Interestingly, while the bases of stratiform clouds  are generally flat, they tend to develop significant features at the top due to wind and  temperature changes.

有趣的是， 虽然层状云的底部通常是平坦的，但由于风和温度的变化， 它们往往会在顶部形成明显的特征。

Now, Asperitas clouds are  thought to be mostly a supplementary feature of stratiform clouds, which are low elevation  layered clouds without vertical development, although asperitas have also been observed to  be stratocumulus or altocumulus.

现在， 佩里塔云被认为主要是层状云的补充特征，层状云是低海拔层状云， 没有垂直发展，尽佩里塔也被观察到是层积云或高积云。

While stratiform clouds  often have what is known as Kelvin-Helmholtz instability at the top, an instability that  comes from a velocity shear within fluids, this instability is more unusual at the base of clouds.

虽然层状云的顶部通常存在所谓的开尔文-亥姆霍兹不稳定性，这种不稳定性来自于流体内的速度剪切，但这种不稳定性在云的底部更为不寻常。