While exploring Opera Blogs I noticed a pleasing effect with their picture viewer and decided to see how well it shows a cartoon of the North Atlantic over a spell. …
I use the term spell as meant by physicists. Meteorologists speak quite naturally of spells of weather. It is probably where the puritanical get the idea that spells are associated with witchcraft.
It is more likely that witchcraft was associated originally with science. It is only today that it has become the subject of priest craft, in my opinion less damaging than State religions.
But for me a "spell" is merely the time of the phase of the moon under which the phenomena see as storms above and below the surface of the earth take place.
The first is for the North Atlantic at six o'clock in the morning.
The second six hours later, at noon.
And the third at six in the evening.
"H" refers to regions of high pressure (Highs or Anticyclones) the one at bottom centre is the Azores High. It is a well known feature the USA and Canadians call it the Bermuda High. In all the above it is at 1035 mb (millibars) that equates to 30.5 inches of Mercury (Very Dry on a barometer legend.)
It can go past 1060 mb which is a column of air with a cross section of 1 square inch at the base, 60 miles high. Or a sheet of lead over 31 inches thick.
The atmosphere is even better at dealing with radiation than lead as it can react with it. Lead and mercury merely absorb it. (Air is tranparent to visible light, translucent to infra red and reacts with or reflects UV. It will even have a physical/chemical reaction with it, creating radio active elements in the process.)
The Low pressure areas (L = cyclones) are the most interesting. They feed heat to the West of Europe. They cross North America from Oregon and California are forced over the Rockies where they may become Highs and leave usually from somewhere between Georgia and Newfoundland.
Sometimes they enter the continent via the Gulf of Mexico, in which case they may follow the rockies until they fill up the basin of the the plains and head east or they may join the other weather and run up the Appalachians and exit tute suite.
In all cases their leaving is accompanied by seismic effects over several regions all of which are some 80 degrees distant.
And that is enough for now. Here is some more