A combined procedure of benzalkonium chloride (BAC) addition and filtration was investigated to preserve water samples for radiocarbon analysis of dissolved inorganic carbon (DIC). The results indicated that DIC changes can be effectively suppressed during sample storage for up to 41 weeks. This procedure offers a practical, environmentally friendly alternative to conventional mercury-disinfected methods, effectively water sample preservation samples in aquatic environments.

Quantifying the carbon budget in the ocean is logistically difficult and costly. Specifically, measuring the movement of CO₂ across the air–sea interface requires expensive analyzers. To combat this, our group has developed a low-cost ΔpCO₂ system, called The Sensor for the Exchange of Atmospheric CO₂ with Water (SEACOW). We demonstrate the SEACOW’s ability to capture pCO₂ cycling, provide recommendations for SEACOW field deployments, and provide technical specifications for the SEACOW.

Water isotopes in the ocean trace the freshwater exchanges between the ocean, the atmosphere and the cryosphere, and are used to investigate processes of the hydrological cycle. We illustrate offsets in seawater isotopic composition between different data sets that are larger than the expected variability that one often wants to explore. This highlights the need to share seawater isotopic composition samples dedicated to specific intercomparison of data produced in the different laboratories.

The extent of mankind’s influence on Earth’s climate warrants ocean-studies. A supposed major heat-transporter is the Atlantic Meridional Overturning Circulation (AMOC). As AMOC is a complex nonlinear dynamical system, mathematical models may predict its potential collapse using single parameters like surface temperature. However, physical processes such as (sub-)mesoscale eddy transport and turbulent mixing by internal wave breaking will alter the estimators, so that the AMOC may not collapse.