The saturation status of calcium carbonate forms was calculated as part of the CDRmare RETAKE project effort to assess potentials and impacts for using alkalinity enhancement to enhance the capture of atmospheric carbon dioxide (CO2). Therefore, this data set is a compilation of carbonate system parameters measured during the monitoring cruises of the Leibniz Institute for Baltic Sea Research Warnemünde (IOW) in the Baltic Sea from 2003 to 2023. Ancillary data was retrieved using the IOW's ODIN2 data tool accordingly. The following permanent link allows one to search and extract the data using our settings: https://odin2.io-warnemuende.de/957-0489-676. We paired the carbonate and ancillary (nutrient and hydrogen sulfide, H2S, data) data by selecting the respective cruise, station, timestamp, and depth. Next, we calculated the calcite and aragonite saturation state and other carbonate system parameters using the measured parameters always when two carbonate-system parameters were available. For these calculations, we used CO2SYS v.3.1.2 script for MATLAB (Sharp et al., 2023; van Heuven et al., 2011; Lewis and Wallace, 1998) with the following dissociation constants settings: K1 and K2 of Waters, Millero, & Woosley (2014), KSO4 of Dickson (1990), KF of Perez & Fraga (1987), and TB of Uppström (1979). Propagated uncertainty was calculated using the errors script for MATLAB CO2SYS of Orr et al. (2018) and applying the respective errors: total alkalinity (AT) = 4 µmol/kg, total inorganic dissolved carbon (CT) = 2 µmol/kg, pH = 0.005 (Total), phosphate (PO4) = 3.8%, silicate (SiO4) = 4.6%, and ammonium (NH4) = 9.2%. All carbonate system parameters are presented under 25°C and 0 atm conditions.

Data originator: Leibniz Institute for Baltic Sea Research Warnemünde, Germany