It has been heretofore understood that patterns of cloudiness are controlled by large scale weather systems. In this video, BJORN STEVENS challenges this orthodoxy, arguing that small and intermediate scales of motion play a key role in determining the Earth’s cloudiness. Using aircraft to measure the vigor of intermediate scales of motion and groups of scientists to examinesmall scale patterning, Stevens identifies distinct patterning of clouds at these smaller scales. He suggests that the role played by small and intermediate scales of motion in cloud patterning is a previously neglected piece of the puzzle which will give us vital insight into how the cloudiness of the Earth might develop in the future.