Calcium Carbonate Fluxes in the Atlantic Ocean through Sediment Trap Particulate Inorganic and Organic Carbon Data

Abstract:

Over the summer during my internship with the Partnership Education Program (PEP), I studied particulate flux data in the Atlantic Ocean, the second largest ocean basin. Calcium carbonate is an important portion of the carbon cycle because its dissolution buffers acidification due to anthropogenic CO2 emissions. Ocean acidification depletes ocean carbonate ion; a key shell-building block in sea water, ultimately harming a variety of marine species (such as, but not limited to coccolithophores, foraminifera, pteropods, and reef-building corals). My research is based around why there is variability of calcium carbonate flux in the Atlantic Ocean basin. The key components of my research are focused on the particulate organic carbon (POC) and particulate inorganic (PIC) carbon flux in a global compilation of

sediment trap data (Mouw 2016). For the initial ratio of PIC to CaCO3 I could see that PIC is relatively high at the surface from 200m to 1000m and remains consistently high even below the 1000m depth.The depth profiles of PIC and POC fluxes are high at the surface, but decrease rapidly with depth, suggesting that both organic carbon and PIC are remineralized in the shallow ocean. Analyzing the plot created for PIC to POC ratio shows that they are both high in number between 200 and 1200m, but as PIC depletes so does POC, and both remain consistent at the lower levels starting at 1400m. The PIC to POC flux ratio is variable but relatively constant with depth below about 1000m, suggesting similar rates of organic carbon and PIC remineralization. When I separated the PIC and POC fluxes on different plots PIC showed me that it remineralizes consistently at the same level from the surface to the deeper portions of the ocean at 4800m. The POC flux shows me similarities with numbers being high at the surface between 200m and 1000m, but after 1000m the POC starts to remineralize at a faster rate than PIC. This analysis of PIC and POC is important due to the fact that it shows new linkages between the flux of POC and PIC in the Atlantic, suggesting a strong relationship between calcification and organic carbon production and remineralization.