Baltic Sea 2023 R/V Skagerak Cruise Data (CTD Stations; Radium; DSi)

Data were collected across the Baltic Sea in surface water and the bottom water column in September 2023. Dataset consists of four files: (1) Baltic2023_Samples_Data_V2.csv (Sample Data) Column Names and Description: Sample_ID: Sample name, with the following scheme, BS_STN_DEP where STN is the three-digit station number and DEP is the depth above the seafloor in meters. Station: Station number Type: SURF (collected from surface water, ~4 m depth), CTD (collected from bottom waters via CTD rosette) Lat: Latitude of station. Long: Longitude of station. Datetime_UTC: Date and time of sampling in UTC. Depth_m: Sample depth (m). Measured with Sea-Bird SBE 911. dist_along_track_km: Distance along cruise track (km). Salinity: Water column salinity. Measured with Sea-Bird SBE 911. Temp_C: Water column temperature (°C). Measured with Sea-Bird SBE 911. DO_per: Dissolved oxygen in %. Measured with Sea-Bird SBE 911. Rho_kg_m3: Water column density (kg/m^3), calculated from CTD data using the the Thermodynamic Equation of Seawater 2010 (TEOS-10) equation of state and the Gibbs Seawater (GSW) Oceanographic Toolbox in Python (McDougall and Barker, 2011). Ra224_dpm_100L: 224Ra concentration in dpm/100 L. Measured with a RaDeCC system. Ra224_dpm_100L_unc: 224Ra concentration analytical uncertainty in dpm/100 L via error propogation. DSi_umol_L: Dissolved silicate concentration in µmol/L. Measured with a SEAL AA500 AutoAnalyzer. (2) Baltic2023_CTD_data_V2.csv (CTD Data) Processed and cleaned CTD profiles for all stations. Column Names and Description: Station: Station number Pressure_dbar: Pressure in decibars. Measured with Sea-Bird SBE 911. Temperature_C: Water column temperature (°C). Measured with Sea-Bird SBE 911. Depth_m: Sample depth (m). Measured with Sea-Bird SBE 911. Salinity: Water column salinity. Measured with Sea-Bird SBE 911. DO_per: Dissolved oxygen in %. Measured with Sea-Bird SBE 911. Lat: Latitude of station. Long: Longitude of station. Rho_kg_m3: Water column density (kg/m^3), calculated from CTD data using the the Thermodynamic Equation of Seawater 2010 (TEOS-10) equation of state and the Gibbs Seawater (GSW) Oceanographic Toolbox in Python (McDougall and Barker, 2011). (3) Baltic2023_Raeff_data_V2.csv (Radium efficiency Data) Data required to compute radium efficiency. For more info, please see accompanying manuscript. _UP refers to the first/most upstream/first MnO2 fiber and _DOWN refers to the last/most downstream/second MnO2 fiber aligned in a series. Column Names and Description: Sample: Sample name. TOT_CNTS_dpm_UP: Total counts in dpm in UP fiber. Measured with a RaDeCC system. TOT_CNTS_dpm_DOWN: Total counts in dpm in DOWN fiber. Measured with a RaDeCC system. Ra224_dpm_100L_UP: 224Ra concentration in dpm/100 L in UP fiber. Measured with a RaDeCC system. Ra224_dpm_100L_UP_unc: 224Ra concentration uncertainty in dpm/100 L in UP fiber. Ra224_dpm_100L_DOWN: 224Ra concentration in dpm/100 L in DOWN fiber. Measured with a RaDeCC system. Ra224_dpm_100L_DOWN_unc: 224Ra concentration uncertainty in dpm/100 L in DOWN fiber. (4) Baltic2023_radecc_data_V2.csv (Raw RaDeCC Data) Data measured by the RaDeCC and other underlying data required for radium calculations. Column Names and Description: Sample: Sample name. Coll_date_CEST: Date of sample collection in CEST. Format: YYYY-MM-DD. Coll_time_CEST: Time of sample collection in CEST. Format: 24:MM:SS. Vol_L: Sample water volume passed through the MnO2 coated fiber (L). Bkg_cpm: Total background counts in counts per minute measured on the RaDeCC prior to analysis. Count_date_CEST: Date sample run started on RaDeCC in CEST. Format: YYYY-MM-DD. Count_time_CEST: Time sample run started on RaDeCC in CEST. Format: 24:MM:SS. Count_min: Duration of sample counting time on the RaDeCC in minutes. 219_cpm: Counts per minute in the 219 channel on the RaDeCC. 220_cpm: Counts per minute in the 220 channel on the RaDeCC. Total_cpm: Counts per minute in the total channel on the RaDeCC. exRa224_dpm_100L: Final sample 224Ra concentration in dpm/100 L. Measured with a RaDeCC system. exRa224_unc_dpm_100L: Final 224Ra concentration uncertainty in dpm/100 L.