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Post by spaceman on Nov 12, 2009 3:46:53 GMT
no, the equator would have the same weather it is having now. If in fact the sudden end of the ice age occurred in one year the way the earth revolves around the sun could explain it. I saw this motion. One hemisphere moves around the sun away while the other point toward. All of the other effects of planet tilt and the eccentricity of the orbit would progress the same. Someone on here mentioned that as long as the south pole has land mass it seems we have ice ages. I thought that perhaps the accumulation of ice over the south pole would have the effect I am talking about. The earth still spins, it still revolves around the sun, still has a tilt, which continues to move between maxmia and min and the orbit acts the same way. The difference that would cause a sudden onset of an ice age would be the position of the earth axis as it circles the sun. I was looking for a reason why animals froze to death while eating, why tropical plants grew at the poles. All of the other movements do not give a sufficient amount of cooling. Of course there could be a number of other things. A dust cloud that sits between us and the sun, the earth and the sun are magnetically linked at 60 deg N and the sun could burp a cloud of liquid helium, which has been demonstrated to occur in nuclear reactions, and be pulled toward earth. These things could happen too. Ok, it would be like a wobble. To us the only difference we would see is that the seasons, and the sun, would swing between winter and spring in one hemisphere, and summer and fall in the other. The earth's core is liquid, I don't see any reason why this can't happen. I saw it happen with a top. In fact, after I saw it and realized what it might mean, I threw several more with the same result. ( it's the kind with string and you throw it) . At 0 deg the earth in the northern hemisphere is facing away and the southern is facing towards. At 90 deg there is equal daylight at both the northern and southern hemispheres, at 180 deg the northern hemisphere, instead of moving towards summer, moved back to winter, at 270 deg it moves back to equal daylight again, and at 360/0 deg it is winter again in the northern hemisphere. The tropics would remain warm. and even part of the area north of the tropics would be cold at times, but with spring it could be fairly nice. Limiting how far the glaciers advanced. The last time was as far south as Cincinnati, oh. I saw where the dirt and rock had been pushed up into a hill, called a moraine, I think.
Also, I was curious if tropical plants grew at both poles at the same time.
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Post by sinimod on Nov 29, 2009 21:12:14 GMT
Dansgaard-Oeschger (D-O) events and the assumed ~1,500 cycles may not have required any external forcing. They appear to be largely the result of regime shifts in thermohaline circulation. The thermohaline circulation (THC) transfers enormous amounts of heat from the southern to the northern hemisphere. Evidence suggests that during stadials in the northern hemisphere, the THC shut down; and during interstadials, the THC operated.
Perhaps you all are familiar with the concept of the bi-polar seesaw effect described by Blunier et al., 1998, which describes the leads and lags in the phase relationship between the Greenland and Antarctica temperatures (as derived from oxygen and hydrogen isotopic ratios from ice core sampling). The antiphasing of Greenland and Antarctica ice cores can be stratigraphically correlated using methane signatures in the ice cores. If these events were stimulated by changes in solar radiation, then there should be no stark differences in temperature changes between the hemispheres. As it is likely no external forcing was required to initiate D-O events, and the globally averaged heat content of the planet may not have changed, then there might not have been a triggering mechanism (ie. solar radiation changes) to stimulate the feedback response of increasing the concentration of atmospheric CO2.
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Post by nautonnier on Nov 29, 2009 22:39:29 GMT
In a chaotic system the stimulus to create a large state change does not have to be large - it just has to be in the right place at the right time and the right size.
It may be that at certain stages in the orbital dynamics the climate has wandered away from the attractor it is currently close to - and a stimulus at just that time can push it toward the other attractor. The stimulus may be a 'common' event that in normal times when the climate state is close to the attractor of an ice age or interglacial then nothing happens; but when at the edge of the effect of that attractor - the same stimulus could result in a sudden movement to the alternate attractor. It certainly looks like the Earth's climate is in a bi-stable state with the stronger attractor being the glacial periods.
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Post by aj1983 on Nov 30, 2009 0:00:22 GMT
This bistable state with the glaciation state being the most dominant is also currently taught in Climate Dynamics courses here. Orbital changes together with the inertial oscillation of large northern hemisphere ice sheets can explain the observed glaciation cycles. (Prof. J. Oerlemans) www.agu.org/pubs/crossref/1993/93PA02751.shtmlSeveral feedbacks are at work during these transitions, the major ones being albedo and CO2. Other factors may cause rapid (local) variations, like large variations in the THC.
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Post by william on Nov 30, 2009 1:38:52 GMT
The glacial/interglacial cycle is forced by massive CME that occur cyclically. The massive CME occur when the solar cycle restarts. There are concurrent burn marks on the planet's surface that have all been dated at specific time periods. The CME creates a space charge that creates a potential difference between the ionosphere and the earth's surface. There is then an electric strike from the ionsphere to the earths' surface. The CME affect the geomagnetic field constructively or desconstructively depending on the timing of perihelion. The finding of cyclic archeomagnetic jerks, there have been 10 in the last 5000 years is the smoking gun. There ice sheets are an insulator which shields the planet from the electric strikes moving them down to lower latitudes, which weakens the mechanism's ability to recharge the geomagnetic field. The insolation mechanism has a number of paradoxes. en.wikipedia.org/wiki/Milankovitch_cycles
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Post by william on Nov 30, 2009 1:39:54 GMT
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Post by william on Nov 30, 2009 1:44:09 GMT
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Post by william on Nov 30, 2009 1:49:14 GMT
Recent precision paleomagnetic analysis has found evidence of cyclic abrupt changes to the geomagnetic field which correlate with volcanic eruptions in the region where the geomagnetic field inclination changes occurs. The volcanic eruptions correlate with solar magnetic cycle minimums. As noted above it appears when the solar cycle restarts there are massive CME which create a space charge in the ionosphere which then creates a potential between the ionosphere and the planet's surface. There is then a series of massive electrical strikes from the ionosphere to the planet's surface. The electric strikes modulate the geomagnetic field cause an abrupt change in its inclination and changes to its intensity. In addition the massive electrical charges cause volcanic eruptions in the regions where the strike occurs. This is the paper that provides evidence of multiple volcanoes with different magma chambers all erupting in a short time period and all capturing a geomagnetic excursion. There are two anomalies noted in this paper. Volcanoes are fed by a magma chamber. The Auckland volcanoes in question are physically separated and hence cannot have shared the same magma chamber. There is hence no reason why the five geographically separated volcanoes would have erupted within a very short period of time. The second anomaly is that the magma flow from the five volcanoes when it cooled captured a magnetic field excursion where the direction of the geomagnetic field suddenly changed. Cyclic magnetic field excursion is a recent discovery. www.agu.org/pubs/crossref/200...GL027284.shtml
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Post by william on Nov 30, 2009 1:57:00 GMT
sciences.blogs.liberation.fr/...llot07EPSL.pdfAs I said the electric strikes that occur when the solar magnetic cycle restarts modulates the geomagnetic field causing abrupt planetary cooling and large volcanic eruptions. Volcanic eruptions only cool the planet for a few years. These cooling events are 500 years to 1000 years which matches the time constant for the geomagnetic field to adjust to the forcing change. Are there connections between the Earth's magnetic field and climate? www.pnas.org/content/101/17/6...#otherarticles
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Post by william on Nov 30, 2009 1:58:28 GMT
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Post by william on Nov 30, 2009 2:11:55 GMT
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Post by william on Nov 30, 2009 2:24:55 GMT
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Post by william on Nov 30, 2009 2:33:38 GMT
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