The polar clouds are stormy and persistent, with lifetimes of weeks.

It also made extensive observations of volcanic aerosols and polar stratospheric clouds in the middle atmosphere.

This indicates that control of polar mesospheric clouds is determined by geographical rather than geomagnetic factors.

Another method considered for producing the warm polar temperatures were polar stratospheric clouds.

Another requirement for polar stratospheric clouds is cold temperatures to ensure condensation and cloud production.

The polar stratospheric clouds had a warming effect on the poles, increasing temperatures by up to 20 C in the winter months.

A multitude of feedbacks also occurred in the models due to the polar stratospheric clouds' presence.

Separate model runs were used to determine the sustainability of the polar stratospheric clouds.

These conditions result in the best environment for the formation of polar mesospheric clouds.

First, the low temperatures lead to the formation of polar stratospheric clouds, which are high-altitude.