At www.gks.uk.com/Apophis-Apep-Serpent/ it is suggested the jet streams were anciently more visible and they were likened to encircling serpents in the sky. This idea is another twist in interpretation of myth. We have had comets as sky dragons and aurora as undulating serpents and now we have the jet stream as an alternative. These are narrow currents of air between the troposphere and the stratosphere, the web site says, and they were more pronounced in the past as a result of dust and debris captured in the upper atmosphere. We may not that in 2010 the movements of the sub polar Jet Stream brought flooding to Pakistan, a heat wave to parts of Russian (in the summer) and an early cold blast to Europe (in late autumn), and it has continued into 2011 as it is responsible for a cold spring in North America and Eurasia (but a hot and dry spring in NW Europe).