Hoppmann, Mario

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Continuous thermosalinograph oceanographyalong RV POLARSTERN cruise track PS124Data Processing ReportContents1 Introduction 12 Sensor Details 13 Processing Report 24 Appendix 6Contact:Dr. Mario HoppmannAlfred-Wegener-InstituteKlußmannstr. 3d,D-27570 Bremerhaven, GERMANYMail: Mario.Hoppmann@awi.deProcessing Agency:FIELAXGesellschaft für wissenschaftliche Datenverarbeitung mbHSchleusenstr. 14, D-27568 Bremerhaven, GERMANYTel: +49 (0) 471 30015 0Fax: +49 (0) 471 30015 22Mail: info@fielax.deRef.: PS124_TSG.pdf Vers.: 1 Date: 2021/09/29 Status: final11 IntroductionThis report describes the processing of raw data acquired by the thermosalinographs on board RVPolarstern during expedition PS124 to receive cleaned up and corrected salinity data. Detaileddescription of the processing of the data and the workflow is given in the general report “GeneralProcessing Report of Surface T/S Data RV Polarstern Cruises PS123, PS124 and PS125”.Cruise detailsVessel name: RV PolarsternCruise name: PS124Cruise start: 2021-02-04Cruise end: 2021-03-31Cruise duration: 55 daysWorking area: Scotia Sea; South Atlantic Ocean; Weddell Sea2 Sensor DetailsFollowing sensors were installed during cruise PS124. Only data from TSG1 are uploaded to PAN-GAEA for cruise PS124 and are furthermore considered in this report (for reasoning see GeneralProcessing Report).TSG1 TSG2Serial number SBE21-3191 SBE21-3271Installation 2020-12-20 2020-12-20Deinstallation 2021-04-29 2021-04-29Days installed 130 130External temperature sensor SBE38-0118 SBE38-0137Page 1 of 73 Processing ReportDatabase ExtractionData source DSHIP database (dship.awi.de)Start of raw file 2021-02-04T16:00:00End of raw file 2021-03-30T07:59:59Number of lines in hexadecimal rawfile4636800First dataset 2021-02-04T16:00:03Last dataset 2021-03-29T16:55:03TSG1 valid data 1143404Calculation of 10min meansThe calculation of 10min means included the removal of outliers outside a 2-times standard devia-tion for each data interval. The number of outliers for each parameter are given here.Number of outliers >2*stdInternal temperature 41575Conductivity 38341External temperature 41913Salinity 49704Result after outlier removalNumber 10-min-means 7625Manual flaggingAfter processing the data were visually inspected. The whole data from a specific timestamp weredeleted if there was only one parameter to be manually flagged. 18 data points were manually re-moved from the TSG1 dataset of PS124.Assigning navigation dataData from the corrected mastertrack of cruise PS124 were assigned to the 10min means of TSG1.A speed filter of 0.5 knots minimum speed is applied to avoid redundant data. See Figure 1 andFigure 2 for the processed and corrected data of TSG1.Number of speed flags: 2368Number of data in final output file: 5241Page 2 of 7Figure 1: 10min means of data from TSG1Figure 2: Standard deviations of 10min means of data from TSG1Page 3 of 7Differences between internal and external temperature of TSG1 temperature sensorsTemperature differences between the internal and the external temperature sensors have to be smallunder normal circulation conditions. Means and standard deviations for the temperature differencesas well as the number of data with a difference larger than 1 ◦C are given in the following table andare shown in Figure 3.TSG1 temperature differencemean ± standard dev. no. > 1◦CSpot values 0.0584 ± 0.0669◦C 90610-min means 0.0585 ± 0.0639◦C 6Figure 3: Differences between internal and external temperature sensors of TSG1Result fileThe result file is a plain text (tab-delimited values) file named PS124_surf_oce.tab with one datarow in 10-min interval. Salinity values are calculated from the 10min means of conductivity and in-ternal temperature data using a pressure of 11 dbar for the calculations. The pressure refers to the11m water depth of the water inlet of the TSG system on R.V. Polarstern. Water temperature takenfrom the TSG external temperature sensor is given for reference.Page 4 of 7Column separator Tabulator "\t"Column 1 Date and time expressed according to ISO 8601Column 2 Latitude in decimal format, unit degreeColumn 3 Longitude in decimal format, unit degreeColumn 4 Water Temperature, unit degree celsiusColumn 5 TSG Internal Temperature, unit degree celsiusColumn 6 Conductivity, unit mS/cmColumn 7 Salinity, PSUCommentsData gaps due to system maintenance or system shutdown during harbour time:• 17.02.2021; ca. 13:09UTC - 15:29UTC TSG off due to maintenance• 09.03.2021; ca. 08:42UTC - 10:51UTC TSG off due to maintenance• 29.03.2021; ca. 16:00UTC - Dship data aquisition stopped due to entering EEZApart from this, data gaps are caused by speed flagging or manual removal of outliers.Page 5 of 74 AppendixFigure 4: Salinity data from TSG1Page 6 of 7Figure 5: Temperature data from TSG1Page 7 of 7

Continuous thermosalinograph oceanography along RV POLARSTERN cruise track PS124

https://epic.awi.de/id/eprint/54660/1/PS124_TSG_nav.pdf

Continuous thermosalinograph oceanography along RV POLARSTERN cruise track PS124

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