Earliest Ever Arrival Of Night Shining/Noctilucent Clouds Mark Onset Of Summer In Antarctica, NASA’s AIM Spacecraft Confirms
2016 recorded the earliest arrival ever of the noctilucent clouds in the Antarctica. The data obtained from NASA's Aeronomy of Ice in Mesosphere spacecraft (AIM) confirmed the start of night shining cloud season earlier this week.
The spacecraft also sent images of the Antarctic sky, as seen from space. The sky radiated electric blue color when sunlight is reflected off the ice crystals in the clouds. Experts are trying to link the early onset of night shining to early arrival of summer in the Antarctica, which is a matter of concern for climatologists and NASA.
Night shining clouds or noctilucent clouds are the highest, wettest and coldest clouds of Earth. They are literally sandwiched in between the atmospheric layers and space, lying at around 50 miles above the Earth's surface in the mesosphere.
As a general phenomenon, they are formed at the onset of summer in both Northern and Southern hemispheres. The water vapors rising from below are deposited around the dust and micro-debris coming from the space from meteors and shooting stars and ice crystals are formed. These ice crystals shine when sunlight falls on them and glow.
This glow can be easily observed from the space, when the sky over Antarctica turns luminescent with electric blue color. NASA notified the earliest ever onset of night shining cloud season on Dec. 2, 2016. The composite satellite images showed that the sky over Antarctica turned electric blue on Nov. 17, 2016, which is earliest since the AIM spacecraft was launched.
Usually, night shining season starts in late November or early December. But this year, experts are proposing the change in pattern may be a result of seasonal changes at lower altitudes in Antarctica.
As per a article recently published in Phys.org, changes in the winter to summer transition in the lower atmosphere triggered a whole range of modifications in the temperature and moisture levels in the upper atmosphere. This phenomenon is referred to as the "atmospheric teleconnection."
Scientists are yet to confirm the cause of this change in pattern of night shining clouds, but there are speculations that this may be as a result of global warming. Additionally, the impact of this change on the melting of Antarctic polar ice cap is still ambiguous.
In an attempt to decipher the underlying causes and impacts of atmospheric teleconnections, the NASA AIM spacecraft started measuring the atmospheric gravity waves, which may be highly helpful in providing information regarding upper atmospheric changes and their lower atmospheric outcomes.