👉 The Pacific Light Particles, also known as Pacifica particles or PMHs (Polar Mesospheric Halo Particles), are unique, high-altitude ice crystals that form in the mesosphere, the layer of Earth's atmosphere above the troposphere and below the stratosphere, within the polar regions. These particles are primarily composed of water ice but can also contain trace amounts of other substances like ammonia and hydrogen peroxide. They are most prominent during the winter months in the polar stratosphere and upper mesosphere, particularly around the auroral ovals. When sunlight scatters off these ice crystals, they create a spectacular display of light, often appearing as diffuse, glowing streaks or halos around the sun or moon. This phenomenon is a key indicator of atmospheric dynamics and plays a role in understanding the complex interactions between solar radiation, atmospheric chemistry, and climate in the polar regions.
