Algal bloom around Falkland Islands
Falkland Islands | South Atlantic Ocean
Date of acquisition: December 28th, 2024 | 12:54:46 UTC
Sensor: Sentinel-3 OLCI
Coordinates: ca. 52°S, 60°W
As every year, the algal bloom in the southwest Atlantic has been going on for several weeks. Unfortunately, the sky was too cloudy, and the bloom could only be observed in fragments.
It was not until the end of December that the weather cleared, and the phytoplankton bloom became visible in all its glory.
The Sentinel-3 OLCI image (Figure 1) shows a huge algal bloom forming a ring around the Falkland Islands (Islas Malvinas). This ring is about 1500 km long and on average about 50 km wide.
We see various shades of green and blue, due to the presence of different phytoplankton communities. The chlorophyll-rich diatoms colour the water green, while the coccolithophores, which form calcium carbonate plates on their surface, appear milky turquoise.
Algorithms for identifying different phytoplankton groups from image data are improving and provide valuable results also thanks to the availability of hyperspectral (high-resolution wavelength) data.
Figure 2 shows how the situation has changed by 19 January 2025.
