The worlds upwelling regions bring nutrient rich water to the euphotic zone and make up the most primary productive regions in the ocean. While upwelled water's nitrogen concentration is high, evidence shows the micronutrient iron can be limiting. Low iron concentration will inhibit the biological utilization of nitrogen, and prevent the phytoplankton community from fulfilling its productivity potential. Previous studies suggest that iron concentration is dictated from the upwelling coastline's geology and river input, but the system is more complex. From published documents, samples were selected from California's upwelling coastline that were either iron limited or iron replete. These samples were unable to be explained by the traditional model. Sea surface temperature and altimetry maps were developed displaying the complexity of the upwelling system and the samples' source of iron concentration was determined.