Comment The unique landscape at the Rock of Gibraltar is home to amazing flora and fauna found nowhere else on the European continent — and is also home to the rare Levanter cloud, which follows the craggy summit of the lonely rock. Video from Gibraltar Met Office shows a stunning lavender cloud – named after the Levant wind that blows east over the local terrain – seemingly formed from thin air. In fact, the formation of the cloud is not miraculous – it is a by-product of the Levant wind and the extreme landscape. Moist surface air is pushed up by the sudden spike in the topography and rises to a height where the temperature is cooler than the dew point of the surface air. This means that the air reaches saturation and the moisture in it condenses, forming a cloud. In front of where the Levanter regularly forms is Gibraltar International Airport, where passenger jets and helicopters land with a rare and stunning view, even on cloudy days. Some on the island have begun to see the shapes of animals in the unusual cloud, which can only form when the Levant winds blow. According to the UK’s Royal Meteorological Society, the wind can blow at any time of the year, but is most common from June to October. Levanter cloud is a special subset of a more common cloud type – orographic clouds, meaning clouds formed by the topography of the Earth. In the type of orographic clouds there are several types of clouds, namely banner clouds and lenticular clouds. A saucer-shaped cloud lights up the sky in California Levanter is best classified as a type of banner cloud, a cloud that forms from the top of isolated, steep mountain peaks when the winds are strong. The Rock of Gibraltar is a perfect place for them to form, but such clouds can also be seen on peaks such as Everest in the Himalayas and the Matterhorn in the Alps. Lenticular clouds are some of nature’s strangest. Shaped like a lens – or flying saucer – these rare clouds can be spotted near or on top of the mountains themselves, so it’s known as a “cap” cloud. Lenticular clouds form when moist air is driven to the top of the mountain and cooled to the point of saturation, whereupon it condenses into a cloud. Unlike clouds that flow across the sky, a lenticular cloud takes on its unique shape when moist air sinks after climbing the mountain and dries out, leaving a smaller, saucer-shaped cloud. The orographic lift can also create unique climates on and around the mountains. On the windward side of the great mountains, where rising moist air condenses into dense clouds, a lot of rain and snow can fall, keeping the windward side lush and green. However, the air that remains over the mountain to the leeward side is devoid of most of its moisture, leaving the leeward side of the mountains high and extremely dry. Arid climates tend to form on the leeward side of mountains, home to famously arid locations such as California’s Death Valley and Chile’s Atacama Desert. Matthew Cappucci contributed to this report.
