A long-standing enigma in oceanography is the process in which nutrients are supplied to the sunlit zone of the low nutrient regions of the ocean. In this work, we present one approach for quantifying the physical supply of nitrate to the euphotic zone in the Sargasso Sea through the use of gas tracers. We find that the nitrate supplied is more than enough to support the rates of net community production (balance of photosynthesis respiration) observed.

Terrestrial carbon feedbacks are a large uncertainty in climate change. We separate modeled feedback responses into those governed by changed carbon inputs (productivity) and changed outputs (turnover). The disaggregated responses show that both are important in controlling inter-model uncertainty. Interactions between productivity and turnover are also important, and research must focus on these interactions for more accurate projections of carbon cycle feedbacks.

We have reconstructed maps of air-sea CO2 fluxes at high resolution (4 km) in the offshore Benguela region using sea surface temperature and ocean colour data and CarbonTracker CO2 fluxes data at low resolution (110 km). The inferred representation of pCO2 improves the description provided by CarbonTracker, enhancing small-scale variability. We find that the resolution, as well as the inferred pCO2 data itself, is closer to in situ measurements of pCO2.