Photo: NASA Earth Observatory
This photo was captured by the Moderate Resolution Imaging Spectroradiometer on NASA’s Aqua satellite from the International Space Station. It highlights a late-summer “whiting event” visible across Lake Ontario. Whiting events are caused by changes in the water’s temperature, which leads to increased photosynthesis by phytoplankton and other microscopic marine life. That photosynthesis reduces the amount of carbon dioxide in the water, which changes the water’s acidity. Change in acidity and temperature then allows fine particles of calcium carbonate to form in the water column, and it’s these particles that cause the characteristic lightening, or “whiting,” of the water’s color.
This photo was captured on August 24, 2013, by the Expedition 36 crew, and can also be seen on NASA’s website.