Eye of an Algal Storm

New images of an impressive massive algal bloom in the Baltic Sea, captured by the Sentinel-2A satellite that has been in orbit for only some weeks. Can you see the boat?

Above: Sentinel-2A captured this detailed image of an algal bloom in the middle of the Baltic Sea on 7 August 2015. The image, which has a spatial resolution of 10 m, reveals the bloom in exquisite detail as well as a ship heading into the ‘eye of this algal storm’. The ship’s wake can be seen (on top center) as a straight dark line where the bloom has been disturbed by the ship’s propellers.   Credit: Copernicus Sentinel data (2015)/ESA

Built essentially as a land monitoring mission, Sentinel-2 will also certainly find its way into marine applications.

Warm weather and calm seas this August have increased the amount of biological activity in the central Baltic Sea, with the Finnish algae monitoring service [email protected] reporting a dominance of cyanobacteria in the region at this time.

Algal bloom in the Baltic Sea

This red–blue–green composite image shows an algal bloom in the central Baltic Sea.   Credit: Copernicus Sentinel data (2015)/ESA

The Baltic Sea faces many serious challenges, including toxic pollutants, deep-water oxygen deficiencies, and toxic blooms of cyanobacteria affecting the ecosystem, aquaculture and tourism.

The situation was so bad that in 1974 the Helsinki Convention for the Protection of the Marine Environment of the Baltic Sea Area was created to improve the state of the sea. Since then, the health of the Baltic Sea has improved dramatically.

Algal bloom in the Baltic Sea 2

This image of an algal bloom in the central Baltic Sea was captured by Sentinel-2A on 7 August 2015. The Estonian island of Saaremaa, which is home to the Kura kurgu hoiuala conservation area, is visible in the upper right of the image.   Credit Copernicus Sentinel data (2015)/ESA

source ESA