Seed particles, also known as cloud condensation nuclei (CCNs), are tiny solid or liquid particles suspended in the atmosphere that provide the necessary non-gaseous surface for water vapor to condense and transition into liquid droplets, forming clouds. Without these particles, water vapor can remain in a gaseous state even when saturated. Seed particles include natural aerosols like dust, sea salt crystals from ocean spray, pollen, and biogenic aerosols from phytoplankton emissions. Human activities contribute to CCNs through combustion processes releasing soot, sulfates, and other industrial aerosols. These particles act as “landing pads” facilitating cloud droplet formation, influencing cloud properties, precipitation, and thus impacting climate and weather patterns. The presence and characteristics of seed particles are critical in understanding cloud formation dynamics and their role in the Earth’s climate system.
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