jimi
Well-Known Member
As Polar ice melts, presumably the ice melt will enter the ocean currents thus cooling sea water in temmperate climates? Could this account for our recent rubbish summers and, good springs and autumns?
Global Warming, Jet Streams and Weather
- Thread starter jimi
- Start date
bilbobaggins
N/A
You could very well be right.
Here's some interesting detail on the ThermoHalineCirculation, enough to keep a certain 'Webbie' engaged for hours....
Here's some interesting detail on the ThermoHalineCirculation, enough to keep a certain 'Webbie' engaged for hours....
I believe it's actually to do with the fact that fresh water is lighter than sea water or visa versa effecting convection.It's that that alters the worlds currents & therefore climate.
Twister_Ken
Well-Known Member
I blame Gordon Brown.
Not exactly got a sunny disposition, has he?
Not exactly got a sunny disposition, has he?
webcraft
Well-Known Member
I don't think anyone really knows for sure what feedback loops may be lurking in the wings Jimi, but experimenting on our own planet is a bl00dy stupid way of finding out.
The North Pole will make an interesting cruising destination though.
- W
jimi
Well-Known Member
From Bilbo's link
"The North Atlantic loop of the THC is controlled by the sinking of dense (cold and salty) water at high latitudes. The density of seawater is a result of both temperature and salinity (salty water is denser than fresh water, and cold water denser than warm water). Although the Gulf Stream water is saltier than the deep water below, it is much warmer, so its density is lower, and it remains on the surface. On its journey north, the water releases heat to the atmosphere, and cools gradually, until it is cold enough for its density to match that of the deep layer. Sinking can begin.
At this stage the surface water is still warmer than the deep water, but it also saltier, so its density matches that of the deeper water, allowing the two layers to mix. Should the surface water freshen for some reasons, it would have to cool further before it can sink. Sufficient freshwater input might reduce salinity to the extent that the surface water could not possibly sink, even at sub-zero temperatures.
Paradoxically global warming could create precisely this effect. Increased rainfall, melting of sea ice, glaciers and the Greenland ice sheet are all possible consequences of higher temperatures, and could reduce North Atlantic surface salinity sufficiently to slow down or even stop the formation of deep water. If this happens, the THC may shut down. Once stopped, the heat conveyor may take time to recover, and the consequences would be a cooling of northwest Europe. "
Yikes .. if we are seeing the start of this, then that is not good news cos there is an awfie lot of ice to melt/melting on Greenland
"The North Atlantic loop of the THC is controlled by the sinking of dense (cold and salty) water at high latitudes. The density of seawater is a result of both temperature and salinity (salty water is denser than fresh water, and cold water denser than warm water). Although the Gulf Stream water is saltier than the deep water below, it is much warmer, so its density is lower, and it remains on the surface. On its journey north, the water releases heat to the atmosphere, and cools gradually, until it is cold enough for its density to match that of the deep layer. Sinking can begin.
At this stage the surface water is still warmer than the deep water, but it also saltier, so its density matches that of the deeper water, allowing the two layers to mix. Should the surface water freshen for some reasons, it would have to cool further before it can sink. Sufficient freshwater input might reduce salinity to the extent that the surface water could not possibly sink, even at sub-zero temperatures.
Paradoxically global warming could create precisely this effect. Increased rainfall, melting of sea ice, glaciers and the Greenland ice sheet are all possible consequences of higher temperatures, and could reduce North Atlantic surface salinity sufficiently to slow down or even stop the formation of deep water. If this happens, the THC may shut down. Once stopped, the heat conveyor may take time to recover, and the consequences would be a cooling of northwest Europe. "
Yikes .. if we are seeing the start of this, then that is not good news cos there is an awfie lot of ice to melt/melting on Greenland
jason -and the arguenauts
Well-Known Member
what good springs and autumns? bring back hosepipe bans I say.
global warming was always forecast to make the UK wetter and windier, possibly even colder if the gulf stream vanished as some say it will.
just our luck isnt it. everywhere else gets warm and we get wet. And to make it worse when we had nice warm bits to go to as part of the empire we shipped in loads of people who didnt want to leave home and ultimately thanked us for nothing bu bu**ering off and going independant.
global warming was always forecast to make the UK wetter and windier, possibly even colder if the gulf stream vanished as some say it will.
just our luck isnt it. everywhere else gets warm and we get wet. And to make it worse when we had nice warm bits to go to as part of the empire we shipped in loads of people who didnt want to leave home and ultimately thanked us for nothing bu bu**ering off and going independant.
PeterGibbs
Well-Known Member
As nations we concern ourselves about the state of the atmosphere, but the sea, with its much greater density contains and distributes much more energy so its condition is much more critical to our survival.
Sea water around the UK has already risen appreciably in temperature, whatever the melting of the Alpine and Greenland glaciers; density declines with rising temperature and this will be a major cause of flooding in years to come - it's already happening.
PWG
Sea water around the UK has already risen appreciably in temperature, whatever the melting of the Alpine and Greenland glaciers; density declines with rising temperature and this will be a major cause of flooding in years to come - it's already happening.
PWG
pugwash
Well-Known Member
Don't think it's going to melt though...
See
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
The decline of Arctic sea ice year before last was caused by winds, not temperatures.
See
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
The decline of Arctic sea ice year before last was caused by winds, not temperatures.
LittleSister
Well-Known Member
Ah! But what caused the winds?
Beadle
Well-Known Member
I thought our rotten weather was the fault of the jet stream getting lost and wandering up the English Channel instead of going to Iceland where it belongs.
MarkJohnson12345
Well-Known Member
Are we sure that the 'Global Warming' is just not part of a long term cycle?
The glaciers have been retreating for a couple of a hundred years I think.
Whilst burning all those fossil fuels cannot help the situation, and may exacerbate the natural cycles, I think we cannot buck the natural cylcles.
But that no excuse not to try and reduce burning these valuable resourses (sp)
Get rid of cows, they exceed motor car pollution by many times. Drink beer instead!!!!
The glaciers have been retreating for a couple of a hundred years I think.
Whilst burning all those fossil fuels cannot help the situation, and may exacerbate the natural cycles, I think we cannot buck the natural cylcles.
But that no excuse not to try and reduce burning these valuable resourses (sp)
Get rid of cows, they exceed motor car pollution by many times. Drink beer instead!!!!