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Reference measurements of surface waters and optical water quality variables (Secchi depth and Forel-Ule color indexes) collected during two RV Otzum cruises along the river Elbe in 2012 and 2013

Description: Reference measurements of surface waters were collected during two RV Otzum cruises along the river Elbe in 2012 and 2013 (Ot2012_05: 21.-24.05., 30.-31.05.2012; Ot2013_05: 23.05., 27.-30.05.2013). Temperature [°C], salinity, turbidity [NTU], and chlorophyll from fluorescence [µg/L] were measured by a PocketFerrybox System (values given to the time of sampling). Water samples were taken from the outlet of the system. Suspended particular matter (SPM) and chlorophyll a (Chl a) were filtered onboard on glas fibre filters (GFF, 47mm, 0,7 µm) and frozen at -25°C and -80°C immediately after sampling. Values were determined in the lab after the cruise within 2 months, for SPM via gravimetric analysis (IOCC recommendations) and for Chl a according to EPA Method 445. Water clarity and color were observed using a white Secchi disc with a diameter of 30 cm and a Forel-Ule color scale. The Secchi depth (SD) was recorded as a relative measure of water clarity at each in situ station during day time. At half SD the apparent color of the water above the submerged Secchi disc was determined using the Forel-Ule color scale. A Forel-Ule color scale is a classic tool used to differentiate the percieved color of water based on a scale from 1 (indigo blue) to 21 (cola brown). The measurements were conducted as recommended in literature (Garaba and Zielinski, 2015; Wernand, 2011; Wernand and van der Woerd, 2010). Measurements were part of the project DOMsense (01.11.2011 - 31.05.2014, KF2866501DF1)

Global identifier: 

Doi(
    "10.1594/PANGAEA.985197",
)

Types: 
DataMeasurements(
    DataMeasurements {
        domain: Unspecified,
        station: None,
        measured_variables: [
            "Event label",
            "DATE/TIME",
            "LATITUDE",
            "LONGITUDE",
            "Station label",
            "Salinity",
            "Temperature, water",
            "Chlorophyll a",
            "Turbidity (Nephelometric turbidity unit)",
            "Chlorophyll a",
            "Suspended particulate matter",
            "Depth of Secchi Disk",
            "Forel-Ule index",
        ],
        methods: [
            "PocketFerryBox, 4H Jena Engineering, [SN: 751502]; measured with Thermosalinograph, Sea-Bird Scientific, SBE45",
            "PocketFerryBox, 4H Jena Engineering, [SN: 751502]; measured with Digital oceanographic thermometer, Sea-Bird Scientific, SBE38",
            "PocketFerryBox, 4H Jena Engineering, [SN: 751502]; measured with Fluorometer, Turner Designs, Cyclops-7",
            "PocketFerryBox, 4H Jena Engineering, [SN: 751502]; measured with Fluorometer, Turner Designs, Cyclops-7",
            "Fluorometer, Turner Designs, Trilogy 7200-002 [EPA Method 445.0]",
            "Gravimetric analysis according to IOCCG (2021)",
            "Secchi disk",
            "Forel-Ule scale",
        ],
    },
)

Origins: /Wissenschaft/PANGAEA

Tags: Fluoreszenz ? Fluss ? Wassertemperatur ? Elbe ? Geografische Koordinaten ? Filter ? Salzgehalt ? Gewässergrund ? Oberflächengewässer ? Wasserqualität ? Wasserprobe ? Wasser ? Trübung ? Chlorophyll a ? Forel-Ule Index ? Optical water quality ? SPM ? Secchi depth ?

Region: Elbe River

Bounding boxes: 8.2223° .. 10.3207° x 53.398° .. 53.9879°

License: cc-by/4.0

Data access requires registration: click here for further information

Language: Englisch/English

Organisations

Persons

Modified: 2025-09-17

Time ranges: 2012-05-22 - 2013-05-29

Resources

Status

Quality score

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