CTD Underway Data

On this page you will find information on the requirements for submitting, archiving and publishing Conductivity, Temperature, Depth Sonde (CTD) Underway Data, as well as examples of datasets. Although not "underway" per definition, CTD data taken continuously onboard a research vessel without scientific program will be named "underway" here for the sake of consistency with similar efforts with other devices.

General information about CTD data, which is not necessarily related to the DAM Underway Research Data Project, can be found here.

Underway Data from different devices
During DAM pilot phase, workflows for data curation, archiving and publication at PANGAEA are being revised. Besides CTD, other types of processed Underway Data from different devices are in the scope of the project:
 * ADCP Underway Data
 * Ferrybox Underway Data
 * Bio-optical Sensors Underway Data
 * TSG Underway Data

Furthermore, historical and recent Bathymetry data and corresponding workflows are under revision in the framework of DAM.

Examples of a CTD Underway Data Publication
Physical oceanography during RV HEINCKE cruise HE609: https://doi.pangaea.de/10.1594/PANGAEA.961721.

Physical oceanography during RV MARIA S. MERIAN cruise MSM105: https://doi.pangaea.de/10.1594/PANGAEA.956306 (dataset in review)

Standardized Meta-Information of Underway Data
The following information needs to be included in any Underway Data submission at PANGAEA. To start a data submission at PANGAEA go to https://www.pangaea.de/submit/. Further information on the ticket system used for communication and documentation during the processing of the data submission can be found in this wiki.

List of Authors
Usually, the list of authors of Underway Data contain the scientist responsible for the sampling device and the chief scientist.

Dataset Title
The title of the data publication should be generalized and is defined by the specific [ship], [cruise] and [device] (see ).

Abstract
For Underway Data a generalized Abstract per device may be created that will be adapted to each dataset regarding [ship], [cruise] and certain peculiarities. For more information on what needs to be included in a PANGAEA data publication abstract see this page.

Cruise Report
The Cruise Report is usually already archived at the Technische Informationsbibliothek and will be linked to the dataset by a data curator (see this example).

Data Processing Report
The Data Processing Report contains information on processing and quality control procedures. It enables to reproduce the processed data from raw data. The preferred format for submission is pdf. Example: Schlundt, Michael; Wölfl, Anne-Cathrin (2020): Continuous thermosalinograph oceanography along Maria S. Merian cruise MSM 88/2 - Data Processing Report. GEOMAR - Helmholtz Centre for Ocean Research Kiel, https://store.pangaea.de/Publications/Woelfl-Schlundt_2020/DAM_DataProcessingReport_MSM88_2.pdf

Currently, the Data Processing Reports are being archived at PANGAEA (except for reports for data obtained during Polarstern and Heincke cruises); A long-term solution will include the assignment of a doi for each Data Processing Report.

Raw Data
If possible, the raw data should be linked to the processed dataset. This link may lead to an external source, but it may also be an PANGAEA-internal link. A detailed description on CTD raw data can be found here.

Cruise Label
The [Cruise] Label given should always include [ship]number/leg (e.g.: MSM88/1).

Event label(s)
The Event Label(s) should be part of each data submission. Event labels equal the station labels and provide meta-information for the data. The Underway Event Label is being created onboard and should always be used when referring to Underway Data (current exception: CTD Data - several events needed). The format of Event Labels format consists of the cruise label and the station ending: [ship]number/leg_station (e.g.: HE549_10-1).

Device/Sensor
Information on the device used for measuring should also be provided, so it can be linked to the measured parameters.

Keywords/Project
Use "DAM:Underway Research Project" as project and technical keyword "DAMUnderwayResearch".

File name
A generalized file name should be used per device (see )

File Formats
Possible file formats include .txt, .tab, .csv, .xlsx. The encoding is preferably UTF-8.

Layout
Please do not include any header except column names. The decimal separator should be "." and the number of decimals should always reflect the measurement precision. Not available numbers are displayed as blanks in PANGAEA. They should be included as blanks, "NaN", or "NA" in the data table.

Parameters of the data table
This table gives an overview on the parameter names and specifications as they will appear on the web and in the download file of the data. If possible, these names should be included in the submission data table. Also the format and unit of data should be submitted as displayed here. The methods will be included in the data publication by the data editor as specified in the submitted meta-information.

Note: If Quality Flags are used, the flagging code needs to be explained and will be archived in the parameter comment.

Templates for processed CTD data submissions[edit | edit source]
These templates may help for preparation of your data file:


 * template in tab delimited text format (preferred); Additional meta information as name of the principal investigator and name of method and device are given as comments during the submission process.


 * template in excel format; Additional meta information as name of the principal investigator and name of method and device are either given as comments during the submission process or via an additional sheet in the excel file.

A few information on density in water:

Density = 1027.1234

Sigma = Density - 1000 = 27.1234

Density depends on pressure, temperature and salt content: Density = f(P,T,S)

As a rule, one considers the density (or sigma) and sets P = 0 and denotes this as sigma-theta.

If the potential temperature (theta) is used instead of the in-situ temperature T, then the result is the potential density or sigma-theta.

Density in situ ( Note: "Density, mass density [kg/m³]" in 4D) - should always have values around 1000 (e.g. 1027)

Density, potential [kg/m³] should also always have values around 1000 (e.g. 1027)

Density sigma-theta [kg/m³] should always have lower tens values, e.g. around 27

Density, sigma, in situ [kg/m³] should also have lower tens values, e.g. around 27