Based on its northerly location—above the Arctic Circle and just 1,300 kilometers (800 miles) from the North Pole—the remote Norwegian archipelago of Svalbard seems like it should be a barren land of snow, ice, and rock. However, the West Spitsbergen Current brings a relatively warm stream of water from the south into the fjords and inlets of western Svalbard. This warm water moderates the climate enough that coastal areas and certain valleys witness an explosion of green in the summer. In contrast, a cool ocean current moving south keeps the eastern coasts of Svalbard’s islands cold and snowy even during the summer.

This image, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite, shows the archipelago as it appeared on August 9, 2015. Note how sea ice hugs Svalbard’s eastern coastlines. In western Svalbard, however, dense mats of moss, grass, and flowers emerge in the light-filled days of summer.