Polar stratospheric clouds over silhouetted trees at sunset. These are the nacreous or mother-of- pearl type of polar stratospheric cloud (PSC). PSCs are high-altitude icy clouds that are found in the polar stratosphere at heights of about 24 kilometres. They only form during winter when the temperature drops below around -80 degrees Celsius. PSCs play a key role in the destruction of ozone by chlorine. They convert harmless forms of chlorine into highly-reactive forms. Chlorine is carried into the stratosphere in CFCs (chlorofluorocarbons),gases used as refrigerants and during foam plastic manufacture. Photographed over Swedish Lapland | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Hay Jones, David |
Bildgröße: | 3213 px × 4432 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |