Dr Chris Barnes: Internet Publications on Optical Atmospheric Phenomena and Weather Forecasting  

Contrail  (or rather persistent contrail) optical phenomena a new weather lore, an eight year study.  By Dr Chris Barnes, Bangor Scientific and Educational Consultants, e-mail scienceconsultants@yahoo.co.uk - July 2013  http://www.drchrisbarnes.co.uk/WXLORE.htm