Ice seeding prompted the conversion rate of rain to graupels, reduced the supercooled raindrops and suppressed hailstone growth by accretion.
促进雨霰转化过程，使雹胚浓度增加，并且减少过冷雨滴，抑制冰雹碰冻过冷雨滴的增长；
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Ice crystals are the main sources of graupels, which are produced mainly by auto conversion from ice crystal to graupel and a few grow by collection of ice crystals.