Actually, contrails, short for condensation trails, are essentially clouds. They are no different from the cirrus clouds that naturally form in that region of the atmosphere.
事实上，轨迹，简称为压缩痕迹，其本质上是云。他们跟大气层上自然形式的云没什么不同。
2
Such a region is called a condensation and is represented by closely spaced dots .