Sunglint on Atlantic Ocean – NASA

Sunlight beams onto a partly cloudy Atlantic Ocean just after sunrise as the International Space Station orbits 263 miles above on March 5, 2025. This is an example of solar radiation, an optical phenomenon that occurs when sunlight reflects off the water surface at the same angle as a satellite sensor sees it. The result is a mirror-like specular reflection of sunlight on the water and reflected back to the satellite sensor or astronaut.

Although solar flare often produces visually stunning images, this phenomenon can create problems for remote sensing scientists because it obscures features that are usually visible. This is especially true for oceanographers who use satellites to study phytoplankton and ocean color. As a result, researchers have developed several methods to filter solar-contaminated images from data archives.

Despite the challenges posed by sunlight, the phenomenon offers unique scientific opportunities. This makes it easier, for example, to detect oil on the water surface, whether it comes from natural oil seeps or man-made oil spills. In fact, a layer of oil smoothes the surface of the water.

Text credit: Adam Voiland

Image credit: NASA