39 replies to this topic

[IanfromNewark]

Winter 2009 took us by surprise when NE winds blasted in at the end of January, and lasted three weeks.
Winter 2010 started around 20 December and lasted two months. Jan average in Newark, max 4.3C min 0.1C. Coldest night at -4.8C
This time it started by 26 November and 28th was a record cold min of -8.8C, and we have had much more snow already, more here than since 1979
I have watched several videos on Youtube suggesting the Gulf Stream is fizzling out. Is this not the scenario that we would expect

[Essan]

There is no evidence that the Gulf Stream (or rather the NAD) determines long term Northern Hemisphere synoptics. All it does is slightly warm the waters around our shores - so any cold air crossing them is very slightly milder when it gets here.

And we've had longer, colder, snowier winters within living memory that were not caused by the Gulf Stream stopping ...... so why assume that another such winter is caused by it?

Edit: and, never, ever, ever, take any notice of any video posted to youtube. It's to truth and fact what eating nothing but sugar cubes is to a good, balanced, diet

Edited by Essan, 04 December 2010 - 16:13 .

[IanfromNewark]

If all the Gulf Stream does is slightly warm the waters around us, why are we 20C or so warmer than Moscow in the winter...?

[su rui ke]

IanfromNewark, on 04 December 2010 - 22:39 , said:

If all the Gulf Stream does is slightly warm the waters around us, why are we 20C or so warmer than Moscow in the winter...?

We are warmer because we are on the eastern side of an ocean. Most of the air that reaches us has to cross that ocean and warms up by the time it gets here. That in itself is more important than the existence of the Gulf Stream - the Gulf Stream makes the water slightly warmer than it would otherwise have been but it is not the most important factor affecting our winters. Remember the Gulf Stream also passes close to Newfoundland!

[stewfox]

IanfromNewark, on 04 December 2010 - 15:24 , said:

Winter 2010 started around 20 December and lasted two months.

No winter 2010 started December 1st , the gulf stream is fine as it was in 1979

[john pike]

http://www.bbc.co.uk...lf_stream.shtml
should help
http://geography.abo.../gulfstream.htm
so should this

[ElectricSnowStorm]

I have read a book called 'frozen Britain' its about last winters freeze, its not theory's, and false info, just facts and studies from top scientists. from the causes of last winter up to future ones, using studies of the solar activity and its effects on the jet stream and what the Gulf Stream is up to!
If you read that book then you would believe what is happening is possibly right, that we are getting severe cold winters and maybe a maunder minumim(solar)and causing an ice age in eastern America, N Europe and UK..

The Gulf Stream/NAD north atlantic drift-the part of the gulf stream that ends up in the north atlantic and warms the UK and parts of Europe (france,other..)warming up to 5c during winter. if it stops then we would lose 5c! so if it slows/weakens then may 1c? the milder south west winds move across the ocean(warmed by GS/NAD)then reach our shores as mild winds, if the ocean was colder then winds would cool..

[ElectricSnowStorm]

IanfromNewark good thread!
my thoughts below:
1- Weak GS/NAD-colder atlantic waters below surface.
2-Effects felt during winter with sea surface cooling, as solar heats up ocean surface during summer, ocean surface colder in winter with summer heat loss and no/little solar heating.
3-Ocean cold below surface rising to surface during summer, cooling ocean surface.
4-Solar minumum, less heating of oceans.
5-Colder oceans affecting our climate and weather.

[Iceberg]

Yep the Gulf stream/NAD is the thing that keeps us warmer than the western coast of N.America at the same latitude.

Re NAD weakening there are alot of studies that indicate that a very negative NAO can shift the NAD and GS further south, obviously once shifted further south it leads to a more southerly tracking jet. This can be positive reinforcement mechanism i.e a cold winter/summer leads to further colder winters and summers, until something is trigged to allow the GS/NAD to shift further north again. maybe a large ENSO/AMO/PDO shift or even a atmospheric event.

As is always the case these things are horrendously inter connected, personally I don't see any connection/correlation with solar and GS or NAO.

[Blitzen]

I don't understand why the apparent weakening of the NAD causes such a stir on here? Surely something is causing our current changes. Personally, I cannot remember, other than January 1984, when, as I am now, standing up to my hips in snow! Last year it was up to my knees. I don't think it is the ONLY reason for this change but I do think it should be considered along with many other observations that cannot and should not be dismissed; Low solar activity, higher volcanic activity, southerly tracking jet stream, extreme world wide weather events, are all part of a pattern and I believe interconnected. The scientists/climatologists definitely do NOT have a handle on this as there are too many conflicting opinions. All we can do is wait, observe and record. It may just be a blip who knows. I certainly am not over confident in dismissing it entirely.

http://www.helium.co...climate-changes

Edited by Blitzen, 05 December 2010 - 08:54 .

[Gray-Wolf]

I'd imagine that Moscow is augmented by an inner continental climate type with home grown deep cold blocking most warmer incursions (like the Arctic used to before we mucked it up?) whereas we're by fluid water....check the coastal temps this a.m. compared with those up hills/middle of the Island.

Where we to loose the N.A.D. we'd still need to freeze the seas around us to allow any 'continental cold' to live over us for the winter and looking at Baffin/Hudson Bay this may well be becoming a thing of the past.......

[Rustynailer]

Are there any similarity's with the Gulf stream's wandering tracks over the years and the strength of Channel Lows here in winter? Like, are the Lows stronger if the GS does X or weaker if it does Y?
It strikes me as an interesting thing to look at. Not just Channel Lows but perhaps the North Sea being a fraction warmer or colder, giving more or less snow in an Easterly, etc.
Russ

http://rads.tudelft....anim_7_long.gif 2003 to Nov 2010 video from these people http://rads.tudelft.nl/gulfstream/

Edited by Rustynailer, 05 December 2010 - 11:33 .

[paul tall]

Gray-Wolf, on 05 December 2010 - 10:49 , said:

I'd imagine that Moscow is augmented by an inner continental climate type with home grown deep cold blocking most warmer incursions (like the Arctic used to before we mucked it up?) whereas we're by fluid water....check the coastal temps this a.m. compared with those up hills/middle of the Island.

Where we to loose the N.A.D. we'd still need to freeze the seas around us to allow any 'continental cold' to live over us for the winter and looking at Baffin/Hudson Bay this may well be becoming a thing of the past.......

What about Baffin and Hudson Bay?

[Gray-Wolf]

Just check out current ice levels and then check out the recent research on Baffin temp profiles (how fast it's warming throughout the water column), and then check out historic re-freeze/thaw times for both areas.

[paul tall]

OK so Husdon Bay is having a bad day.

Realistically, what are we saying here? Are we saying that a late freeze has happened this year or are we saying it is happening year after year?

[bobbydog]

Gray-Wolf, on 05 December 2010 - 10:49 , said:

I'd imagine that Moscow is augmented by an inner continental climate type with home grown deep cold blocking most warmer incursions (like the Arctic used to before we mucked it up?) whereas we're by fluid water....check the coastal temps this a.m. compared with those up hills/middle of the Island.

Where we to loose the N.A.D. we'd still need to freeze the seas around us to allow any 'continental cold' to live over us for the winter and looking at Baffin/Hudson Bay this may well be becoming a thing of the past.......

i agree. we cant really compare ourselves to moscow due to the continental factor. having watched the NOAA charts over the past few months, it does appear that the NAD has weakened. not having access to previous years charts means we have nothing to compare it to, to see if this is a natural fluctuation or something more unusual. i dont see how it could stop completely as it is part of a worldwide system of currents - they couldnt just all stop! however it could possibly be diverted by other factors. a large driver of the surface current is the wind. the jetstream being further south could be one cause of the apparent weakening. i wonder if in the past, a weakened NAD has allowed sea ice to form more easily at the furthest limits of the current, thereby 'blocking its path' and causing a cycle which allows this process to accelerate, eventually contributing to 'ice-age' conditions

anyway, just my little theory, feel free to 'point and laugh' if you wish

[malby]

paul tall, on 05 December 2010 - 11:42 , said:

OK so Husdon Bay is having a bad day.

Realistically, what are we saying here? Are we saying that a late freeze has happened this year or are we saying it is happening year after year?

I think the poster is attempting to state that this is all down to AGW when, more probably, all that has happened is that the Hudson Bay area has had predominantly SW winds throughout much of November (caused by the large upper trough over the eastern seaboard and the upper high over Greenland dragging the air up from the south - without that Europe wouldn't have had the intense cold on this side of the Atlantic caused by the compensatory N/E/NE flow).

The attached link explains the current position of the freeze-up in Hudson Bay and indicates that it will be around 2 - 3 weeks behind by mid-December - but then what else would one expect when air is being dragged up from a warm source? It's called synoptics - those same synoptics that caused the polar ice minima in 2007, which incidentally has been recovering ever since and is still above 2007 levels despite the recent unfavourable synoptics for this important (by that meaning relatively large) area.

To try and link this to something more sinister betrays entrenched beliefs, rather than an objective interpretation of the large -scale synoptic N. Hemisphere pattern - doesn't it?

http://ice-glaces.ec..._0005295169.txt

[paul tall]

malby, on 05 December 2010 - 13:09 , said:

I think the poster is attempting to state that this is all down to AGW when, more probably, all that has happened is that the Hudson Bay area has had predominantly SW winds throughout much of November (caused by the large upper trough over the eastern seaboard and the upper high over Greenland dragging the air up from the south - without that Europe wouldn't have had the intense cold on this side of the Atlantic caused by the compensatory N/E/NE flow).

The attached link explains the current position of the freeze-up in Hudson Bay and indicates that it will be around 2 - 3 weeks behind by mid-December - but then what else would one expect when air is being dragged up from a warm source? It's called synoptics - those same synoptics that caused the polar ice minima in 2007, which incidentally has been recovering ever since and is still above 2007 levels despite the recent unfavourable synoptics for this important (by that meaning relatively large) area.

To try and link this to something more sinister betrays entrenched beliefs, rather than an objective interpretation of the large -scale synoptic N. Hemisphere pattern - doesn't it?

http://ice-glaces.ec..._0005295169.txt

Thank you.

That was what I was wanting to establish, is this late freeze a one off (caused by unusual synoptics you state), and if it is a one off not a regular occurance, then what is Gray Wolf's point?

[Weather Ship]

I posted much of this a couple of months ago in, surprise surprise, a thread entitled, 'The North Atlantic Current is Gone', but I'll add a bit and post it again if it's of interest.

Oceanic influence along the Atlantic Coasts of the North America are very limited, although there is some moderating effect of mininimum temperatures at coastal stations. An example would be Labrador whose coast is fringed by the waters of a cold current, analogous to the Oyashio (Kuroshio) off East Asia, but in both cases prevailing westerlies greatly limit their climatic significance. As has been mentioned in previous posts the same prevailing westerlies carry heat from the Gulf Stream that effects climatic conditions in north west Europe. If you have a sustained blocking of the westerlies then this is bound to be significant and not the GS. Sound familiar?

A few thoughts on the Gulf Stream.

With the trade winds blowing westward across the oceans in tropical latitudes and prevailing westerlies blowing eastward at higher latitudes, it is understandable why the current gyres should form the dominant surface current pattern in the low and midlatitudes. What isn’t so obvious, however, is the reason why these currents should be so swift and narrow along the oceans’ western boundaries. What could possibly cause this western intensification of surface currents?

The Gulf Stream is just one of these swift narrow western boundary currents. A look at the diagram shows that there are similar intensified boundary currents along the western edges of all oceans, in both hemispheres. From considerations of the winds alone, you should think that each current could be half an ocean wide. But they are not, so are why they are so swift and narrow, and why do they occur on the western ocean margins only.

There are three related processes that contribute to the creation of strong narrow western boundary currents, all of which are products of the Earth’s rotation and atmospheric circulation. The first cause is that when an equatorial surface current runs into the continent on the ocean’s western margin, it “squirts out the sides, just like water in a stream that strikes a rock, or water from a garden hose that strikes the side of a building.

Second, the Coriolis deflection is stronger in the portion of the gyres at higher latitudes, where these eastward-flowing waters are deflected toward the equator. This pinches the equatorial currents and tends to prevent them from leaving the equator until they reach the very western end.

The fact that the strength of the Coriolis deflection increases at higher latitudes produces another related effect. When this water is flowing east, it gets deflected quickly toward the equator, whereas when it is flowing west, it is very close to the equator and gets deflected only very weakly. Consequently, the water tends to flow farther to the west than toward the east in any complete cycle, and the gyre tends to move westward across the ocean each time the water flows around it. This westward tendency forces the gyre up against the western margins where the currents are correspondingly compressed and intensified.

The third cause of the intensified western boundary currents is also related to the earth’s rotation, through the apparent change in the rotational state of objects moving north or south along the Earth’s surface.

A mass of water starting on the equator with no spin at all appears to acquire a spin as it goes. The farther poleward it goes, the faster it appears to spin. At intermediate latitudes, this amount of spin is less than one complete revolution per day. But if the water mass is wide, it doesn’t have to spin very rapidly for the outer regions to have high speeds. For example, a water mass 1000 kilometers wide and spinning only half a revolution per day would have to move at 65 kilometers per hour on its outer boundary!

Because of the dominant wind-induced current gyres, surface waters in the western portions of all oceans are traveling away from the equator. As these water masses go toward the pole, they acquire the appropriate spin (clockwise in the Northern Hemisphere and counter clockwise in the Southern Hemisphere) to make the current on the very western edge extremely swift.

Taking all of that into account I suspect although the GS may well vary in intensity over periods it is certainly not a cause for alarm. The NAC is another kettle of fish. The flow is weaker anyway and if the atmospheric western circulation in those latitudes suffered sustained spells of disruption then possibly this and the coriolis could severely slow it down. But this is just a guess.

EDIT.

Not to be foregotten. Ocean currents account for a significant proportion of the poleward heat transfer in low latitudes. Fairly recent satellite estimates of the required total poleward energy transfer indicates that the previous figures are too low. The ocean transport may be 47% of the total at 30-35N and as much as 74% at 20N; the Gulf Stream and the Huro Shiro currents are particularly important.

Large scale surface currents. (Source: Keith Stowe-Exploring Ocean Science)

Edited by weather ship, 05 December 2010 - 14:04 .

[cyclonic happiness]

Gray-Wolf, on 05 December 2010 - 10:49 , said:

I'd imagine that Moscow is augmented by an inner continental climate type with home grown deep cold blocking most warmer incursions (like the Arctic used to before we mucked it up?) whereas we're by fluid water....check the coastal temps this a.m. compared with those up hills/middle of the Island.

Where we to loose the N.A.D. we'd still need to freeze the seas around us to allow any 'continental cold' to live over us for the winter and looking at Baffin/Hudson Bay this may well be becoming a thing of the past.......

Even if the NAD shuts down, surely it would still take quite a few years to get rid of enough residual heat in the NA for ice to start to form around Britain, and wasn't there a few bits of sea ice forming off the coasts of Britain last winter as well as even some in November?
Could be a start (cue the "3 cold winters doesn't make a trend" )

Edited by cyclonic happiness, 06 December 2010 - 08:53 .