Baltic Sea - Gulf of Riga - DIVAnd 4D seasonal analysis of Water body chlorophyll-a 2001/2021 v2023

Water body chlorophyll-a - Seasonal Climatology for Gulf of Riga for the period 2001-2021. Four seasons (March-May, June-August, September-November, December-February). Analyses for depths (m) (HELCOM standard depths): 0, 5, 10, 15, 20, 25, 30, 40. Data Sources: observational data from SeaDataNet/EMODnet Chemistry Data Network. Description of DIVAnd analysis: Geostatistical data analysis by DIVA (Data-Interpolating Variational Analysis) tool. GEBCO_04 Grid (30 arc-seconds) topography is used for the contouring preparation. Files contain analysed fields, error fields and combined field with the deepest value for each grid point selected. Also pre-masked fields using relative error threshold 0.3 and 0.5 are included. In the analyses the horizontal correlation length is fixed to 25 km and decreasing towards the coastline, the vertical correlation length is varying with depth. Signal to noise ratio were fixed to 1.0. Log transformation was used in the analyses. No detrending, advection constraints or weighting are applied. The horizontal resolution of the produced DIVAnd maps grids is 0.01 degrees. Unit is mg/m3.