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Data product Baltic Thalweg (Level 4)

(Version 0.3, 22.09.2017, V. Mohrholz)


The data set consists of CTD data of pressure, in-situ temperature, conservative temperature, absolute salinity and dissolved oxygen concentration along the Baltic thalweg transect. It starts in the Kiel Bight at 54°39.6’N, 10°45.6’E and follows the Baltic valley line to 58°58.4’N, 20°12.9’E in the northern Gotland Basin. The total length of the transect is 552 nautical miles (1022km). The data set is derived from validated in-situ measurements with a SeaBird CTD 911 system. The field data were gathered in frame of the IOW long term observation program in the central Baltic and the Baltic monitoring program (western Baltic), funded by the BSH. The field data were interpolated on an equidistant depth vector with 1m depth steps. The parameters conservative temperature and absolute salinity were calculated using the TEOS10 toolbox. The data set covers the ten year period from 2014 to 2019 with 5 grids per year, usually for February, March, May, July and November.

Available time range: November 2014 - August 2019


Structure of NetCDF file:

Global Attributes

 Name  Content
 title  Hydrographic data set of Baltic thalweg transect (CTD data at stations)  
 version  Version number of data product, date of data processing
 subtitle  Cruise description string (e.g. used for figure captions)
 datasetID  Internal cruise identifier (e.g. ‘btw2016_03’)
 cruiseID  Offical cruise number, (e.g. ‘EMB124’)
 reference  Data reference for citation of data product
 publisher  Leibniz Institute for Baltic Sea Research (IOW)
 rights  Level 3 data, only for internal use
 creator  Name of operator
 contact  Email address for information and support
 description     Data set description text



 Name  Axis  Long name  Unit  Description
 depth  Z  Depth  m  Depth below surface, positive downward
 time  T  Time  days  Time of CTD station
 cruise  C  Cruise ID  none  Cruise identifier (e.g. '201603')



Name Axis Long name Unit Description
latitude T-C Latitude deg N Latitude of CTD profile
longitude T-C Longitude deg E Longitude of CTD profile
stat_dist T-C Station distance km Distance along the thalweg transect allocated to CTD station
bottom T-C Bottom depth m Bottom depth from echo sounder
Press T-C Pressure dBar Pressure value data
Temp T-Z-C in-situ Temperature °C in-sito Temperature data
CTemp T-Z-C Conservative temperature °C Conservative temperature data
ASal T-Z-C Absolute salinity g/kg Absolute salinity data
Oxy T-Z-C Dissolved Oxygen μmol/kg Dissolved Oxygen data
stat T-C Station none Station ID of particular cruise
stat_dmin T-C Data profile start depth m Data profile start depth of CTD station (positive down)
stat_dmax T-C Data profile end depth m Data profile end depth of CTD station (positive down)



Creator: Mohrholz, Volker
Titel: Gridded hydrographic data set of Baltic thalweg transect 2014-2019
Publisher: Leibniz Institute for Baltic Sea Research (IOW)
PublicationYear: 2016
Updated 2019
Rights: CC BY-NC-ND 4.0 International


Graphics of the Baltic Thalweg data

2014 2015 2016 2017
2018 2019    
Example for Aug, 2019
Example for Aug, 2019