24 replies to this topic

[Verglas]

a question posed on BBC radio2 yesterday was "what effect would there be if the world rotated the opposite direction ?"

the pundit who replied was very vague really, he said about the sun rising in the west etc, but no mention whatsoever of the weather.

I think the effects on the weather would be a major climate changing factor, either turning us into an arctic region or a desert depending what happened in the atlantic which seems to be the major influence on our climate.

What do you think would happen to UK weather ?

[Yozzer]

Verglas, on 20 January 2011 - 10:20 , said:

a question posed on BBC radio2 yesterday was "what effect would there be if the world rotated the opposite direction ?"

the pundit who replied was very vague really, he said about the sun rising in the west etc, but no mention whatsoever of the weather.

I think the effects on the weather would be a major climate changing factor, either turning us into an arctic region or a desert depending what happened in the atlantic which seems to be the major influence on our climate.

What do you think would happen to UK weather ?

Hi Verglas. Interesting hypothesis. The coriolis effect would be reversed. therefore in the northern hemisphere movement of air around low pressure would be clockwise, and around high pressure anti-clockwise. In addition weather systems would have a tendency to move east to west. The net result would be a climate similar to the east coast of the eurasian or north american landmasses at the same latitude. What the effect would be on ocean circulation I'm not sure. Probably a similar effect.
Another effect might well be changes in the Earth's magnetic field.

Edited by Yozzer, 20 January 2011 - 10:34 .

[ajpoolshark]

Backtrack, on 20 January 2011 - 10:32 , said:

Nothing would change weather wise.

The winds or oceans aren't switching around, so nothing would be different.

Tosh!.... but they would...totally, due to the coriolis effect,,,Weather systems in the northern hemisphere would push east to west, having a profound impact on climate, and indeed ocean currents...I would hazard a guess that here in the UK, we would have a climate similar to Newfoundland, and who knows?...hurricanes forming off the north African coasting drifting NE on the reversed trade winds into Biscay???...fascinating stuff!

[Essan]

The main difference would be that weather systems would track east to west. The NAD would flow from the coast of Africa across to Newfoundland. The Canadian Maritimes would enjoy a much milder climate whilst we in Britain would be under a stronger continental influence experiencing warmer summers but much colder winter, often with ice around our shores. The Hudson river in America would no longer freeze in winter, but the Thames would.

In summer, places like Morroco, Portugal and Spain would often experience hurricanes, with a few tracking north to Britain. The Carribean would largely be hurricane free.

Basically: the prevalent climate either side of the Atlantic would be reversed. Though in reality there would be further complications due to the positioning of mountain ranges etc - an interesting idea should anyone ever get hold of a climate model to play with for a few months!

[Backtrack]

ajpoolshark, on 20 January 2011 - 10:58 , said:

Tosh!.... but they would...totally, due to the coriolis effect,,,Weather systems in the northern hemisphere would push east to west, having a profound impact on climate, and indeed ocean currents...I would hazard a guess that here in the UK, we would have a climate similar to Newfoundland, and who knows?...hurricanes forming off the north African coasting drifting NE on the reversed trade winds into Biscay???...fascinating stuff!

Sorry for trying.......

[ajpoolshark]

Backtrack, on 20 January 2011 - 12:38 , said:

Sorry for trying.......

I beg your pardon?...non comprendez pas

[butler_son]

ajpoolshark, on 20 January 2011 - 13:09 , said:

I beg your pardon?...non comprendez pas

That should read "je ne comprends pas". Assuming you're trying to speak French.

On topic though - would our climate be more like Newfoundland or Hokkaido? My tutor at uni did his post doc in St Johns NF, and said the climate was horrific - that most days were foggy or cloudy and that you got about 14 sunny days a year. Probably an exaggeration, but he was unimpressed (he is Bulgarian). Whereas Hokkaido...well, the Sapporo snow festival should tell you everything you need to know about that locality...

Edited by butler_son, 20 January 2011 - 13:21 .

[ajpoolshark]

butler_son, on 20 January 2011 - 13:18 , said:

That should read "je ne comprends pas". Assuming you're trying to speak French.

B_S....perhaps an more 'on-topic' response to this thread would be more appropriate to this thread......"Serious discussion' thread shouldn't contain idle banter....If you have issues with any post, I suggest you pm me, or contact another member of the moderating team......cheers

I see you have now edited your post

btw, I don't speak french, just spell it badly...ahem!

Edited by ajpoolshark, 20 January 2011 - 13:38 .

[Nick L]

As mentioned above, the change in the coriolis effect would cause very noticeable changes - what those changes would be though would be a very interesting subject!

Although I am trying not to think about what would happen as I have enough trouble as it is on my course trying to envisage the effects of the coriolis effect in its current direction

Edited by Nick L, 20 January 2011 - 13:39 .

[butler_son]

The contenders:

http://en.wikipedia....akhalin#Climate

A bit further south than our lattitude http://en.wikipedia....Sapporo#Climate

http://en.wikipedia....nd_Labrador#Climate - contains phrase: "Of major Canadian cities, St. John's is the foggiest (124 days), snowiest (359 cm (141 in)), wettest (1,514 mm (59.6 in)), windiest (24.3 km/h (15.1 mph) average speed), and cloudiest (1,497 hours of sunshine)."

http://en.wikipedia....r_Brook#Climate

Possibly a bit too far inland: http://en.wikipedia....ose_Bay#Climate

Sakhalin looks most likely to me, truth be told. But the snow lovers on here would love the Earth to spin the other way if these would be the climate analogues!

Also, imagine "nor'westers". A low pressure system that slides up Spain and France, dragging cold air in off its eastern flank and huge precipitation.

Edited by butler_son, 20 January 2011 - 14:05 .

[ajpoolshark]

I'm also wondering on the possible effects to sea-levels, a rise or fall perhaps?....an increase in severe thunderstorms during the spring and summer months, perhaps a new tornado alley forming through France/Germany extending into the British Iles, as in spring we could have dry Easterly/NEasterlies colliding with warm moisture laden air pulled north westwards from the increasingly warmer waters of the Mediterranean Sea??.....As B_S mentioned, huge winter storms dragged up the West European coastline......Major flooding along Southern UK coasts during the new Hurricane season? ...........so how can we make all this happen?

With the authors permission, I'd like this thread to be moved to a more appropriate part of the forum to increase thread visibility

Edited by ajpoolshark, 20 January 2011 - 14:19 .

[Thundery wintry showers]

Philip Eden explored this in brief in his 1995 book "Weatherwise" and pointed out that the North Sea may make a significant difference, particularly in eastern parts of Britain. SSTs would be much lower and so we would most likely see plenty of low cloud and drizzle in the eastern half of the country during the summer months, with sunshine confined to sheltered western areas.

We'd probably get some pretty dramatic "thundery wintry showers" setups in October and November with the continent cooling off and those cold airmasses heading across the comparitively warm North Sea. However, chances are that much of the North Sea would freeze over during the winter months leading to a good deal of dry and extremely cold weather with plenty of freezing fog, and the traditional SW-NE split in winter snowfall would be reversed with the north Atlantic and English Channel generating heavy snowfalls chiefly for the west and south.

I can imagine spring being a particularly dismal time of year in the east- anyone remember March 1996? The early part of spring would see the North Sea unfreeze as the continent warms up so we'd end up with a transition from severely cold, dry weather to less cold with lots of low cloud and drizzle.

[butler_son]

ajpoolshark, on 20 January 2011 - 14:17 , said:

I'm also wondering on the possible effects to sea-levels, a rise or fall perhaps?....an increase in severe thunderstorms during the spring and summer months, perhaps a new tornado alley forming through France/Germany extending into the British Iles, as in spring we could have dry Easterly/NEasterlies colliding with warm moisture laden air pulled north westwards from the increasingly warmer waters of the Mediterranean Sea??.....As B_S mentioned, huge winter storms dragged up the West European coastline......Major flooding along Southern UK coasts during the new Hurricane season? ...........so how can we make all this happen?

With the authors permission, I'd like this thread to be moved to a more appropriate part of the forum to increase thread visibility

Hmmm, not entirely convinced about a change in tornadoes or hurricanes, we'd still be getting extratropical remnants much like Newfoundland does, it's Nova Scotia further south in the Maritimes that has had a direct hit by a storm with tropical characteristics (Hurricane Juan). And Hurricane Faith hit the Faeroe Islands as a hurricane (with tropical characteristics) if I remember correctly. I don't think the Med would be any warmer than it is currently to be fair.

[ajpoolshark]

butler_son, on 20 January 2011 - 15:22 , said:

Hmmm, not entirely convinced about a change in tornadoes or hurricanes, we'd still be getting extratropical remnants much like Newfoundland does, it's Nova Scotia further south in the Maritimes that has had a direct hit by a storm with tropical characteristics (Hurricane Juan). And Hurricane Faith hit the Faeroe Islands as a hurricane (with tropical characteristics) if I remember correctly. I don't think the Med would be any warmer than it is currently to be fair.

The North Equitorial current would be mirror imaged I guess, if so, it would, over time, flood the north east atlantic & med basin with warmer equitorial waters, enhancing the 'fuel' available for hurricanes IMO....The gulf stream would be renamed the Azores stream, I could imagine countries like Morroco & Spain being slammed during hurricane season, parts of the UK being hit by decaying CAT 2 or CAT 1 hurricanes, with storms on the more southern 'Morrocon' track passing through the Straights of Gilbraltor to re-invigorate in the Western Med....a knock-on effect of this water warming would be an increase in contrasting air-masses during the spring months, moist South Westerlies, colliding with cold, dry north easterlies in situ over northen Europe. This IMO would be the engine to generate the Severe storm/Tornado machine through France/Germany/Benelux and into the SE of the UK......It is, of course, total guess work......I, for one, would love some of the more experienced NW climate & model watchers to join this discussion & give us their expert opinions!

[butler_son]

ajpoolshark, on 20 January 2011 - 16:03 , said:

The North Equitorial current would be mirror imaged I guess, if so, it would, over time, flood the north east atlantic & med basin with warmer equitorial waters, enhancing the 'fuel' available for hurricanes IMO....The gulf stream would be renamed the Azores stream, I could imagine countries like Morroco & Spain being slammed during hurricane season, parts of the UK being hit by decaying CAT 2 or CAT 1 hurricanes, with storms on the more southern 'Morrocon' track passing through the Straights of Gilbraltor to re-invigorate in the Western Med....a knock-on effect of this water warming would be an increase in contrasting air-masses during the spring months, moist South Westerlies, colliding with cold, dry north easterlies in situ over northen Europe. This IMO would be the engine to generate the Severe storm/Tornado machine through France/Germany/Benelux and into the SE of the UK......It is, of course, total guess work......I, for one, would love some of the more experienced NW climate & model watchers to join this discussion & give us their expert opinions!

See, I disagree - I think the Med is warmed in part by the North Atlantic current as it is, any reversal (warm waters from the Azores to the Canadian Maritimes) would cut off this feed of warmer water. I'd compare the climate of Barcelona with that of Providence, Rhode Island as two arbitrary places to see this. Av temp for the year in Barcelona (41.23N) is 15.6C, which is the same as the average high for the year in Providence (41.49N). Average high temp in Barcelona is 20.0, a big step up from Providence. Providence is coastal, though unlike Barcelona, is not warmed by the warm waters of the Med or the North Atlantic current. Thus January's average low is -6.5 in Providence, yet the lowest temperature ever recorded in Barcelona is -6.7. Yet it's Providence that is exposed to hurricanes (although very very rarely), and I don't think one has ever hit Lisbon. Which goes back to me saying that I don't believe Spain will get hit all too often (Morocco and Western Sahara, the Southern parts of the Iberian Peninsula, the Canaries, Azores and Madeira will though, ironically the Cape Verde islands would too), and Britain would get the cast offs a la St John's. Like I say, even Nova Scotia (at about 45N) has only really been hit once, so it's doubtful that Britain at 50N (well, here is 50N) would be hit more than they are at present.

I guess what I'm trying to say is just because the Med is warm now doesn't mean it will stay that way if the Earth spun the other way - you may find that the Med temps drop, and would thus be unable to support tropical systems (which require temps hotter than the Med at present).

And I realise Providence is on the Atlantic coast and Barcelona isn't, but I expect it's similar in A Coruna, or comparing Lisbon with Washington.

Going back to specifically Britain in our hypothetical situation, looking at the climates of St John's and Sakhalin, they are both extremely foggy and cold. I would imagine that the climate in Britain would be economically disastrous, given the agriculture (which would have a much shorter growing season than at present) and shipping in the English Channel (the importance of the Channel as a shipping lane would diminish significantly if it iced over). Is it any wonder that the biggest settlement in Labrador is less than 8,000 in population (half that of Verwood) and St. John's NF is only as big as Bournemouth population wise?

And again, not overly sold on tornadoes for here - would need to be much further south. I'd say the Balkans if they weren't so mountainous...

(Edited because of my poor Portuguese geography.)

Edited by butler_son, 20 January 2011 - 16:48 .

[ajpoolshark]

butler_son, on 20 January 2011 - 16:33 , said:

See, I disagree - I think the Med is warmed in part by the North Atlantic current as it is, any reversal (warm waters from the Azores to the Canadian Maritimes) would cut off this feed of warmer water. I'd compare the climate of Barcelona with that of Providence, Rhode Island as two arbitrary places to see this. Av temp for the year in Barcelona (41.23N) is 15.6C, which is the same as the average high for the year in Providence (41.49N). Average high temp in Barcelona is 20.0, a big step up from Providence. Providence is coastal, though unlike Barcelona, is not warmed by the warm waters of the Med or the North Atlantic current. Thus January's average low is -6.5 in Providence, yet the lowest temperature ever recorded in Barcelona is -6.7. Yet it's Providence that is exposed to hurricanes (although very very rarely), and I don't think one has ever hit Lisbon. Which goes back to me saying that I don't believe Spain will get hit all too often (Morocco and Western Sahara, the Canaries, Azores and Madeira will though), and Britain would get the cast offs a la St John's. Like I say, even Nova Scotia (at about 45N) has only really been hit once, so it's doubtful that Britain at 50N (well, here is 50N) would be hit more than they are at present.

I guess what I'm trying to say is just because the Med is warm now doesn't mean it will stay that way if the Earth spun the other way - you may find that the Med temps drop, and would thus be unable to support tropical systems (which require temps hotter than the Med at present).

And I realise Providence is on the Atlantic coast and Barcelona isn't, but I expect it's similar in A Coruna, or comparing Lisbon with Washington.

Going back to specifically Britain in our hypothetical situation, looking at the climates of St John's and Sakhalin, they are both extremely foggy and cold. I would imagine that the climate in Britain would be economically disastrous, given the agriculture (which would have a much shorter growing season than at present) and shipping in the English Channel (the importance of the Channel as a shipping lane would diminish significantly if it iced over). Is it any wonder that the biggest settlement in Labrador is less than 8,000 in population (half that of Verwood) and St. John's NF is only as big as Bournemouth population wise?

And again, not overly sold on tornadoes for here - would need to be much further south. I'd say the Balkans if they weren't so mountainous...

(Edited because of my poor Portuguese geography.)

It's possible that your example may be flawed...Providence falls under the influence of the cold labrador current, as the Gulf Stream is forced out into the mid-atlantic as it passes the Cape Hatteras area, so cannot be used as a climate comparison to Barcelona.....The current that feeds the med is the returning NAD which is a cooler current where it meets the entrance to the Med, where as with a rotation reversal it's the opposite, in theory..ie the north equatorial current would feed the med, which is already warm...As mentioned earlier, it's a result of the Coriolis effect, thus warmer waters in the equitorial atlantic would flood North/North Eastwards along the continental boundaries...............

....So there you have it, we'll have to agree to disagree....yet again on a thread!....lol

[butler_son]

ajpoolshark, on 20 January 2011 - 17:12 , said:

It's possible that your example may be flawed...Providence falls under the influence of the cold labrador current, as the Gulf Stream is forced out into the mid-atlantic as it passes the Cape Hatteras area, so cannot be used as a climate comparison to Barcelona.....The current that feeds the med is the returning NAD which is a cooler current where it meets the entrance to the Med, where as with a rotation reversal it's the opposite, in theory..ie the north equatorial current would feed the med, which is already warm...As mentioned earlier, it's a result of the Coriolis effect, thus warmer waters in the equitorial atlantic would flood North/North Eastwards along the continental boundaries...............

....So there you have it, we'll have to agree to disagree....yet again on a thread!....lol

Oh no, not again AJ! Did I ever tell you I don't like Theakston's Old Peculier either?

It's a similar story (though not by much) south of Cape Hatteras: http://en.wikipedia....arolina#Climate - cf http://en.wikipedia....i/Cadiz#Climate (Cadiz manages to be warmer, even though it's 2 degrees futher north).

Jan mean temp in Cadiz: 10.7; Jan mean temp in Wilmington NC: 7.8
Jul mean temp in Cadiz: 25.5; Jul mean temp in Wilmington NC: 27.3

So I guess you could argue swings and roundabouts, but there is still 2 degrees of lattitude difference. And I can't find data for Tangier.

And who's to say that there wouldn't be a cold current running down the coast of Portugal?

Edited by butler_son, 20 January 2011 - 18:04 .

[ajpoolshark]

butler_son, on 20 January 2011 - 17:56 , said:

Oh no, not again AJ! Did I ever tell you I don't like Theakston's Old Peculier either?

It's a similar story (though not by much) south of Cape Hatteras: http://en.wikipedia....arolina#Climate - cf http://en.wikipedia....i/Cadiz#Climate (Cadiz manages to be warmer, even though it's 2 degrees futher north).

Jan mean temp in Cadiz: 10.7; Jan mean temp in Wilmington NC: 7.8
Jul mean temp in Cadiz: 25.5; Jul mean temp in Wilmington NC: 27.3

So I guess you could argue swings and roundabouts, but there is still 2 degrees of lattitude difference. And I can't find data for Tangier.

And who's to say that there wouldn't be a cold current running down the coast of Portugal?

1) yes, you did....oh well!

2) and who's to say the moon may end being made out of cheese because of the rotation reversal? lol

The bottom line is that in this hypothetical situation, any climatical scenario could play out........one thing though, in this thread, it's pointless comparing climatical data for two points on opposite sides of the atlantic just based on latitude....The Afro-Eurasian landmass is far larger than the Continental American landmass, this in itself would cause huge climatical differences due to a reversal, just swapping climate events from one side of the atlantic to the other just doesn't cut the mustard IMO.......

....another interesting scenario would be on what role the Bay of Biscay play in this hypothesis?.......I can forsee a cold current moving north to south off the west coast of the british Isles, would that cause an 'eddy' effect in Biscay as it interacts with tropical water drifting northwards, and if so, what effect would this have on the UK's weather, a breeding ground for some kind of 'superstorm'...the mind boggles just thinking of such possible events


Ah, just seen your map, it echoes my point about the cold water eddy, plus the coriolis effect would cause the north equitorial current to drift up pass portugal

Edited by ajpoolshark, 20 January 2011 - 18:16 .

[butler_son]

ajpoolshark, on 20 January 2011 - 18:13 , said:

1) yes, you did....oh well!

2) and who's to say the moon may end being made out of cheese because of the rotation reversal? lol

The bottom line is that in this hypothetical situation, any climatical scenario could play out........one thing though, in this thread, it's pointless comparing climatical data for two points on opposite sides of the atlantic just based on latitude....The Afro-Eurasian landmass is far larger than the Continental American landmass, this in itself would cause huge climatical differences due to a reversal, just swapping climate events from one side of the atlantic to the other just doesn't cut the mustard IMO.......

....another interesting scenario would be on what role the Bay of Biscay play in this hypothesis?.......I can forsee a cold current moving north to south off the west coast of the british Isles, would that cause an 'eddy' effect in Biscay as it interacts with tropical water drifting northwards, and if so, what effect would this have on the UK's weather, a breeding ground for some kind of 'superstorm'...the mind boggles just thinking of such possible events

Yeah, there is no right or wrong answer, I'm just trying to find analogues. Also Europe's a funny shape and the east coast of the US, well, isn't. Who knows if the hypothetical current would reach the Med? As for Biscay, I think I'm with you there, some serious cold core lows could form (hello nor'westers). Wouldn't want to live in Brittany by that point...

[ajpoolshark]

agreed!......I would like to thank the author for posting this thread, it's already led to some fascinating discussion, just to echo an earlier comment, it would be cool for some of the experienced climate/model watchers to join the discussion to add their input as well