M/V Atlantic Cartier cruise: CAR17-06 Expocode: 77IH20170503 This work was supported by the German component of the Integrated Carbon Observing System (ICOS-D) which received funding by BMBF under grant agreement 01LK1224J. Initial submission: 2018 Most recent update: 11. January 2018 Date of cruise (dd/mm/yyyy): 03.05. - 10.05.2017 Geographic coverage: 52°N, 7°W – 44°N, 63°W Ports of call: Liverpool, UK - Halifax, Canada Vessel name: M/V Atlantic Cartier Vessel ID: SCKB Country: Sweden Owner: Atlantic Container Lines PI: Tobias Steinhoff (GEOMAR/Germany) Arne Körtzinger (GEOMAR/Germany) Douglas Wallace(Dalhousie/Canada) Contact: Tobias Steinhoff GEOMAR Helmholtz Centre for Ocean Research Kiel Duesternbrooker Weg 20 24105 Kiel Germany tsteinhoff@geomar.de Reported variables: (1-3) Year|Month|Day date (4-6) Hour|Minute|Second time (UTC) (7) Day of year decimal year day (8) Longitude [deg E] Longitude in decimal degrees E (9) Latitude [deg N] Latitude in decimal degrees N (10) SST [deg C] Sea surface temperature in deg C (11) SSS Sea surface salinity (12) Atm. Pressure [mbar] Atmospheric pressure in mbar (13) Equi Temp [deg C] Water temperature inside the equilibrator in deg C (14) Equi Press [mbar] Pressureinside the equilibrator in mbar (15) xCO2 (equi temp, dry) [ppm] mole fraction of CO2 in the equilibrator headspace (dry) at equilibrator temperature in ppm (16) pCO2 (SST, 100hum) [uatm] partial pressure of CO2 in seawater at SST and 100% humidity in µatm (17) fCO2 (SST, 100hum) [uatm] fugacity of CO2 in seawater at SST and 100% humidity in µatm (18) Atm. xCO2 (dry) [ppm] mole fraction of CO2 of atmospheric air in ppm (19) Atm xCO2 (dry, running mean) [ppm] same as 18 but with a running mean 800 minutes to interpolate between measurements. Instrument information: - SST (± 0.3 deg C): Themosalinograph data were not recorded. SST was estimated from equilibrator temp and water flow. Please see additional information below. -Equilibrator temp (±0.05 °C): Equilibrator temperature is measured by a Fluke Hart 1521, which is known to be stable over a longer period. It was calibrated in 2014 and regularly checked against the SBE38. -SSS (± 0.5 PSU): Themosalinograph data were not recorded. Data from World Ocean Atlas (Antonov, 2010). -Atmospheric press. (± 0.1 mbar): Atmospheric pressure was measured using a Druck barometer with a precision of 0.2%. The sensor is installed on the bridge deck at approximately 40 m height and pressure is corrected to sea level. -Equilibrator press (± 0.1 mbar): The equilibrator is open to the atmosphere. The pressure outside the equilibrator is measured directly next to the equilibrator by a DRUCK pressure sensor (model no 270). A SETRA difference pressure sensor is attached to the equilibrator. -pCO2/fCO2 (±5µatm): Accuracy of pCO2/fCO2 data was recalculated to be better than 5 µatm due to temperature estimation. IR sensor: Licor 6252, calibrated with 2 standard gases. Standard gases: Deuste Steininger (199.8, 1000.4), calibrated according to WMO standards by the ICOS calibration lab in Jena/Germany. Water flow rate: 2-3 L min-1 Gas flow rate: 140 mL min-1 A so-called Neill system was used for pCO2 measurements. The system is described in detail in Pierrot (2009) and the whole setup is described in Steinhoff (2010). Surface water is pumped continuously (by a torque flow pump) from the intake to the equilibrator. The equilibrator contains a water spray head, and as the water flows through it the dissolved CO2 equilibrates with the headspace. The headspace is dried and xCO2 is determined by an infrared sensor. Calculations were performed following Pierrot (2009) and are described in detail in Steinhoff (2010). References: Pierrot, D., Neill, C., Sullivan, K., Castle, R., Wanninkhof, R., Lüger, H., Johannessen, T., Olsen, A., Feely, R. A., and Cosca, C. E. (2009). Recommendations for autonomous underway pCO2 measuring systems and data reduction routines. Deep-Sea Res. II , 56, 512_522. Steinhoff, T. (2010). Carbon and nutrient fluxes in the North Atlantic Ocean. Dissertation. http://eldiss.uni-kiel.de/macau/receive/dissertation_diss_00005704 Antonov, J. I., D. Seidov, T. P. Boyer, R. A. Locarnini, A. V. Mishonov, H. E. Garcia, O. K. Baranova, M. M. Zweng, and D. R. Johnson (2010). World Ocean Atlas 2009, Volume 2: Salinity. S. Levitus, Ed. NOAA Atlas NESDIS 69, U.S. Government Printing Office, Washington, D.C., 184 pp. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Temperature correction for Cartier cruises in 2017 For the time where no TSG readings were available the intake temperature (Tin) was estimated by a MLR resulting in the following equation: (1) Tin = -4.285 + 1.0154 x Tequ + 0.9487 x Flowh2o where Tequ is the temperature inside the equilibrator in °C and Flowh2o is the recorded water flow in L min-1. The resulting uncertainty was estimated to be 0.3°C. This relationship is valid for temperatures between 1.5°C and 18°C. Justification: 1. During CAR16-06 and CAR16-07 the TSG was working properly. For each cruise the MLR according to eq. 1 was calculated using Matlab: (1) CAR16-06: Tin = -4.982 + 1.0055 x Tequ + 1.2293 x Flowh2o (2) CAR16-07: Tin = -4.434 + 1.0232 x Tequ + 0.9699 x Flowh2o 2. The equation derived from CAR16-06 was used to calculate Tin from CAR16-07 and vice versa. The calculated Tin was compared to the measured Tin Tin (CAR16-06 calculated with eq. 3): mean difference = 0.004°C; standard deviation = 0.25°C Tin (CAR16-07 calculated with eq. 2): mean difference = -0.014°C; standard deviation = 0.31°C 3. For eq. 1 the data of CAR16-06 and CAR16-07 were combined and the MLR was established.