Physical oceanography during POLARSTERN cruise PS117 measured with Ultra-Clean-CTD

Two CTD/water sampler systems were deployed during RV POLARSTERN cruise PS117. Both CTDs are SBE911plus from the manufacturer Seabird Scientific. The data from the AWI CTD have already been processed and are stored in Pangaea under https://doi.pangaea.de/10.1594/PANGAEA.910663 and can be downloaded there. The NIOZ-Ultra Clean CTD incl. water sampler could not be used with direct data transmission, so it was operated together with a SBE17 for control and storage of the data. At the beginning of the cruise there were problems with the setup of the SBE17 unit so that profiles were not recorded completely. After several attempts, the problem was identified in the SBE17. A replacement of this unit was shipped to Neumayer Station and brought on board POLARSTERN. After the replacement of the SBE17 the system worked reliable. However, this also meant that the failure of a conductivity sensor was only detected and replaced at a late stage. For this reason, usable CTD profiles are only available from station 36 onwards. In order to obtain a data set comparable to the AWI-CTD, profiles made with AWI-CTD and NIOZ-CTD at the same stations were used. The difference between the processed AWI-CTD and the unprocessed NIOZ-CTD is used to correct the NIOZ-CTD.