Satellite eye on Earth: December 2015 – in pictures

Mount Etna erupting, Super Typhoon Melor, and snow-free mountains of New York were among the images captured by European Space Agency and Nasa satellites last month

In late December strong winds carried dust from the Sahara desert westward over the west coast of Africa and the Canary Islands. This image, taken on Christmas day, shows the stark contrast between the tan dust and the deep blue of the Atlantic Ocean. In some areas the dust is so thick that the ocean is completely obscured. The Canary Islands are a volcanic archipelago with steep mountains that can affect the flow of wind. When wind strikes such an immobile object, turbulence is created as the forward-moving wind is re-routed to the side. Immediately behind the leeward side of the object, the air is often still, while wave-like patterns are created in the area of turbulence - as seen around the islands of Tenerife (west), Grand Canaria, and Fuerteventura (east) in the image. Tenerife is home to Mount Teide, an active volcano which rises to 3,718 metres (12,198 feet) above sea level. It is the highest point above sea level in the islands of the Atlantic, and the highest point in Spain. The massive mountain has strongly interacted with the wind, leaving a wide dust-free zone on its leeward side.