In this Technical Publication, we describe the model functionality and analyze its application to the seasonal and interannual variations of phytoplankton, nutrients, pCO2 and CO2 concentrations in the eastern subarctic Pacific at Ocean Weather Station P (OWSP, 50 deg. N 145 deg. W). We use a verified one-dimensional ecosystem model, coupled with newly incorporated carbon flux and carbon chemistry components, to simulate 22 years (1958-1980) of pCO2 and CO2 variability at Ocean Weather Station P (OWS P). This relatively long period of simulation verifies and extends the findings of previous studies using an explicit approach for the biological component and realistic coupling with the carbon flux dynamics. The slow currents and the horizontally homogeneous ocean in the subarctic Pacific make OWS P one of the best available candidates for modeling the chemistry of the upper ocean in one dimension. The chlorophyll and ocean currents composite for 1998 illustrates this premise. The chlorophyll concentration map was derived from SeaWiFS data and the currents are from an OGCM simulation (from R. Murtugudde).Signorini, S. and McClain, C. and Christian, J. and Wong, C. S.Goddard Space Flight CenterPHYTOPLANKTON; ANNUAL VARIATIONS; BIOGEOCHEMISTRY; MATHEMATICAL MODELS; MARINE CHEMISTRY; ENVIRONMENT MODELS; CARBON DIOXIDE CONCENTRATION; WEATHER STATIONS; VARIABILITY; SIMULATION; SEA SURFACE TEMPERATURE; REMOTE SENSING; PACIFIC OCEAN; OCEAN CURRENTS; MARINE METEOROLOGY; ECOSYSTEMS...