Noctilucent Mystery

21 Jun 2019

The prevalence of noctilucent clouds in June has sparked a lot of response from blog authors, mostly as a result of visiting http://spaceweather.com (post on June 19th 2019) ... which has the title 'mysterious moisture in the mesosphere' and its effects on noctilucent clouds. Their providence as far south as Los Angelese in California and Albuquerque in New Mexico (as well as repeated reports from Poland and Germany) make this year unusual to say the least. The mesosphere is very wet is the message that has been spread abroad - the wettest it has been for 12 years (which roughly corresponds to the solar minimum prior to the current solar cycle). Not as dramatic as it is being presented then, but nevertheless interesting as noctilucent clouds have not earned too much attention in the past from media sources.

   ... Noctilucent clouds form when summertime wisps of water vapour rise to the top of the atmosphere. Water molecules then attach themselves to specks of meteor smoke and gather into icy clouds that glow electric blue when hit by high altitude sunlight. It is thought that planetary waves may be to blame for the extra moisture in the mesosphere (according to at least one atmospheric scientist) - transporting cold air and high water vapour to the noctilucent zone. However, the author of the piece notes we are in deep solar minimum and ultraviolet radiation that would normally destroy water in the mesosphere is currently at a low ebb.

At http://spaceweather.com (June 21st) the subject is sprites - and what are called palm sprites as they are so tall and can be seen over Texas above an electric storm (see below) ...

   ... in times of yore a lot of this natural phenomena would have been seen but not necesssarily believed but thanks to modern gadjets and technology an image today can be flashed around the world in next to no time.