| Term: | Polar mesospheric clouds |
| Definition: |
Cirrus-like clouds seen from spacecraft over the polar regions during summer in both hemispheres. (Abbreviated PMC.) They occur near the mesopause, at heights of roughly 85 km, and are closely related to noctilucent clouds. AMSglossary
GCW |
| Term: | Polar mesospheric clouds |
| Definition: | Cirrus-like clouds seen from spacecraft over the polar regions during summer in both hemispheres. (Abbreviated PMC.) They occur near the mesopause, at heights of roughly 85 km, and are closely related to noctilucent clouds. |