| doug |
| (Weather Analyst) |
| Thu Dec 01 2005 09:29 PM |
Receding Gulf Stream
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The actual article was entitled "Alarm over dramatic weakening of Gulf Stream" attributed to Ian Sample Science correspondent for The Guardian , a British daily., published in The Guardian on Dec. 1, 2005.
The current is alleged to be 1/3 weaker over the last decade, attributed to Global Warming. It will allegedly lower the ambient temperature across Great Britian by a full degree in the next ten years resulting in more extreme weather, severe winters and cooler summers.
The source of the decline is attributed to the supposedly global warming effects of increased melt water from the Greenland and artic glaciers and increased runoff in rivers into the North sea from Russia. However the scientist had to note that the climatological record is consistent with this same phenomena in the distant past (pre Global gas emmisions into the ionosphere). The article also hedges on a conclusion that the effect noted is any thing other than a short term variation.
Needless to say I am a little putoff by Globl Warming becoming the cause of many climatologically explainable events such as increased hurricane activity also over that same decade.
Can there be any correlation between the alleged alteration of the flow of the current and the atmospheric patterns effecting the development of hurricanes in the North Atlantic?
| Domino |
| (Weather Guru) |
| Fri Dec 02 2005 03:17 AM |
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Re: Receding Gulf Stream
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Interesting thought. I suppose one would have to compare SST maps over the past several years...but I almost doubt there is enough data to really tell what is going on. Seems like if the gulf stream is weak...then there is nothing to carry the warm water out of the Atlantic and thus...warmer water?
| Clark |
| (Meteorologist) |
| Fri Dec 02 2005 05:22 AM |
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Re: Receding Gulf Stream
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I get the implication that the author is getting more at the diffusion of the Gulf Stream/North Atlantic Current due to mixing of the relatively warm water with cooler water that has melted from glaciers. Thus, you really aren't seeing more warm water in the Atlantic, just a sharper gradient and weaker overall current. I'm not sure that, if it exists, it is strong enough to be noticed or is anything more than a short-term phenomenon, both caveats mentioned by the author. Time will tell, I guess.
| WeatherNut |
| (Weather Master) |
| Fri Dec 02 2005 10:00 PM |
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Re: Receding Gulf Stream
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I've been following this for a couple of years...and quite honestly, its very alarming. There is only 1/4 of the normal amout of water sinking under the greenland shelf. This site is very good at explaining whats going on:
http://www.whoi.edu/institutes/occi/currenttopics/climatechange_wef.html
Basicly, when you get too much fresh water in the northern atlantic it does not sink as quickly since freshwater is less dense than saltwater. Ice traps the water leaving the salt. More ice=more salt Less ice=Less salt.
Freshwater can also "cap" the heat given off by the denser saltwater below...again, causing it to sink more slowly. Problem here is if the water does not sink...the warm waters flowing north to replace it... dont. How this would affect the hurricane season? I have no idea, but it would not take a huge leap to think that the oceans have to transfer heat to the northern lattitudes somehow. If you have a gulfstream thats not doing enough of it...hurricanes are the other way oceans transferr heat, so you would see more of them (I know this WAY more complicated)
| HanKFranK |
| (User) |
| Sun Dec 04 2005 05:53 AM |
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Re: Receding Gulf Stream
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well, i've seen studies that freshwater influx can shut off the nadw (north atlantic deep water) formation and others that say all they do is slow it down unless a really immense shock (like from a glacial dam giving way and letting a lake drain rapidly) comes by and knocks it off. i'd guess that an ice shelf falling off a continent into an ocean could do it as well, but most of what's up around the north atlantic is in interior greenland, and can't 'fall-in', so to speak. CO2 is high as well... if those scary model forecasts aren't overdoing things by orders of magnitude then the climate over much of the northern hemisphere is due to warm tangibly in the next couple of decades. and those model forecasts don't really scare me, come to think of it. ice ages are scary... interstadials are much better to live in.
just recently, though, i haven't seen any really huge cold sst anomalies in the north atlantic. it's been persistently warmer than the long term average (long term to us doesn't mean a lot in the grand scheme of things, though) for the last few years. if i had to make a forecast for the UK for the next decade, i'd say it'll be warm if anything. maybe some relation of vince will make a pass at them, who knows?
HF 0553z04december
Ed Dunham
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| (Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)) |
| Fri Dec 09 2005 02:38 PM |
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Re: Receding Gulf Stream
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Actually there is some new scientific thought (and concern) that has recently been featured on television. The premise is that a slow global warming could be nothing more than a natural event, primarily associated with major volcanic eruptions, that can create a follow-on mini ice age in a very short period of time. The premise is supported by ice core taps in the Arctic regions, Greenland, Siberia, etc., with short-term higher concentrations of trapped carbon dioxide and carbom monoxide emissions.
As described above, the theory is that a warming event creates glacial melt (even over land areas) and the runoff creates a significant increase of freshwater in the near-Arctic regions. The freshwater does not sink and can shut off any warm thermal current (i.e., the Gulf Stream). In this scenario, the North Atlantic loop current (and others) shuts down. Without the influence of the warm loop currents, the polar regions then rapidly cool and a mini ice age follows (with temperatures dropping about 7 degrees F along the entire east coast). Core samples suggest that sometimes this whole process can take place in less than two decades, i.e., much faster than previously thought.
ED