Most of the clouds and weather we are used to happens in the first eight miles of the Earth’s atmosphere, called the troposphere.
Above this layer, the air is much thinner and we find a very different composition. We find layers of intense cold that can produce rare and dramatic clouds and we see one of Nature’s most incredible optical phenomena, the aurora.
As we climb from ground level, it gets colder. Air pressure and density also fall until we reach the tropopause. This acts as a barrier between the troposphere and the stratosphere, where temperature increases with height.
Temperatures can be as cold as -121 degrees Fahrenheit in the lower stratosphere. These conditions give us ultra-bright polar stratospheric clouds and colorful nacreous clouds.
Nacreous clouds are also called mother-of-pearl clouds because they blaze unbelievably bright with iridescent colors. These are frequently seen at higher latitudes in the winter.