This helped minimize polar stratospheric cloud
formation in the lower stratosphere.
Chlorine chemistry on polar stratospheric cloud
particles in the Arctic winter.
In any other context, they could have been confused for polar stratospheric clouds
, which are a more common regional/seasonal occurrence approaching such elevated heights.
But the amazing pastel light show is more likely to have been caused by polar stratospheric clouds
, also called nacreous, mother-of-pearl or iridescent clouds.
Such low temperatures are needed for the formation of polar stratospheric clouds
that cause ozone holes over poles (usualy above South Pole).
During the Arctic winter, cool temperatures in the stratosphere form polar stratospheric clouds
However in some occasions due to adiabatic ascent of air masses, stratospheric temperatures drops below the threshold for formation of Polar Stratospheric Clouds
(PSCs), leading to an additional ozone reduction due to chemical processes (Rood et al.
Meteorological officer Renae Baker captured spectacular images of the nacreous clouds, also known as polar stratospheric clouds
, on July 25.
Since late November, large areas of the polar stratospheric clouds
found in the ozone layer have been present over the Arctic region at altitudes of around 20 kilometres, and their geographical extent is probably greater than previously observed.
Polar stratospheric clouds
, which drive ozone loss in Antarctica, turned up in force during the most recent Arctic winter (157: 356*).
Scientists have known for some time that ozone lows are often associated with extremely low temperatures in the stratosphere and the presence of polar stratospheric clouds
, which provide the template for the chemical reactions that destroy ozone.
Using planes and high-altitude balloons, the scientists' goal was to analyze the internal life of the polar stratospheric clouds
that exist at the center of a vortex, a sort of cold giant tornado whose furious winds seal off warm air.