Hi John,
Thanks for the picture. According to The Telegraph: Meteorologists refer to them as NLCs or "polar mesospheric clouds". This is because they form right on the boundary of the mesosphere (between the stratosphere and space). The mesosphere is dry and cold (about -123°C), unlike the warm, moist troposphere below, where all the other clouds form. These noctilucent clouds are composed of tiny ice crystals – a fiftieth of the width of a strand of human hair. Noctilucent clouds are on the increase – there are twice as many as there were 35 years ago and they're moving south: a visible result of global warming. [End quote] I'd like to think that somebody is taking our concerns for global warming and Arctic sea ice seriously, and quietly experimenting with stratospheric sulphate aerosols. But the more likely explanation is ice, as described above by The Telegraph. Cheers, John John Gorman wrote: > interesting bit in UK Telegraph about strange cloud phenomenon last week > noctilucent clouds at about 50miles > anyone know whether they are likely to be sulphuric acid aerosol? > John Gorman > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
