PANGAEA_995183 Continuous optical chlorophyll-a and turbidity data along RV SONNE cruise SO303 Oelker, Julia; Gaye, Birgit; Waniek, Joanna J Continuous optical chlorophyll-a and turbidity data along RV SONNE cruise SO303 2026-06-19 PANGAEA Dataset https://doi.pangaea.de/10.1594/PANGAEA.995183 Investigator Julia Oelker julia.oelker@uni-oldenburg.de Earth Science DATE/TIME LATITUDE LONGITUDE DEPTH, water Ship speed Chlorophyll a Quality flag, chlorophyll a Turbidity (Nephelometric turbidity unit) Quality flag, turbidity Measurement container geoscientificInformation chlorophyll-a DAM Fluorescence Fluorometer, Sea-Bird Scientific, ECO FLNTU SO303 SO303_0_Underway-7 turbidity Underway measurement Fluorometer, Sea-Bird Scientific, ECO FLNTU Data quality control procedures according to Copernicus Marine in situ TAC BGC quality control group (2021) Fluorometer, Sea-Bird Scientific, ECO FLNTU; Calibration according to Data processing report Fluorometer, Sea-Bird Scientific, ECO FLNTU; Sensor alignment correction according to Data Processing Report Sonne_2 2024-01-10 2024-02-19 Complete -23.20423 7.08016 51.67094 80.11346 4.0 m (DEPTH, water) 4.0 m (DEPTH, water) DAM_Underway DAM Underway Research Data DataHub DataHub Earth and Environment of the Helmholtz Association unrestricted CC-BY-4.0: Creative Commons Attribution 4.0 International English PANGAEA Data Publisher for Earth & Environmental Science https://www.pangaea.de/ Data Center Contact Michael Diepenbroek info@pangaea.de

Leobener Str.

Bremen Bremen 28359 Germany online 452461 data points text/tab-separated-values Gaye, Birgit; Andersch, Tjark; Bartsch, Peggy; Cosmus, Hannes; Dähnke, Kirstin; Dasbach, Dorothee; Eisnecker, Paula; Gök, Irmak; Harms, Natalie; Hubert-Huard, Raphaël; Hüge, Fabian; John, Finn; Keuter, Sabine; Kretzschmann, Lisett; Lahajnar, Niko; Lisitano, Luisa; Lüdmann, Thomas; Markfort, Greta; Meiritz, Luisa Chiara; Oldhaver, Manja; Penopp, Jan; Prien, Ralf D; Rixen, Tim; Ruda, Luise; Sanders, Tina; Schulz, Gesa; Schulz, Hartmut; Siccha, Michael; Sommer, Marcel; Sorge, Yves; Waniek, Joanna J (2024): BIOGeochemistry in the equatorial INdian Ocean - BIOGIN-IIOE2, Cruise No. SO303, 23.01.2024 - 19.02.2024, La Réunion (France) - Colombo (Sri Lanka). SONNE-Berichte, Begutachtungspanel Forschungsschiffe, SO303, 81 pp, https://doi.org/10.48433/cr_so303 Oelker, Julia (2026): Continuous optical chlorophyll-a and turbidity data along R/V SONNE cruise SO303 - Data Processing Report. Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, https://download.pangaea.de/reference/140048/attachments/DAM_DataProcessingReport_SO303.pdf Guidelines for measuring chlorophyll a (2017). Baltic Marine Environment Protection Commission - Helsinki Commission (HELCOM), https://helcom.fi/publications/guidelines-for-measuring-chlorophyll-a/

Underway optical chlorophyll-a and turbidity data were collected along the cruise track with Sea-Bird Scientific ECO FLNTU sensors installed within two autonomous measurement systems, called self-cleaning monitoring boxes (SMBs). The SMBs measure alternatingly. While one box is measuring, the other one is being cleaned. The boxes switched generally every 6 hours. The water inlet for the SMBs is at about 4 m below sea surface. Observed chlorophyll-a and turbidity data were both quality controlled. Analysis of the chlorophyll-a and turbidity data during parallel operation of the sensors in the two boxes showed significant differences between the sensors. The sensors were aligned resulting in consistent chlorophyll-a and turbidity time series. The corrected chlorophyll-a data were calibrated based on chlorophyll-a values from discrete water samples taken from the underway system and measured fluorometrically in the lab. The turbidity time series was compared against suspended particulate matter (SPM) from surface water samples taken from Niskin bottles of the CTD frame and determined gravimetrically in the lab. Correlation between turbidity and sample SPM was poor. The calibrated chlorophyll-a time series and corrected turbidity time series were compared against Globcolour CHL1 and TSM products, respectively. Details on all quality control steps and the comparison with satellite data can be found in the data processing report. The data set user should keep in mind that some parts of the time series might be affected by non-photochemical quenching, see data processing report. It was out of the scope of the quality control to flag or correct non-photochemical quenching. The resulting data set contains the original data and corresponding quality flags achieved by the quality control algorithm as well as the calibrated chlorophyll-a and corrected turbidity data with corresponding quality flags. The data source is given through the name of the active SMB. The data set contains data during transit time and station work. We recommend to use ship's speed to filter for only transit data. ** For all details see the full metadata description at "https://doi.pangaea.de/10.1594/PANGAEA.995183"!

http://en.wikipedia.org/wiki/ISO_6709 LATITUDE http://en.wikipedia.org/wiki/ISO_6709 LONGITUDE http://en.wikipedia.org/wiki/ISO_8601 DATE/TIME https://archimer.ifremer.fr/doc/00251/36232/ Data quality control procedures according to Copernicus Marine in situ TAC BGC quality control group (2021) https://doi.org/10.48433/cr_so303 BIOGeochemistry in the equatorial INdian Ocean - BIOGIN-IIOE2, Cruise No. SO303, 23.01.2024 - 19.02.2024, La Réunion (France) - Colombo (Sri Lanka) https://en.wikipedia.org/wiki/Turbidity Turbidity (Nephelometric turbidity unit) https://hdl.handle.net/10013/epic.32187.d001 Chlorophyll a https://helcom.fi/publications/guidelines-for-measuring-chlorophyll-a/ Guidelines for measuring chlorophyll a https://helmholtz.software/projects/datahub DataHub https://uol.de/icbm/forschungsplattformen-schiffe/sonne Sonne_2 https://www.allianz-meeresforschung.de/kernbereiche/datenmanagement-und-digitalisierung#unterwegs DAM_Underway DIF 9.4 2026-06-19 2026-06-19