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

[Frost HoIIow]

I enjoy reading your posts Ian. You certainly know your stuff.

[stewfox]

5 hours ago, iapennell said:

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!! 

Do you think there would be an effect on the gulf stream ?

[iapennell]

On 07/02/2016 at 8:33 PM, stewfox said:

Do you think there would be an effect on the gulf stream ?

If the Earth rotated in the opposite direction there would certainly be a big effect on the North Atlantic Drift (to give it its correct name in the latitudes of the northern North Atlantic). The prevailing easterly winds (north-east in winter) would prevent warm waters reaching towards the UK. On the contrary, with the Earth rotating from east to west the Ekman Spiral effect would cause westward -driven ocean currents to angle towards the south (more so at depth). It means that the ocean currents affecting Britain would come down through the Norwegian Sea Gap from the Central Arctic ; this means pack-ice would surround the British Isles for most of the year!!

With the Earth rotating at just half it's current speed the absence of Westerlies south of about 50N means there is unlikely to be any Gulf Stream or North Atlantic Drift as such. Cold Arctic winds will (as I have pointed out above) occur often over most of the North Atlantic whilst bitter cold north-easterly winds off Russia would be common in winter off the NW European Sea-board. The Ekman Spiral effect will be weak so prevailing north-easterly winds around Britain for much of the winter with northerlies much of the rest of the year means an icy pack-ice filled current from the Arctic is likely to flow south through the Norwegian Sea Gap and around Britain. Again this would result in coastal waters freezing up several months each year with the result being frigid air reaches Britain from the Arctic or from Russia without any amelioration whatsoever. This is why very long clear January nights would frequently dip to -50C over much of Britain!! 

[iapennell]

Since slowing the Earth down is beyond the wildest-imagineable technological abilities of mankind (and as some rightly pointed out this would result in the oceans piling up at higher latitudes inundating countries such as Britain if it was done on any timescale short of a million years!); so the nearest we could get to having the weather normally associated with it would be for millions of large 2 km tall artificial "fir-trees" placed atop the Rockies of North America and the northern Himalayas to absorb the strength of strong jet-streams above these latitudes and in so doing absorb the "need" for higher-latitude Westerlies at low levels to counterbalance subtropical and tropical easterlies.

This might be a way of stopping global warming- by keeping mid and high-latitudes cold for snow and ice to persist for longer each year, though the resultant big shortage of rain in all areas outside the deep tropics will make drought a major threat to the ability of mankind to feed itself (as would frequent and severe spring and autumn frosts anywhere north of about 35N). 

[feb1991blizzard]

What about having a rocket launcher propel huge nuclear devices into the stratosphere over the North pole programmed to explode just at the right altitude, thus warming the trop up through the stratosphere, would this not automatically reverse the zonal winds?

[iapennell]

9 minutes ago, feb1991blizzard said:

What about having a rocket launcher propel huge nuclear devices into the stratosphere over the North pole programmed to explode just at the right altitude, thus warming the trop up through the stratosphere, would this not automatically reverse the zonal winds?

@feb1991blizzard If this could be done it would be a large man-made Sudden Stratospheric Warming over the Central Arctic; if it was big enough it would result in a reversal of the Polar Night Westerlies (if this was done autumn-winter) which would interact with the atmospheric circulation over the wider region to cause east-NE winds with the Westerlies displaced into lower latitudes for a time.  There would be a couple of weeks of much colder east or NE winds in Britain before the Arctic stratosphere cooled again and the south-west winds returned to Briain; it would not be a permanent fix.  But if this operation could be repeated it could have the makings of a record severe winter not just in Britain but also across Europe and the northern USA; but then, of course, there would be the problem of radiation fallout from frequent nuclear explosions in the Arctic stratosphere........Maybe this is not such a good idea!!  Then again, the logistics of getting millions of huge artificial fir trees to (and secured in place) atop the Rockies and Himalayas in far-below-freezing winds could be unworkable.

[feb1991blizzard]

3 minutes ago, iapennell said:

@feb1991blizzard If this could be done it would be a large man-made Sudden Stratospheric Warming over the Central Arctic; if it was big enough it would result in a reversal of the Polar Night Westerlies (if this was done autumn-winter) which would interact with the atmospheric circulation over the wider region to cause east-NE winds with the Westerlies displaced into lower latitudes for a time.  There would be a couple of weeks of much colder east or NE winds in Britain before the Arctic stratosphere cooled again and the south-west winds returned to Briain; it would not be a permanent fix.  But if this operation could be repeated it could have the makings of a record severe winter not just in Britain but also across Europe and the northern USA; but then, of course, there would be the problem of radiation fallout from frequent nuclear explosions in the Arctic stratosphere........Maybe this is not such a good idea!!  Then again, the logistics of getting millions of huge artificial fir trees to (and secured in place) atop the Rockies and Himalayas in far-below-freezing winds could be unworkable.

Ha yes, I did think about the fact that the Arctic high would by deliver what we had just chucked into the Arctic back (radiation)!!