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Titel |
Comparison of UV–VIS and FDOM sensors for in situ monitoring of stream DOC concentrations |
VerfasserIn |
E.-J. Lee, G.-Y. Yoo, Y. Jeong, K.-U. Kim, J.-H. Park, N.-H. Oh |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 12, no. 10 ; Nr. 12, no. 10 (2015-05-28), S.3109-3118 |
Datensatznummer |
250117951
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Publikation (Nr.) |
copernicus.org/bg-12-3109-2015.pdf |
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Zusammenfassung |
Optical measurements using ultraviolet–visible (UV–VIS)
spectrophotometric sensors and fluorescent dissolved organic matter (FDOM)
sensors have recently been used as proxies of dissolved organic carbon (DOC)
concentrations in streams and rivers at a high temporal resolution. Despite the merits of the sensors, temperature changes and particulate matter in
water can interfere with the sensor readings, over- or underestimating DOC
concentrations. However, little efforts have been made to compare responses
of the two types of the sensors to critical interferences such as temperature
and turbidity. The performance of a UV–VIS sensor and an FDOM sensor
was compared in both laboratory experiments and in situ monitoring in a forest stream in Korea during
three storm events. Although the UV–VIS
sensor did not require temperature correction in laboratory experiments
using the forest stream water, the deviations of its values from the DOC concentrations
measured with a TOC analyzer increased linearly as turbidity increased. In
contrast, the FDOM sensor outputs decreased significantly as temperature or
turbidity increased, requiring temperature and turbidity correction for in
situ monitoring of DOC concentrations. The results suggest that temperature
correction is relatively straightforward but turbidity correction may
not be simple because the attenuation of light by particles can significantly
reduce the sensitivity of the sensors in highly turbid waters. Shifts in
composition of fluorophores also need to be carefully tracked using
periodically collected samples since light absorbance and fluorescence can
vary as the concentrations of dominant fluorophores change. |
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