CDOM Absorption Properties of Natural Water Bodies along Extreme Environmental Gradients

• Published in: Water
• Main Authors: Ciren Nima, Øyvind Frette, Børge Hamre, Jakob J. Stamnes, Yi-Chun Chen, Kai Sørensen, Marit Norli, Daren Lu, Qianguo Xing, Dennis Muyimbwa, Taddeo Ssenyonga, Knut H. Stamnes, Svein Rune Erga
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2019
• Subjects: CDOM absorption spectral slope; S R; absorption coefficient; CDOM origin; Hydraulic engineering; TC1-978; Water supply for domestic and industrial purposes; TD201-500; Norway; Røst; Subarctic
• Online Access: https://doi.org/10.3390/w11101988; https://doaj.org/article/d7a31817a8854c669fcc53b241b1da95

We present absorption properties of colored dissolved organic matter (CDOM) sampled in six different water bodies along extreme altitudinal, latitudinal, and trophic state gradients. Three sites are in Norway: the mesotrophic Lysefjord (LF), Samnangerfjord (SF), and Røst Coastal Water (RCW); two sites are in China: the oligotrophic Lake Namtso (LN) and the eutrophic Bohai Sea (BS); and one site is in Uganda: the eutrophic Lake Victoria (LV). The site locations ranged from equatorial to subarctic regions, and they included water types from oligotrophic to eutrophic and altitudes from 0 m to 4700 m. The mean CDOM absorption coefficients at 440 nm [ <math display="inline"> <semantics> <mrow> <msub> <mi>a</mi> <mi>CDOM</mi> </msub> <mrow> <mo>(</mo> <mn>440</mn> <mo>)</mo> </mrow> </mrow> </semantics> </math> ] and 320 nm [ <math display="inline"> <semantics> <mrow> <msub> <mi>a</mi> <mi>CDOM</mi> </msub> <mrow> <mo>(</mo> <mn>320</mn> <mo>)</mo> </mrow> </mrow> </semantics> </math> ] varied in the ranges 0.063−0.35 m <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> </semantics> </math> and 0.34−2.28 m <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> </semantics> </math> , respectively, with highest values in LV, Uganda and the lowest in the high-altitude LN, Tibet. The mean spectral slopes <math display="inline"> <semantics> <msub> <mi>S</mi> <mrow> <mn>280</mn> <mo>−</mo> <mn>500</mn> </mrow> </msub> </semantics> ...