Please note that operations of the CTD (Conductivity-Temperature-Depth) watersampler requires experienced scientific staff on board. The system is not operated by the ship's crew. Announce operations with the CTD watersampler to AWI-Logistics prior to the cruise and clarify the data transfer after the cruise.

Summary

The CTD probe measures conductivity and temperature along a vertical transect through the water body. The measured parameter are used to calculate the salinity of the water. Additionally, up to 24 water samples can be taken in different water depths during the CTD measurements. A fluorometer, an oxygen sensor and a transmissiometer are attached to the CTD as well. The system is operational up to 2000m water depth.



ManufacturerSeabird
ModelSBE911plus mit SBE32
Serial No.n/a
TypeCTD





Contacts

NameInstitutionRole
Gerd RohardtAlfred-Wegener-InstituteData Scientist
Andreas WisotzkyAlfred-Wegener-Institute for Polar and Marine ResearchData Scientist

Components

The CTD system consists of the underwater unit SBE 9plus, the deck unit SBE 11plus V2 and the carousel water sampler SBE32 which is equipped with free flow water samplers manufactured by Hydro-Bios. The CTD is outfitted with a double set of temperature (SBE 3plus) and conductivity (SBE 4C) sensors that are calibrated regularly. Additionally, an altimeter, a transmissometer, an oxygen sensor and a fluorometer may be attached to the CTD unit and operated to water depths of 6000m.

On the CTD data aquisition PC in the Messraum following software is installed: aquisition software Seasave (Version V7_19), SBE Data processing software, ManageCTD software packet for cleansing and conversion of the data and Ocean Data View (ODV) for visualization.


NameModelType
PSA-916 Sonar AltimeterPSA-916altimeter
SBE32 water samplerSBE32remote water sampler
SBE3plus temperature sensorSBE3plustemperature sensor
SBE4 conductivity sensorSBE4conductivity meter
SBE43 oxygene sensorSBE43oxygen sensor
C-Star transmissometerC-Startransmissometer
ECO FL fluorometerECO FLfluorescence Sensor
SBE 5P pumpSBE 5Ppump

Position


Origin Description:The CTD unit is usually stored on the main deck. Electronics and the computer for operation are installed in the Mess- und Registrierraum.

Data logging, storage and archiving

Logged parameters

ParameterSensor Output TypeUnit
conductivityconductivityS/m
water temperaturewater temperature°C
oxygen contentoxygenml/l
pressurepressuredbar
fluorescencefluorescenceV
distance to sea floordistancem
transmissiontransmission%

Central geographical ship's position and time standard

The PC is time synchronised  via the Windows-Domain-Affiliation. Geographic position and UTC time is made available to the system via NMEA telegram and read by Seasave software.

Rawdata storage on board

Raw data are stored with the ManageCTD software on the aquisiton PC in following data structure:
|| root directory | \\xdc\scientists\data\CTD\ ||
|| directory name | CruiseNo e.g. HE507 with subdirectories ||
|| Data volume (MB per day) ca | 50 || 
|| Number of files per day ca | 10 ||

Data archiving on land

After consultation with the data scientist and AWI Logistics the CTD data including meta data may be transferred to PANGAEA  (https://www.pangaea.de/)

Documentation