Ispartikler

Ispartikler, or ice particles, are small particles consisting primarily of ice. In atmospheric science they refer to microscopic solid water crystals suspended in the air or forming part of clouds. They range from a few micrometres to a few millimetres in size and can occur alone or as components of snow, sleet and hail.

Formation and growth. Ice particles form when water vapour deposits directly as ice (deposition) or when supercooled liquid droplets freeze upon contact with a nucleus (riming). They can also grow by aggregation, where multiple crystals collide and stick together. Growth is governed by temperature, humidity, and the presence of freezing nuclei.

Morphology and conditions. Ice crystals assume a variety of shapes, most commonly hexagonal forms such as plates and columns, with dendritic, fern-like branches at certain temperatures. The exact habit depends strongly on ambient temperature and supersaturation.

Occurrence and role. Ice particles are common in high-altitude cirrus clouds and in deep, cold clouds; they play a key role in Earth's radiation budget by scattering and absorbing sunlight and infrared radiation. They are central to precipitation processes: riming, aggregation and accretion lead to snow, graupel or hail. In addition to natural clouds, ice particles can be produced in laboratories for research.

Observation and study. They are observed with optical particle counters, imaging probes, lidar and radar, and collected via in situ sampling on aircraft or ground-based cold chambers. Climate models incorporate ice microphysics to simulate cloud behavior and climate feedbacks.