Ice ages: Why North America is key to their coming and going

Now, a team of scientists from Japan, the US, and Switzerland suggests that the North American continent is the breeding ground for these cycles. It's a region where climate and the ice's effect on the Earth's crust play off each other to draw out the length of a glacial cycle triggered by changes in solar radiation that come with changes in Earth's orbit.

This feedback between climate and ice becomes most dramatic at the end of the cycle, when an ice sheet that has bulldozed its way too far south and gotten too heavy for its own good meets up with a warming climate.

www.csmonitor.com...

The study, led by Ayako Abe-Ouchi, a climate scientist at the University of Tokyo and the National Institute of Polar Research, resulted from a unique approach to modeling ice ages.

The study provides "good insights that clearly advance our understanding" of ice ages, notes Penn State University glaciologist Richard Alley, who was not involved in the study, in an e-mail. It also confirms aspects of ice ages that researchers have well in hand, he says.

The approach linked individual atmosphere, crust, and ice models in a way that needed only information on the amount of sunlight reaching Earth to generate ice-sheet behavior over the past 400,000 years that geologists have gleaned from more than a century of field studies.

Changes in the amount of solar radiation striking Earth come with changes in Earth's orbit occurring at intervals of 41,000, 23,000, and 19,000 years.

The study reaffirms that changes in the amount of summer sunlight striking northern high latitudes sets the process in motion. Indeed, changes to the shape of Earth's orbit over time, as well as long-term changes in the orientation of its axis, and their impact on solar radiation at high northern latitudes were the most significant astronomical influences in the team's simulations.

Still, the researchers "make a convincing case" that North America's shape and location on the globe, as well as the slow recovery of the crust as the ice begins to melt turn variations in solar radiation occurring in cycles measured in a few tens of thousands of years into a 100,000-year glacial cycle.

I wish I could post the whole article here, because it is really fascinating.

What makes North America so special?
"Maybe that's because the mountains deflect the polar jet stream farther south," says Dr. Raymo, referring to a high-altitude river of air that forms the boundary between cold polar air and warmer air to the south. Deep southward meanders in that river during modern winters can bring snow to regions where it's rare, such as the US Southeast. Or perhaps during the last glacial maximum the ice sheet covering Scandinavia was vulnerable to warm Atlantic Ocean water, she adds. "We don't know, in fact that's the next work we're doing – experiments to try to investigate that," she says.

That last statement--- The next work doing experiments....kinda cryptic. Would those who control the technology capable of altering natural weather patterns be so bold as to attempt bringing about an 'mini-ice age' just to satisfy scientific curiosity?

Good find.

S&F

reply to post by Stormdancer777


Well, Crap! Now we get blamed for the Ice Ages as well.

I think that the release of methane also plays a large role. The more methane released, the warmer things get, the more fresh water is introduced into the oceans screwing up the currents and then wham-o! A new ice age.

But it will happen over time, I don't foresee a "Day After" moment.

Its true.

The Ice Age franchise is produced by Blue Sky Studios, a division of 20th Century Fox...

It must be Sunday or my name.....

Interesting post OP.

Aside from changes in the Earths orbital patterns, the amount of solar activity is also thought to play a role in causing 'Ice Ages' here on Earth. In fact, our current solar cycle is experiencing an unexpected low point in solar activity, and scientists are already indicating the possibility of another 'little ice age'; similar to the one that occurred during the 16th century. - It's not 100% certain, but studies have linked the last mini ice age to low solar activity, and an event known as the Maunder Minimum.

The current solar activity cycle, possibly the weakest in 100 years, is approaching its maximum. This may signal a future low period for the sun, probably not unlike the one that caused the so-called Little Ice Age from the mid-16th to mid-19th centuries.

Solar activity can be easily monitored by the number of sun spots. Regular recordings of the phenomenon have been available since the middle of the 18th century, with the star’s activity reaching peaks about every 11 years. The current Solar Cycle 24, is about to pass its prime in a matter of months, according to observations.

Maunder Minimum is a period between about 1645 and 1715, in which sunspots became extremely rare. In fact some 18th century astronomers believed sunspots to be a myth. The period coincides with the so-called Little Ice Age, a time when the climate became cold enough for the River Thames in London to freeze in winter. On the gloomier side, the colder summers and harsh winters sealed the fate of the Viking colonies in Greenland, as its population starved and died out.

rt.com...

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changes within the sun and changes in Earth’s orbit...

Climate is influenced by natural changes that affect how much solar energy reaches Earth. These changes include changes within the sun and changes in Earth’s orbit.

Changes occurring in the sun itself can affect the intensity of the sunlight that reaches Earth’s surface. The intensity of the sunlight can cause either warming (during periods of stronger solar intensity) or cooling (during periods of weaker solar intensity). The sun follows a natural 11-year cycle of small ups and downs in intensity, but the effect on Earth’s climate is small. [1] [5]

Changes in the shape of Earth’s orbit as well as the tilt and position of Earth’s axis can also affect the amount of sunlight reaching Earth’s surface. [1] [2]

www.epa.gov...


Thanks for the share -
It's all an intricately linked puzzle,
and the end result is uncertain.

Originally posted by TDawgRex


But it will happen over time, I don't foresee a "Day After" moment.

If Yellowstone blows, it will happen.

When this does happen (and we are certain it will), it will cause untold "disruption". Those within the vicinity will be incinerated as temperatures from the lava flow can reach up to 500 degrees, meaning all surrounding cities will be utterly destroyed. If you somehow managed to survive the fast flowing lava, the thick ash cloud that would rain down would choke you to death. All the states surrounding Wyoming would certainly perish very quickly.

The UK and the rest of Earth would not escape. We would all be affected, wherever we were. Global temperatures would plummet by at least 21 degrees. This could last for many years, meaning that all plant life will slowly die off. We will have no vegetables; animals -- our meat -- will have no food, so humankind would likely starve.

What would happen if: A super volcano erupted?

reply to post by sonnny1


That thought hadn't occured to me, but when you're right...you're right.

That is one scenario I don't like contemplating.

reply to post by TDawgRex


Scary thought, hey? Even scarier is someone with this knowledge helping it happen. That scares me the most.

When looking at the globe, it is very clear that N America juts out much further into the Arctic Ocean than Asia. In addition, the warm Atlantic currents li e up nicely to flow into the Asian side of the coast, so it makes a great deal of sense that the glaciers would build up on the American side of the Arctic first. The land based glaciers would build up without the warm current from the Atlantic to melt the ice in the summer.

A point I didn't see made, is that N America is moving south west at about an inch a year. This is very slow, mile every 60,000 years, but a considerable gap has opened up allowing a great deal more of the warmer Atlantic current to enter the Arctic.

I am surprised not to see any speculation on how this might effect future ice ages.

m.youtube.com...

Originally posted by poet1b

A point I didn't see made, is that N America is moving south west at about an inch a year.

Shhhh! Can't you see that this is the plan to invade China?

It may take a minute or two but no one will see it coming! Who needs Marines when you can step from one shore to the next? ( No offense JarHeads! )

reply to post by Stormdancer777


You might want to check out the following YouTube video Hyper Earth: The New World, describing the patterns of the Jet Streams and Gulf Streams:



Short documentary but straight to the point....with nice visuals. Wait until the end to see an interesting ending.

~ Kratos

So the whole world really does revolve around America?

So the huge land mass known as Russia has no effect on anyones weather at all? I believe Russian Siberia has a four month snow free time out of each year, all that eight month cold air mass just sitting there is of no consequence?

Make sense.Good thread