Residents in Antarctica were recently treated to an unexpected celestial sphere, in the form of noctilucent ice clouds appearing, which resulted in the sky turning electric blue. Noctilucent is the scientific term for “night-shining” which begins every year in the southern hemisphere, but usually it does not occur this early.
PHYS.org reveals that the data came from NASA’s Aeronomy of Ice in the Mesosphere, or AIM, whose spacecraft was recently flying over the location in question. The reason why AIM studies noctilucent clouds, not only in Antarctica but all around the globe, is to gain a better understanding of the mesosphere and the connection it has to other parts of the atmosphere, as well as the earth’s climate and weather.
This observation takes place seasonally, during the summer in both the northern and southern hemispheres. The reason for this is that the mesosphere is most humid during this time of year, due to water vapor rising up from lower altitudes. During the summer season, the mesosphere is also the coldest place on Earth, with the temperature dropping to an extreme low of 210 degrees Fahrenheit. This is the result of seasonal airflow patterns.
The early observation of noctilucent clouds in Antarctica is being attributed to the winter-to-summer changes in the continent’s lower atmosphere, which NASA reports sparked a complex series of atmospheric reactions, one of them being an early night-shining. Research from the AIM has revealed that the noctilucent cloud season has begun as early as November 17 this year, and ranges until December 16. This has broken records in the AIM when it comes to the beginning of night-shining, as it is the earliest start date in history so far.
According to AOL News, the data from AIM has been showing for eight nine years now that a change in one region of the atmosphere can directly affect what happens in another, whether it be near or far. These relationships are referred to by scientists as atmospheric teleconnections. Natural precession has resulted in the spacecraft’s orbit beginning to evolve, which subsequently leads to the measurement of atmospheric gravity waves which researchers believe may be contributing to the teleconnections.
Atmospheric gravity waves occur when fluid returns to its original shape, overshoots and then oscillates, after which time it sets in, propagating as waves. The end result is gravity, or buoyancy, the restoring force that gives the term its name. The waves are a core part of the layering of the upper atmosphere, as they add to the stability of its density.
By Lorelai Zelmerlow
Photo Courtesy NASA