The visualization of Seili-index describes the present chlorophyll-α concentration (chl-a; µg/l) in surface seawater and predicts its changes 10 days ahead. The index values represent the total amount of phytoplankton at fixed monitoring station in the vicinity of Seili Island and reflect the level of eutrophication of the sea in general.
In the visualization, a larger sphere and a greener color indicate higher level of eutrophication and turbid seawater, and a smaller and bluer sphere for cleaner seawater. Thus, changes in index values may indicate, for example, the onset of phytoplankton blooms as well as an increasing/decreasing state of seawater quality in general.
The prediction is based on the Generalized Additive Mixed Models (GAMM), which manifests the relationship between chlorophyll-α content and surface water/ surface air temperatures. The chlorophyll content data is based on data derived from the Seili automatic profiling monitoring buoy and temperature data from a 10-day long-term forecast from the Norwegian Meteorological Institute. The GAMM model of the index has been created by PhD Joni Virta University of Turku / Aalto University and the visualization by Tommy Löwendahl and the IT of the University of Turku.
Open data licence: The data at https://saaristomeri.utu.fi website is licenced with The Creative Commons Attribution 4.0 International license (CC BY 4.0). How to cite: “Seili Environmental monitoring programme, Seili-index portal. YEAR. Turku University/ Turku University of Applied sciences, Turku. https://saaristomeri.utu.fi/seili-index/”.
The automatic profiling monitoring buoy has been stored away for winter. The Seili-index will update again in spring 2021 after the buoy is launched back to the sea.