Freezing Rain
Overview
Freezing rain is a weather phenomenon that occurs during early winter or the transition period between the end of winter and the beginning of spring. When a strong cold air mass moves southward and encounters warm, moist air, the cold air acts like a wedge, inserting itself beneath the warm air. This causes the near-surface temperature to drop sharply below zero degrees Celsius. The warm, moist air is lifted upward, forming clouds and precipitation. As the raindrops fall from the sky, due to the extremely low temperatures near the ground, they freeze upon contact with power lines, trees, vegetation, and road surfaces, forming a thin layer of crystal-clear ice. In meteorology, this weather phenomenon is referred to as "freezing rain." In some areas of southern China, freezing rain is also called "ice needles," while in northern regions, it is known as "ground grease." Raindrops that instantly freeze upon contact with the ground, objects such as trees, wires, or airplanes, are termed freezing rain. These raindrops fall from the sky as supercooled water droplets with temperatures below 0°C. Upon contact with branches, power lines, dry grass, or other ground-level objects, they freeze into a smooth, transparent layer of ice on these surfaces. Sometimes, the ice forms while still flowing, resembling icicles. In meteorology, this layer of ice is also referred to as "glaze ice" or simply "icicles." Freezing rain occurs when supercooled raindrops or drizzle fall onto surfaces with temperatures below the freezing point, quickly forming transparent or semi-transparent ice layers. This can create magnificent scenery described as "thousands of cliffs encased in icy jade and millions of peaks crystallized in glass-like beauty." When drizzle occurs, granular glaze (graupel) forms, which has a rough surface and clearly visible granular structure. When larger raindrops or heavy rainfall occur, clear-glaze ice forms, which is smooth, transparent, and dense. This type of ice often flows and freezes simultaneously on power lines, tree branches, or ship decks, creating long icicles. Freezing rain mostly occurs during winter and early spring. In China, Guizhou Province experiences the most frequent occurrences of freezing rain, followed by Hunan, Jiangxi, Hubei, Henan, Anhui, Jiangsu, Shandong, Hebei, Shaanxi, Gansu, and southern Liaoning, with mountainous areas seeing more occurrences than plains, and high-altitude mountains experiencing the most. Can raindrops falling from the sky and freezing cause harm? Yes, when this ice accumulates to a certain extent, not only does it cause harm, but the damage can be significant.