Stunning Cloud Formations: Kelvin-Helmholtz Billows
Source: Nascent Array
These playful, wave-like cloud formations are formed when turbulence develops in a cirrus cloud that has two different layers of air moving at different speeds. Named after Lord Kelvin and Hermann von Helmholtz, these clouds indicate atmospheric instability, and are easily identifiable due to their evenly spaced peaks and falls that resemble waves. The cloud formation is said to have influenced Van Gogh’s Starry Night.
Source: Old Sarum Airfield
Source: Nascent Array
Source: Wikimedia Commons
Noctilucent Clouds
Source: Live For The Outdoors
Noctilucent clouds are Polar Mesospheric Clouds (PMC) that consist of many minute ice crystals. They are most visible during the summer in the morning or at deep twilight, low in the northern sky. Though they are a rare cloud formation, they seem to be forming more often as time progresses and the climate changes. These bright clouds with ragged edges are only visible when the sun illuminates them from below the horizon.
Source: Space Weather
Source: Aberdeen Astro
