【摘要】 通过分析云的含水量表明 :①全球的云中含水量约为 90× 1 0 9t,与大气中气体状态的水汽比 ,不足其 1 % ,在计算大气总含水量时可以忽略 ;②积雨云含水分丰富 ,但是计算显示它持有的水分也少于 3mm。③由于云的含水量很小 ,而每年有 1 0 0 0mm的雨雪从云中降落 ,所以云中的水分循环很快 ,从成云到致雨 (雪 )不足 2h。更多还原

【Abstract】 The calculation and analysis indicte that:(1)The total water content of global cloud is nearly 90×10 9t,which is less than 1% comparing with the global vapor. So when calculating the amount of globe atmospheric water, the cloud water content can be ignored;(2)Cumulonimbus is abundant of water,but calculation shows that its precipitable water is less than 3 mm;and (3)There are 1 000 mm water precipitated from the cloud every year, but the precipitable water of cloud is exiguity,so water circulation is very quickly.The duration of a water element from the beginning of cloud to landing as rain is less than 2 hours.更多还原