Carbon, oxygen and biological productivity in the Southern Ocean in and out the Kerguelen plume: CARIOCA drifter results

Abstract

Abstract. The Kerguelen Plateau region in the Indian sector of the Southern Ocean supports annually a large-scale phytoplankton bloom which is naturally fertilized with iron.

A multi-method autonomous assessment of primary productivity and export efficiency in the springtime North Atlantic

“…However, even in this case, assuming moderate daytime phytoplankton respiration rates (≤ 30 % of GPP), GOP / GPP during their study was > 2.5, which is in agreement with our estimates. It is also worth noting that related studies comparing diel cycles in O 2 and pCO 2 measurements (Johnson, 2010;Merlivat et al, 2015), both of which include the effects of DOC production, have found ratios of daytime oxygen production to carbon production that are within the expected range of 1-1.45. These results provide further support for diel-cycle-based O 2 production and the hypothesis that DOC production may drive the high GOP / GPP observed in this and other studies (Bender et al, 1992;Hamme et al, 2012).…”

“…Because diurnal variability in b bp can be estimated from geostationary satellites (Neukermans et al, 2012), the ability to accurately estimate GPP from b bp diel cycles would be extremely valuable. While ship-based measurements from NAB08 show that b bp and c p were equally well correlated with POC over the May cruise , the poor matchups we find between GPP Chl a and GPP bbp suggest that diel changes are present in POC / b bp and can cause strong, consistent bias in GPP bbp .…”

Simultaneous CO2 and O2 Supersaturation in Waters of Southern Patagonia? The Importance of Evaluating Overall Carbonate System Parameters Uncertainty and External Consistency. A Comment to Vargas et al., 2018

“…For production of carbohydrates, the photosynthetic quotient is 1.0, which is identical to the inverse processes, respiration (Falkowski & Raven, 1997). This fundamental equivalence drives the inverse relationship between dissolved oxygen (DO) and dissolved inorganic carbon (C T ) observed in the productive coastal ocean, although it may be modified by a wide range of processes and factors (e.g., Merlivat et al, 2015;Thomas, 2002).Well ventilated-macronutrient rich-oceanic sub-Antarctic Surface Water, that floods the inner basins of the Patagonian archipelago, has O 2 and CO 2 levels near the ones expected by equilibration with the atmosphere (Carter et al, 2009;Sarmiento et al, 2004;Torres et al, 2011). Therefore, intense spring primary productivity within inner waters tend to drop pCO 2 far below the atmospheric levels, while increasing DO above its saturation level.…”

“…For production of carbohydrates, the photosynthetic quotient is 1.0, which is identical to the inverse processes, respiration (Falkowski & Raven, 1997). This fundamental equivalence drives the inverse relationship between dissolved oxygen (DO) and dissolved inorganic carbon (C T ) observed in the productive coastal ocean, although it may be modified by a wide range of processes and factors (e.g., Merlivat et al, 2015;Thomas, 2002).…”

A Surface Ocean CO2 Reference Network, SOCONET and Associated Marine Boundary Layer CO2 Measurements

“…Research questions relating to climate and ecosystem changes benefit from sustained observations. There are a series of research questions that can, in part, be addressed with data from SOCONET platforms including quantifying the physical parameters impacting air-sea CO 2 exchange (e.g., Zappa et al, 2004); the impact of the biological pump on surface ocean CO 2 levels (e.g., Merlivat et al, 2015); feedbacks of calcifying organisms on surface water CO 2 (e.g., Frankignoulle et al, 1994); the control and changes of biogeochemical process (e.g., Schneider and Müller, 2018); and the response of surface ocean CO 2 levels to changes in atmospheric forcing (e.g., Arora et al, 2013). The latter is of great importance in the socio-economic arena to assess the efficacy of fossil fuel CO 2 reductions in meeting climate accords (Peters et al, 2017) that will require observational validation.…”