respiratory quotient, the ratio of CO2 respired to O2 consumed,
that varies depending on the substance being respired. Respiratory
quotient is measured for nonphotosynthetic organisms or
nonphotosynthetic plant parts such as roots.


David R. Hershey