Aggregations

Aggregations

In the Tarkka service, the following composite datasets area available to support both water quality and land cover monitoring:

Aggregations	Years	More info
Summer observations of turbidity (seasonal aggregates)	2015–2018	Compilation of cloudless S2 observations (60 m) of turbidity observations from open seas, coastal areas, and lakes for water quality assessment. The annual period covered by the composite is from June 1st to September 30th for open sea and lake areas, and from July 1st to September 7th for coastal water formations.
Surface algae blooms aggregations	2003–>	Aggregated from the surface algae blooms between July and August. Instrument has changed during the observation periods: 2003-2011 MERIS, 2012-2016 MODIS, 2016→ OLCI ja MSI.
River catchment areas	2003-2011	From the ENVISAT/MERIS observations, mostly based upon turbidity observations from springtime which are divided to four classes and resuspension has been removed
Geometric mean of chlorophyll-a	2003-2011, 2016-2018	Aggregation of cloudless chlorophyll-a observations on the Baltic sea between the 1st of June to the 30th of August. The instrument used is different for different time periods: 2003-2011 MERIS, 2016→ OLCI.
Landcover indexes (NDVI, NDTI, NDSI, NDMI, NDBI)	2017-	Composites produced from cloudless Sentinel 2 observations.