New paper out by @willerstorfi et al. in #GCA documenting the evaluation of planktic foraminiferal Na/Ca as a proxy for ocean salinity using plankton tows, sediment traps, and core tops: https://www.sciencedirect.com/science/article/abs/pii/S0016703723001187?

Take home message: looks like this proxy can be quite complex due to varying Na-bearing phases of the foraminiferal calcite, even though the Na/Ca in some of these phases may be strongly correlated to salinity. The authors conclude instead that due to the effect of [CO₃²⁻], foraminiferal Na/Ca over Cenzoic timescales may be a better proxy for major ion chemistry than salinity changes in the ocean.