File:Bloom off South America (MODIS).jpg

English: A massive spring bloom of phytoplankton colored the waters off of Patagonia in early November 2022. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite captured a true-color image of the region on November 3. The jewel-toned hues swirl through the entire ocean visible in this image, with green swirls dominant near-shore and milky blue tones predominate further out in the ocean.

Phytoplankton are microscopic plant-like organisms that float near the surface of the ocean in this area year-round. When conditions are right—warming temperatures, correct sunlight, and abundant nutrients—phytoplankton can reproduce explosively, creating massive and colorful blooms that can be easily seen from space. Different species of phytoplankton contain varying types of pigment and the blooms may appear different from space. For example, milky-blue tones indicate an abundance of coccolithophores, which surround themselves with chalky-colored calcite plates.

Phytoplankton blooms frequently occur off the Patagonian coast for a reason: it is the convergence zone between the warm, southbound Brazil Current near the coast and the cold, northbound Malvinas/Falkland Current farther out to sea. As the currents brush past each other, turbulent swirls and eddies form, causing cold, nutrient-rich water to well up toward the surface from deeper in the ocean. These rich waters provide a buffet to eager, growing phytoplankton. These blooms most often occur in the Southern Hemisphere springtime.