Vibrant vegetation in a Venezuelan lake, Saharan dust in snowy Sierra Nevada, cloud vortices in South Korea, a vast solar farm in China, and a lone ship in the Atlantic are among our satellite images this month
Every so often, a vibrant green colour infuses the waters of Lake Maracaibo. Floating vegetation – likely duckweed – was swirling in the Venezuelan lake when Nasa’s Aqua satellite flew over in February 2017. Most of the time, Maracaibo’s waters are stratified into layers, with nutrient-rich, cooler, saltier water at the bottom, and a warmer, fresher layer near the surface. But after heavy rains, the layers can mix and make the lake an ideal habitat for plant growth. A narrow strait roughly 6km (4 miles) wide and 40 km (25 miles) long connects the lake to the Gulf of Venezuela and the Caribbean Sea. The influx of saltwater through the strait makes Maracaibo an estuarine lake. This mixing causes the water currents responsible for the concentric swirl pattern, according to Lawrence Kiage, a professor of geoscience at Georgia State University.