This paper deals with the phenomenon of darker (browner) coastal waters, and is based on long time series of optical properties in the Norwegian coastal waters. The paper shows how browner water from the Baltic Sea, likely related to increased forest volume in the Baltic catchment, change optical properties even up towards Arctic waters.
Paper can be read from the journal website.
Opdal, A.F., Andersen, T., Hessen, D.O., Lindemann, C., Aksnes, D.L., 2023. Tracking freshwater browning and coastal water darkening from boreal forests to the Arctic Ocean. Limnol Oceanogr Letters lol2.10320. https://doi.org/10.1002/lol2.10320