CTD data near floating sediment trap deployments on the western Weddell Sea continental shelf during early 2024

1 m binned data of CTD stations in the western Weddell Sea. The filenames have the format SD035_XXX_SS_1m_bin_bestsensor.csv with XXX the cast number. See https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/sd035.pdf for detials of the cast locations. Only the primary conductivity and temperature sensors are included. The oxygen is from the secondary oxygen sensor. Sampling protocol: The SBE911plus CTD was lowered from RRS Sir David Attenborough at an average speed of 1 m s^(-1). The CTD was sampling at 24 Hz. Additional information at https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/sd035.pdf Analytical protocol: The data collected by the Seabird Electronics (SBE) 911plus CTD was calibrated against an SBE35 attached to the CTD frame (for temperature) and Autosal salinometry results from water samples taken throughout the cruise (see https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/sd035.pdf for details). Raw data was processed with SBEDataProcessingSoftware Version 7.26.7. data was converted to csv, low-pass filtering, aligning response times, correcting for thermal mass effects in conductivity, removing pressure loops due to heave and binning the data. Derived variables were calculated in Matlab using the gibbs seawater toolbox (McDougall, T.J. and P.M. Barker, 2011). Parameters used for these processes are: Pressure is low-pass filtered with a time constant of 0.15 s. Conductivity is aligned by shifting by -0.025 s relative to pressure and oxygen is shifted by 3 s relative to pressure. Thermal mass correction parameters are alpha = 0.03 and tau = 7. The minimum velocity for loop editing was set to 0.1 m/s the minimum soak depth was set to 10 m, the maximum soak depth was set to 40 m. Default hysteresis parameters given by SBE were used to correct the oxygen sensor. These are: H1 = -0.033;H2 = 5000;H3 = 1450; The oxygen fit was calculated from bottle values that were manually flagged for good Winkler and bottle values. All bottles where the initial oxygen was more then 10 micro mol/kg different from the Winkler were also removed. This gives R2 values of the fit between uncorrected oxygen and Winkler values of R2 = 0.9987 for the oxygen on the stainless steel rosette The RMSE value of the corrected oxygen (using the fit described above) against the Winkler was RMSE = 1.8 micro mol/kg The fit equations are of the shape oxy_cor = I + a*oxy with the parameters given below I = 2.4824a = 1.0023 Absent data value: NaN Binned data resolution: 1 m Variable names and units: abs_sal -- absolute salinity g/kgchl -- Fluorescence, Chelsea Aqua 3 Chl Con [micro g l-1][milli g m^-3]con -- conductivity [milli S/cm]cons_temp -- conservative temperature [degC]dens -- in situ density [g/kg]lat -- latitudelon -- longitudeoxy -- oxygen concentration [micro mol kg-1]par -- PAR/Irradiance, Biospherical/Licor pdens -- potential density [g/km] pres -- pressure [db]ptemp -- potential temperature [degC]sal -- salinity [PSU]temp -- in situ temperature ITS90 [degC]timedt -- time in human readable format, time zone UTC [dd/mm/yyyy HH:MM:SS]z -- Depth [m] References: McDougall, T.J. and P.M. Barker, 2011: Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox, 28pp., SCOR/IAPSO WG127, ISBN 978-0-646-55621-5