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iapennell

IF THE EARTH ROTATED AT JUST HALF THE CURRENT RATE- BRITAIN WOULD HAVE EXTREME WEATHER

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Just a thought:  IF ONLY the Earth rotated on its axis at half its current speed (i.e there were just 183 48-hour days each year) Britain would have much more extreme weather.  For starters the long, long days of Summer would get hot given clear skies but clear nights (with a 16-hour period without the Sun) would get colder.  The slow rotation of the Earth would have other implications in that the NE and SE Trade winds in low latitudes would be less affected by the Coriolis Effect and would come in more directly from north and south respectively; the easterly component of Trade Winds would be swamped by the stronger heating/cooling of land-masses on a diurnal basis crating stronger sea-breezes with westerly (as well as easterly) components.  Hence the need for Westerlies in higher-latitudes to counterbalance tropical and polar easterlies (to satisfy Conservation of Angular Momentum laws) would be much-reduced and so blocking-highs with cold north or north-east winds would be much more frequent in the winter-half-year in the latitudes covered by Britain:  Depressions would often be confined to the North Atlantic and they may still be intense but small in area of extent; it would more often be the case that blocking highs in the Arctic would entrench cold over Europe so that moisture would only come up against very cold air leading to snow over Britain, France and Norway.

This set-up would lead to frequent frigid NE winds, clear skies and extremely low-temperatures occurring during the 32-hour long winter nights, occasional snowfalls would lead to a covering of snow reflecting away the weak sunshine during 16-hour winter days so they would still be very cold.  The Arctic would be a bit less cold than nowadays in winter owing to the more-persistent loss of cold airmasses (compared to nowadays) but clear skies with 48-hour darkness each day would counterract this to some extent by strengthening radiative heat loss.  For Britain, persistent NE winds from the Russian Arctic would still lead to the North Sea freezing over and clear still nights would lead to widespread minima below -40C (-50C in parts of Scotland). Both day and night would be below -20C across the entire country in December and January.

Spring would warm slowly with prevailiing icy NE winds maintaining the reflective snow-cover and the frozen North Sea would only slowly thaw and warm up: Typical April conditions would be long nights falling to -25C in Manchester and -30C in the upper Dee Valley in Aberdeenshire with longer sunny days but with icy NE winds reaching 5C in Manchester and -5C in the upper Dee Valley (Aberdeenshire), so the snow would thaw very slowly from the lowlands (freezing at night largely undoing this).

The subtropical high would form further north in summer because a strong subtropical jet would then struggle to form south of 50N; this would guarantee more fine and sunny weather in summer with the very long sunny days getting really hot but the still long hours of night getting cold and causing ground-frost in southern Britain.  Hot days above 30C would be widespread but close to the North Sea (which would still be cold after being frozen hard in winter) sea breezes would ensure maxima above 15C were a rarity in places like Bridlington and Berwick on Tweed.  Minima below 0C would be common in the Peak District, the Yorkshire Dales and in much of Scotland and permafrost would be extensive across the North Pennines and much of inland Scotland.  Rain would be unknown in the summer months and savage-drought would be the normal state of affairs over Britain.

The change of the radiation balance to negative in September would be associated with less wind and rain but more high-pressure from Arctic Scandinavia:  Hard night frosts would return with avengeance with more than 24 hours uninterrupted strong radiation cooling on clear nights with icy NE airstreams; temperatures below -10C would occur at times almost anywhere.  Long sunny days of almost 24 hours would be 15 to 20C with light NE winds across the English Midlands, much colder in Scotland and NE England though. 

October with weaker sun and even longer nights would bring days (as well as nights) below freezing point though occasional depressions pushing into the west would yield occasional snowfalls as milder Atlantic air pushes against cold air over Britain [the North Atlantic would not be so mild; cold airmasses from the Arctic would cross it more frequently whilst warm air from south of 45N will rarely reach it because the subtropical high-pressure belt would be forming much further north- as such the North Atlantic Drift would no longer bring warm surface waters from the Gulf of Mexico]. So October would get very cold quickly with snow-cover established over the whole of Britain (not a lot though because cyclonic activity would be infrequent); nights below -30C would occur on the stillest very-long nights following more direct Arctic blasts in Scotland and parts of northern England by the end (the 15th) of October. And so another long brutal winter would set in across Britain; by November the North Sea would have frozen over entirely........

Now, if only we could find a way of halving the Earth's rate of rotation!!!

 

   

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... And humanity would be in dire straits from earthquakes/volcanoes and floods. I'll pass on that one!

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That sounds fun.. well parts of it lol.

But would it really be that extreme?

That winter description sounds like the prevailing westerlies are reversed, rather than just half as strong on average.

I wonder how much colder nights would actually get, because on a typical clear night the temp falls fastest during the first few hours then slows (forgotten the name of this effect), so may only fall a couple degrees in the 2nd half of the night. I reckon doubling night length would only drop the temp a few degrees more in any night with the same starting point. The same seems to be true for maxima with solar heating to some extent, you hit a point where the lapse rate becomes too great and you need more wholesale heating of the atmosphere to make the temp continue to rise that fast (otherwise it cools via convective mixing), which requires much more time/energy (compared to just removing the previous night's relatively shallow inversion).

Of course, halving the Earth's rotation speed and associated changes in ocean/atmospheric circulation would likely change our 'baseline' climatic conditions.. It may even initiate a glaciation.. I don't know.

However.. speculating more, I think with the outward/centrifugal force due to Earth's rotation halving.. the Earth would become more circular.. with it currently having an equatorial bulge of 26.58 miles, I'm guessing the change would lead to massive earthquakes/volcanic eruptions etc as the Earth readjusts, or maybe the more fluid oceans would readjust first and flood polar areas while the sea drains a lot for more equatorward areas.. So in reality, much of Britain may be flooded!

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1 hour ago, Evening thunder said:

That sounds fun.. well parts of it lol.

But would it really be that extreme?

That winter description sounds like the prevailing westerlies are reversed, rather than just half as strong on average.

I wonder how much colder nights would actually get, because on a typical clear night the temp falls fastest during the first few hours then slows (forgotten the name of this effect), so may only fall a couple degrees in the 2nd half of the night. I reckon doubling night length would only drop the temp a few degrees more in any night with the same starting point. The same seems to be true for maxima with solar heating to some extent, you hit a point where the lapse rate becomes too great and you need more wholesale heating of the atmosphere to make the temp continue to rise that fast (otherwise it cools via convective mixing), which requires much more time/energy (compared to just removing the previous night's relatively shallow inversion).

Of course, halving the Earth's rotation speed and associated changes in ocean/atmospheric circulation would likely change our 'baseline' climatic conditions.. It may even initiate a glaciation.. I don't know.

However.. speculating more, I think with the outward/centrifugal force due to Earth's rotation halving.. the Earth would become more circular.. with it currently having an equatorial bulge of 26.58 miles, I'm guessing the change would lead to massive earthquakes/volcanic eruptions etc as the Earth readjusts, or maybe the more fluid oceans would readjust first and flood polar areas while the sea drains a lot for more equatorward areas.. So in reality, much of Britain may be flooded!

It is certainly true that if the Earth's rotation was halved instantaneously the oceans would pile up over the Arctic -to a depth of 10 miles whilst the tropics would become, in effect a giant continent reaching several thousand metres above sea level- so high infact that extensive areas would become cold enough for snow to fall and accumulate over extensive areas.  This would be encouraged by extensive atmospheric convection during long hours of daylight with the Sun almost overhead for several hours each day.  There would, of course be massive volcanoes in the process as the magma and molten outer core adjusted to the change in the rate of the Earth's rotation, this process would take thousands of years (parts of Scandinavia are still rising after the effects of glaciation during the last Ice Age which ended over 10,000 years ago).  Southern Britain will still (just) be above sea level but the North would be inundated by a much-enlarged Arctic Ocean which, cut off from warm currents from the subtropics (and warm winds- see above post) would quickly freeze over in winter and remain frozen!

With frozen ocean everywhere polewards of 52N (and 52S- Antarctica would be submerged) and very high areas in the tropics getting permanent snowcover and desert almost everywhere else (without depressions until one reaches 50 degrees North and South locations always away from the Intertropical Convergence Zone will get no rain (or snow) the albedo of the Earth's surface will rise substantially [subtropical deserts reflect more heat than subtropical oceans].  The massive volcanoes would throw out so much dust and sulphur dioxide into the stratosphere there would be a substantial (even bigger) reduction in the Sun's energy reaching the surface of the Earth.  The new (extended) Arctic and Antarctic Oceans would have permanent thick pack-ice; lower latitudes would have massive temperature swings between severely freezing mid-winter nights and hot summer days (and no rain) whilst the high Equatorial regions would be permanently bitterly cold (with daytime snowfalls when the ITCZ passes by), low equatorial areas (currently under tropical oceans) would have blistering hot days with little rain (if any) but cold clear nights.  It would be like Earth returning to something akin to the most severe coldest years out of any of the last run of Ice Ages and mean global surface temperatures would be close to 0C.

One has to say that, even without the effects of volcanoes and major adjustments to sea levels between the tropics and poles, the climatic conditions could be very severe outside of the deep tropics- almost no rain could fall outside the ITCZ but equatorwards of the latitudes of Paris or Vancouver- even in winter.  In high latitudes there would be less precipitation but without real warm-air advection it would almost always fall as snow so ice-sheets over Greenland and Antarctica would probably alter little. Almost all high and mid-latitude continents would have extreme winter cold due to persistent high-pressure and clear skies, combined with a prevailing drift of air from the highest latitudes.  Islands in the North Atlantic (north of 50N) would still have short periods of westerlies (the Coriolis effect would still be strong enough in high latitudes to cause winds to blow more or less around the low-pressure systems that would still occur) but the air would never be coming from much further south than 50N so these winds would be cold, and frequent surges of frigid air off the Greenland Icecap would bring bitter north-NW winds from autumn through spring. Because of this and because of the absence of a North Atlantic Drift most of the North Atlantic north of about 55N would be pack-ice by March.  

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It's also true that Earth's rotation is slowing down: very slowly, the tidal forces of the moon have slowed our rotation - so, aye, eventually a day will last for 48 hours. That is, unless the sun goes nova before then?:D

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Just now, Ed Stone said:

It's also true that Earth's rotation is slowing down: very slowly, the tidal forces of the moon have slowed our rotation - so, aye, eventually a day will last for 48 hours. That is, unless the sun goes nova before then?:D

Indeed, the tidal forces of both the Sun and Moon have this effect, as do occasions in winter when the Arctic gets very cold and the stratospheric circumpolar Westerlies get strong- and some of this air escapes to space leading to a permanent loss of a small amount of atmospheric Westerly momentum.  Its likely to take one billion years before we reach that point however, by which time the Sun will be about 10% stronger than now (as it progresses towards Red Giant stage) and the continents moved away from high latitudes.  In which case there may not be extremely severe winters at high latitudes, let alone permanent ice caps!  Depends how much the loss of warm-air advection to high latitudes is compensated for by radiative forcing (plus positive feedbacks caused by the loss of high latitude snow/ice cover in summer)- the air descending in high latitude anticyclones would have originated as extremely hot air in a stronger ITCZ so even with long clear winter nights the ambient temperature of the descending air would not be conducive to temperatures falling to -40C.

However if the Sun takes longer to increase in power and the Earth's rotation halves a bit quicker (say it takes just 500 million years due to a series of Ice Ages with extensive easterly winds over the globe) then the above scenario could well play out!

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kind of refutes some of what the OP suggests and agrees in other areas, but fun viewing all the same

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6 minutes ago, iapennell said:

Indeed, the tidal forces of both the Sun and Moon have this effect, as do occasions in winter when the Arctic gets very cold and the stratospheric circumpolar Westerlies get strong- and some of this air escapes to space leading to a permanent loss of a small amount of atmospheric Westerly momentum.  Its likely to take one billion years before we reach that point however, by which time the Sun will be about 10% stronger than now (as it progresses towards Red Giant stage) and the continents moved away from high latitudes.  In which case there may not be extremely severe winters at high latitudes, let alone permanent ice caps!  Depends how much the loss of warm-air advection to high latitudes is compensated for by radiative forcing (plus positive feedbacks caused by the loss of high latitude snow/ice cover in summer)- the air descending in high latitude anticyclones would have originated as extremely hot air in a stronger ITCZ so even with long clear winter nights the ambient temperature of the descending air would not be conducive to temperatures falling to -40C.

However if the Sun takes longer to increase in power and the Earth's rotation halves a bit quicker (say it takes just 500 million years due to a series of Ice Ages with extensive easterly winds over the globe) then the above scenario could well play out!

worth noting that in around 500 million years time, it's theorized that the earth will be considerably warmer than it is now and the atmosphere considerably denser due to the start of ocean evaporation allowing billions of tons of water vapour released into the atmosphere leading to a runaway greenhouse effect....almost certainly no location on the planet falling to 0C, with 'hypercanes' ruling the roost weatherwise, with a pangea type supercontinent containing just all about all of earth's landmass

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I would love the idea of 2 year orbit of sun (current distance) longer winters /summers.

 

 

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When it got to the point where the Coriolis Effect causes easterly wind-patterns in the southern hemisphere, I called it a day...Since when do the Roaring Forties blow from the east?:cc_confused:

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42 minutes ago, ajpoolshark said:

 

kind of refutes some of what the OP suggests and agrees in other areas, but fun viewing all the same

Half way through good watch thanks for putting it up.:)

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1 hour ago, iapennell said:

It is certainly true that if the Earth's rotation was halved instantaneously the oceans would pile up over the Arctic -to a depth of 10 miles whilst the tropics would become, in effect a giant continent reaching several thousand metres above sea level- so high infact that extensive areas would become cold enough for snow to fall and accumulate over extensive areas.  This would be encouraged by extensive atmospheric convection during long hours of daylight with the Sun almost overhead for several hours each day.  There would, of course be massive volcanoes in the process as the magma and molten outer core adjusted to the change in the rate of the Earth's rotation, this process would take thousands of years (parts of Scandinavia are still rising after the effects of glaciation during the last Ice Age which ended over 10,000 years ago).  Southern Britain will still (just) be above sea level but the North would be inundated by a much-enlarged Arctic Ocean which, cut off from warm currents from the subtropics (and warm winds- see above post) would quickly freeze over in winter and remain frozen!

With frozen ocean everywhere polewards of 52N (and 52S- Antarctica would be submerged) and very high areas in the tropics getting permanent snowcover and desert almost everywhere else (without depressions until one reaches 50 degrees North and South locations always away from the Intertropical Convergence Zone will get no rain (or snow) the albedo of the Earth's surface will rise substantially [subtropical deserts reflect more heat than subtropical oceans].  The massive volcanoes would throw out so much dust and sulphur dioxide into the stratosphere there would be a substantial (even bigger) reduction in the Sun's energy reaching the surface of the Earth.  The new (extended) Arctic and Antarctic Oceans would have permanent thick pack-ice; lower latitudes would have massive temperature swings between severely freezing mid-winter nights and hot summer days (and no rain) whilst the high Equatorial regions would be permanently bitterly cold (with daytime snowfalls when the ITCZ passes by), low equatorial areas (currently under tropical oceans) would have blistering hot days with little rain (if any) but cold clear nights.  It would be like Earth returning to something akin to the most severe coldest years out of any of the last run of Ice Ages and mean global surface temperatures would be close to 0C.

One has to say that, even without the effects of volcanoes and major adjustments to sea levels between the tropics and poles, the climatic conditions could be very severe outside of the deep tropics- almost no rain could fall outside the ITCZ but equatorwards of the latitudes of Paris or Vancouver- even in winter.  In high latitudes there would be less precipitation but without real warm-air advection it would almost always fall as snow so ice-sheets over Greenland and Antarctica would probably alter little. Almost all high and mid-latitude continents would have extreme winter cold due to persistent high-pressure and clear skies, combined with a prevailing drift of air from the highest latitudes.  Islands in the North Atlantic (north of 50N) would still have short periods of westerlies (the Coriolis effect would still be strong enough in high latitudes to cause winds to blow more or less around the low-pressure systems that would still occur) but the air would never be coming from much further south than 50N so these winds would be cold, and frequent surges of frigid air off the Greenland Icecap would bring bitter north-NW winds from autumn through spring. Because of this and because of the absence of a North Atlantic Drift most of the North Atlantic north of about 55N would be pack-ice by March.  

 

If you halved the Earth's rotation instantaneously, you and I and anything else not securely fastened to the surface would get flung forward at approximately 835km/h on the equator and 639 km/h at 50N. That includes the atmosphere. So I wouldn't be worrying too much about what the weather was going to be like. :D

Slow it by say 1% a year though and it's an interesting thought experiment. I've no doubt it's been tested with a GCM at some point.

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45 minutes ago, ajpoolshark said:

 

kind of refutes some of what the OP suggests and agrees in other areas, but fun viewing all the same

Gosh, that is most interesting having watched it: Agree with the point about two polar oceans, but disagree profoundly that the Roaring Forties in the southern Hemisphere would just become easterly if the Earth stopped rotating.  The narrator suggests violent storms would affect large parts of the Earth whereas, outside of the Intertropical Convergence Zone all storms depend on the Earth's rotation, lessen this and you get less storms.  Snowfalls would be restricted to higher latitudes and new upland areas near the ITCZ (by day) in low latitudes.  Blizzards and snowstorms at night in Miami are, therefore, unlikely.  The long nights with strong surface cooling would be associated with clear skies.

If the Earth rotated very slowly, say length of day equal to a fortnight today there would be a single thermally-direct cell in each hemisphere with winds blowing from high latitudes to the Equator and with winds blowing (to some extent) from the night side of Earth to the day side in low latitudes. So little westerly momentum would be transferred to poleward moving high-latitude air that the sinks for this would need be no more than a) high latitude mountain ranges and b) occasional convective downdraughts (with a westerly element) in north-northeasterlies by day over mid-latitudes (south-southeasterlies in mid southern latitudes). Rain or snow would be absent from mid and high-latitudes, especially in winter!

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It's not quite as clear as the original thought experiment makes it seem. Theory and modelling shows that actually, slowing the earth's rotation leads to a warming at higher latitudes and slight cooling of the tropics such that the equator-pole temperature gradient is reduced. The jet stream and westerly winds increase in strength and shift northwards of the UK. By 72 hour day length the meridional Ferrel cell circulation ceases and the Hadley cell reaches 40-50°N ie southern UK would be bordering on subtropical region. Beyond a 144 hour day length there is a single tropic to polar Hadley cell circulation reaching 70°N and the jet now confined to the high Arctic weakens with greatly reduced available angular momentum - see eg

 http://www.gfdl.noaa.gov/bibliography/related_files/ann0201.pdf 

https://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Hadley-cell/2-Showman-2009.pdf

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I have had a read of one of these articles, incredible to know that the global winds and jetstreams have actually been modelled for a whole range of speeds for the Earth's rotation!

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Having read through the articles referred by Interitus it is, as I say, interesting indeed that some scientists have done GCM modelling of how the global winds might behave under different (slower) rates of the Earth's rotation.  My take though is that the higher-latitude (Ferrel) Westerlies in both hemispheres are likely to be much more sensitive to slower rates of the Earth's rotation than these models suggest for the following reasons:

1) A good amount of the "Need" for a sink for atmospheric westerly momentum in the global circulation is absorbed by high mountain ranges in the Northern Hemisphere that are exposed to the Circumpolar Vortex (winds at the height of Mount McKinley, more so for much of the Himalayas can be very strong).  This reduces the need for strong low-level Westerlies everywhere between 40 and 70N.  The Circumpolar Vortex is likely to become weaker (and meander more north to south) with slower rates of the Earth's rotation and it will (thus) be more likely to come into contact with both lower-latitude high-mountain ranges and those within the Arctic (i.e Greenland and parts of Alaska)- even though the Circumpolar Vortex is likely to shift polewards.  So mountain ranges will continue to act as a sink for much atmospheric Westerly momentum which means there will be significantly less for low-level mid and higher latitude westerlies.

The Southern Hemisphere has, of course few high mountain ranges, which implicitly explains the Roaring Forties and Furious Fifties to counteract the SE Trade Winds.  However, some of the Southern Andes do reach the very strong Westerlies of the Circumpolar Vortex as do some of the mountains on New Zealand's South Island.  If the Circumpolar Vortex shifts polewards with a slower rotation rate of the Earth these upper-winds would also intercept the the top end of Transantarctic Mountains and with the SE Trades becoming more SSE there will be less atmospheric westerly momentum generated elsewhere; the higher-latitude Westerlies of the Southern Hemisphere would weaken substantially.

2) With days and nights not much longer than those at present in the tropics diurnal wind-patterns (sea and land breezes) which can come in from the west as well as east will dilute the overall "easterliness" of the NE and SE Trade winds, stronger convection currents by day in the tropics (but not right at the equator) will (through stronger downdraughts) cause some of the upper Westerlies equatorwards of the subtropical Jetstream to connect with the surface.  This is most likely to happen in upland tropical plateaus (like the Peru/Bolivian Altiplano) in spring and summer where the Sun would be strong and in the sky for a long time, such processes would further dilute the "Need" for higher-latitude low-level Westerlies to counterbalance tropical and subtropical winds.

The higher-latitude Westerlies are actually quite fragile, just a little weakening in the strength of upper Westerlies (or indeed weakening of the Need for a sink for Westerly atmospheric momentum) can play out in dramatic fashion.  Even with the Earth rotating once on its axis in 23 hours, 56 minutes (a 24 hour day is only such because the Earth's rotation does so against our planet's orbit around the Sun) small interruptions such as Sudden Stratospheric Warmings over the Arctic in winter or increases in snow and ice-cover over northern continents seems suffice to throw the higher-latitude Westerlies off course and then locations at the western margins of continents in middle latitudes get northerly or easterly winds instead.  If the Earth's rotation is just a bit slower the frequency of such blocking situations would escalate quickly as the need for a sink for higher latitude Westerlies is reduced.

3) Frigid surfaces covered in snow and ice with relatively warmer air aloft do not, under any circumstances, offer good breeding grounds for depressions to form, quite the opposite infact.  So I do not think the Ferrel Westerlies and depressions polewards of them would simply retreat to the Polar Regions.  They would get pushed north, up to a point but then the Jetstream (and subtropical Jetstream) is likely to meander because the Tradeswill be less able to impart Westerly momentum to the atmospheric global circulation, so the upper Westerlies will be weaker.  The need for an outlet is likely to come from strong westerlies spawned by small depressions associated with upper troughs, these will be about 60 to 70N and very limited in longitudinal extent.

Another point with these articles is the suggestion that higher latitudes will be warm because the upper airflow from the tropics will be more direct.  At lower levels however, a much greater preponderance of anticyclones with dry clear skies dominating higher latitudes means much more intense longwave radiative heat loss in winter which must largely counteract this effect at the highest latitudes; for mid-latitudes the predominance of surface winds from high-latitudes (rather than from the southwest) would be a cooling effect which in winter would be exacerbated by clear dry skies (due high-pressure to the north) causing strong net-radiative heat loss. In summer sunny conditions would have a warming effect that could more than counteract cool winds from high latitudes.       

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I have read both the articles referred to above and I agree with the general findings with regard to the temperature profile of the upper atmosphere and charges to precipitation with a slower rotating Earth. If the Hadley Cells extend to high latitudes then upper air can flow much more easily from above the ITCZ to Arctic latitudes. This will clearly make upper air at higher latitudes warmer. It would also inhibit convection suffice to cause rain or snow anywhere on the Earth outside the ITCZ. 

What I much would dispute is that it would actually make most middle and higher latitudes warmer because the clear skies and dry thinner troposphere caused by the Hadley Cells extending well north (and south) means strong net radiation cooling near the surface from autumn through spring: This would make low level air much colder in winter, particularly given prevailing winds would be from the Arctic.  In summer very long sunny day's and subsidence of air originally of tropical origin would mean hot weather inland but clear longer nights would be colder. The Greenland and Antarctic ice sheets would slowly shrink away to nothing without snowfall (this would only happen with day-lengths of 100 hours plus);without ice covering the land these locations would get much warmer as the land absorbs the Sun's heat and atmospheric subsidence brings down air of tropical origin. In winter clear skies would still mean very cold indeed.

In low latitudes the direct advection of air from the Arctic and Antarctic would be a cooling influence but days would still get very hot with long days with high-elevation sunshine. The theses referred to above do make this point. Long nights with a thinner troposphere and clear skies would drop close to freezing point even at the Equator. 

It is my take that halving the Earth's rotation would lead to a cooler but drier climate almost everywhere, even if the absence of snow at high latitudes means ice-sheets disintegrate and sea levels rise. Some low lying lands might be flooded by rising seas but everywhere else would be largely dry and sunny (except along the ITCZ). 

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On 28/01/2016 at 9:19 PM, stewfox said:

I would love the idea of 2 year orbit of sun (current distance) longer winters /summers.

 

 

This means the Earth in its orbit would not move fast enough to prevent it spiralling in towards the Sun- with catastrophic consequences for life on Earth.  However, if Earth orbited at the distance of Mars (not close enough to collide with Mars though) we could have a two-year orbit as measured by current year durations: 365 48 hour-days, the Solar Constant more than halved and little influence of Ferrel Westerlies in mid-latitudes. The oceans would freeze and reflect away 80% of the weaker Sun's heat and Britain would have persistent north-NE winds from the Arctic with temperatures below -140C in winter, -100C on long summer nights and still far below freezing through the long long summer days with weak convection and a rare front perhaps (associated with a rare depression only likely to occur near 70N) providing light snowfalls occasionally.

Wouldn't such weather be exciting!!!

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Are we assuming that the mountain ridges would be in the same positions that we see them today? Or in new positions based on projected movement of tectonic plates in the distant future?

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13 hours ago, iapennell said:

This means the Earth in its orbit would not move fast enough to prevent it spiralling in towards the Sun- with catastrophic consequences for life on Earth.  However, if Earth orbited at the distance of Mars (not close enough to collide with Mars though) we could have a two-year orbit as measured by current year durations: 365 48 hour-days, the Solar Constant more than halved and little influence of Ferrel Westerlies in mid-latitudes. The oceans would freeze and reflect away 80% of the weaker Sun's heat and Britain would have persistent north-NE winds from the Arctic with temperatures below -140C in winter, -100C on long summer nights and still far below freezing through the long long summer days with weak convection and a rare front perhaps (associated with a rare depression only likely to occur near 70N) providing light snowfalls occasionally.

Wouldn't such weather be exciting!!!

I appreciate the dynamics would not make the idea workable

i read somehwere years ago if the Earth was suddenly to 'stop' the energy released would melt the Earths crust to 15 miles

ps I wonder how long it would take the ocean to freeze  :)

 

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Always pondered how our climate would be if the earth was simply spinning the other direction.

Would we have sea ice in winter? Then  sit watching the models in hope that  the mild Westerly in FI verifies.

How hot and thundery would the summer be with the flow off the continent?

 

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4 hours ago, 80sWeather said:

Always pondered how our climate would be if the earth was simply spinning the other direction.

Would we have sea ice in winter? Then  sit watching the models in hope that  the mild Westerly in FI verifies.

How hot and thundery would the summer be with the flow off the continent?

 

That's the most sensible 'option' if we could choose our planet to behave differently to achieve cracking winters as this is the only one that's actually sustainable and wouldn't do much damage, forgetting the actual process of reversal of course as that would create problems, I would like to hear from knowledgeable people on this but assuming everything else in the solar system was mirrored, surely the fact that we are roughly the same latitude as Siberia (and higher than New York) then we could get very good winters, would it actually be the same effect as a reversal of zonal winds?

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4 hours ago, 80sWeather said:

Always pondered how our climate would be if the earth was simply spinning the other direction.

Would we have sea ice in winter? Then  sit watching the models in hope that  the mild Westerly in FI verifies.

How hot and thundery would the summer be with the flow off the continent?

 

The latitudes of Britain would have prevailing east or SE winds (NE winds would also be common in winter caused by air spilling outwards and anticlockwise from high-pressure over Russia)  driven by a Circumpolar Vortex of easterlies: Our climate would certainly be much more continental in nature and colder- a bit like eastern Canada or Kamchatka in the far east of Russia today. Eastern Canada would be mild with prevailing winter east or SE winds blowing off the North Atlantic in this scenario!! 

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