Biogeochemical trends from S3-OLCI

Statistical trends of Chlorophyll-a and Total Suspended Matter concentrations at the sea surface. Statistical trends of TSM and Chl are calculated over the 2017-2024 S3-OLCI time series by deseasonalizing the time series via the X-11 procedure, which decomposes the original time series (of both TSM and Chl) into three different components: the seasonal signal, the trend component, and an irregular component (Shiskin, 1978; Dagum, 1980). Then, the Mann-Kendal (MK) test and the Sens’s method (Mann, 1945; Kendall, 1948; Sen, 1968) will be applied to the deseasonalized time series of TSM and Chl to estimate the statistical trends (Colella et al., 2016).