November 30, 2022 - Bloom in the Caspian Sea


Swirls of tan and green filled the southeastern corner of the Caspian Sea on November 29, 2022, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired this true-color image.

The color most likely comes primarily from phytoplankton, which are microscopic plant-like organisms that live in these waters year-round in small numbers. Given adequate sunlight and nutrition, phytoplankton populations can explode into blooms large enough to be easily seen from space. Tan color, especially near the eastern coastline off of Iran’s deserts, is suggestive of floating sediment. Strong winds over the previous few days likely blew sand and dust into this corner of the Caspian Sea.

Phytoplankton blooms are often harmless, and are an important food source for marine life. Other times, blooms can be harmful; they can deplete the water’s oxygen and suffocate marine life, and produce toxins that can be harmful to both aquatic creatures and humans.

Image Facts
Satellite: Aqua
Date Acquired: 11/29/2022
Resolutions: 1km (114 KB), 500m (297.8 KB), 250m (187 KB)
Bands Used: 1,4,3
Image Credit: MODIS Land Rapid Response Team, NASA GSFC