Discussion»Statements»Rosie's Corner» Clouds form and transform constantly. Can a cloud form travel around the world before it dissipates and disappears? How long do they LIVE?
They move in spiral arcs round revolving weather systems: anticyclones, depressions and the extra-powerful depressions called cyclones (hurricanes). We see them from the ground as apparently going in straight lines because the circulation is hundreds of, perhaps up to a thousand, miles across.
The system itself travels, but generally develops, runs and dissolves within a couple of thousand miles. However, I am writing from being used to a mid-latitude, temperate maritime climate. It is influenced by several thousand miles of land starting beyond the 400-mile wide North Sea to the East, and 3000 miles of Atlantic to the West.
Weather systems and their clouds would be very different in other regions - and practically non-existent in some.
An individual cloud's life can be from days down to minutes.
At one end are the great sheets of overcast in a depression taking a few days to pass. At the other are sweet little fluffy things that form above local convection-currents, grow to maybe a mile or two across, then fade away. I watched this one hot Summer day, and considering their and my locations I guessed the moisture was from beaches about three miles away.
"Sweet little fluffy things..." A sizeable but ordinary cloud can be of thousands of tons of water, as a mass of near-microscopic droplets!
I photographed this unusual bulbous cloud pattern from my home, in Spring two years ago:
WOW! That is a hugely dramatic photo Durdle. Well ya see on Thursday before the rains started here in Hemet, California I was looking at the cloud formations shifting here and there but still maintaining their basic over-all configurations and I thought it was really mesmerizing. They were kinda darkish. I wondered how far they would travel before they went away altogether. I didn't see any "pictures" in them as one often does with the huge white billowy clouds but these were far more dramatic and mysterious. Not sinister. Just eye-catching. Thank you once again for your thoughtful and very informative reply to my question. I guess clouds have intrigued human beings since they were born however many hundreds of thousands of years ago that was. Still do. Happy Saturday to you Durdle! :)
The answer depends on what you mean by "around the world". After all, a cloud travelling around the equator would have a much further journey than one travelling around the 10th parallel (lattitude).
It would have to be wherever Hemet, California is on a parallel or latitude Walt. Circle around the globe at that very same height or however one determines it? Any idea? Thank you for your reply and Happy Saturday! :)
A good point, Walt, but it's more than just distance affecting it.
Clouds are associated with single weather systems in temperate latitudes at least, and except perhaps right by the Poles, these don't encircle the globe. Instead, at their latitudes, the Earth is usually girdled with a series of different systems, depending on whether over an open ocean or a huge continent.
An anticyclone or depression as a whole moves longitudinally and within a fairly narrow latitude band, until it disperses; but its own clouds spiral around its centre.
Co-incidentally, my Internet home-page showed a satellite image of the depression that has just brought very low (for us) temperatures, with snow and ice, across the British Isles. At my rough estimate, that weather system was about 1500 miles in diameter: its easterly edge was over Scandinavia, its Western edge was still well out over the Atlantic. I used as scale, the British mainland itself, roughly 700 miles "high" from the English Channel coast to the North coast of Scotland.
Satellite pictures of those awful hurricanes crossing The Bahamas and Florida, suggest these depressions are of similar diameter, but they are far more powerful. Their origins are over the North African deserts, but if conditions are right for them, they grow as they drift Westwards, picking up vast quantities of extra energy (as heat) and water vapour from the warm Atlantic surface below them as they go.
Durdle 