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Was the direction of oceanic currents changed during the ice age?

by Czcibor
Tags: changed, currents, direction, oceanic
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Czcibor
#1
Jun9-14, 06:47 AM
P: 78
Yes, curious about that.
(No, I'm NOT asking about some short term disturbances when glaciers were melting, but whether with lower temperature and part of continental shelf above water caused the currents to change their direction)
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D H
#2
Jun9-14, 07:19 AM
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Quote Quote by Czcibor View Post
Yes, curious about that.
(No, I'm NOT asking about some short term disturbances when glaciers were melting, but whether with lower temperature and part of continental shelf above water caused the currents to change their direction)
Why aren't you asking about those short term disturbances? That is the leading hypothesis of the cause of the Younger Dryas, a ~1000 year long interval at the end of the last glaciation when the Earth got very, very cold. This hypothesis claims that a temporary diversion of the cold meltwaters of Lake Agassiz to the St. Lawrence Seaway shut down the thermohaline circulation.
Czcibor
#3
Jun9-14, 08:23 AM
P: 78
Quote Quote by D H View Post
Why aren't you asking about those short term disturbances? That is the leading hypothesis of the cause of the Younger Dryas, a ~1000 year long interval at the end of the last glaciation when the Earth got very, very cold. This hypothesis claims that a temporary diversion of the cold meltwaters of Lake Agassiz to the St. Lawrence Seaway shut down the thermohaline circulation.
Because I forgot that 1000 years counts here as short term? ;)

Evo
#4
Jun9-14, 12:42 PM
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Was the direction of oceanic currents changed during the ice age?

Quote Quote by Czcibor View Post
Yes, curious about that.
(No, I'm NOT asking about some short term disturbances when glaciers were melting, but whether with lower temperature and part of continental shelf above water caused the currents to change their direction)
Back to your question,

Abstract
The Younger Dryas cold event is a relatively unique feature of the last deglaciation when compared to previous deglaciations, suggesting a unique trigger rather than the commonly held forcing mechanism of North American freshwater routing to the North Atlantic. Here, I compare the last (T-I) and penultimate (T-II) deglaciations and provide new support for the argument that the lack of a Younger Dryas-like event during T-II is due to the rapidity of Northern Hemisphere ice sheet retreat under greater boreal summer insolation forcing. Faster ice retreat suppressed Atlantic meridional overturning circulation (AMOC) until near the end of T-II, while during T-I AMOC increased relatively early. During T-I, the eastward routing of freshwater that caused the Younger Dryas happened after AMOC resumption, whereas during T-II this routing occurred prior to the resumption of AMOC. Thus the increased flux of freshwater to the North Atlantic during T-II had little effect on AMOC, explaining the lack of a Younger Dryas-like climate oscillation during this deglaciation.
http://www.sciencedirect.com/science...77379108000504
D H
#5
Jun9-14, 12:49 PM
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He's not asking about the Younger Dryas. That's a short term event in which Czcibor is not interested.
Evo
#6
Jun9-14, 12:54 PM
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I'm not posting about the Younger Dryas. Unfortunately it's only the abstract, but it discusses the differences between the T-I (last ice age) and T-II (previous ice age). Just going by the thread title, perhaps he's only wanting T-I information.
Czcibor
#7
Jun11-14, 03:17 AM
P: 78
D H. EVO:

Thanks!

(I thought more about long term difference, but this reminder about length of Dryas was also interesting)


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