Sentences with phrase «with precession cycles»

And, orbital tuning won't create exactly the * combination * of frequencies (as is clearest with precession cycles) that match the astronomical cycles.

Not exact matches

In particular, there was no sign of climate change in Indonesia associated with Earth's orbital precession, a wobble caused by Earth's axis tilt that generates differences in sunlight in a 21,000 - year cycle.

Vetoretti and Peltier (2004) found that glacial inceptions can be caused either by a strong obliquity forcing or by a combination of eccentricity - precession forcing and low CO2 values, which is in line with results from Berger and Loutre (2001) who found that CO2 is important during times like the MIS - 11, when the insolation variations are too small to drive glacial - interglacial cycles.

If the Earth were completely symmetrical across the equator, the effect of precession would by a ~ 20,000 (I'm rounding) year cycle, but with two cycles of the global average in that time (with perihelion going from solstice to equinox to solstice completing one such global average cycle).

There's also a cluster of small peaks in the range 0.042 to 0.045 cycles / kyr (periods 22,000 to 24,000 years) and a small peak at 0.053 cycles / kyr (period 19,000 years) that are all coincident with periods in the changes of precession, the orientation of earth's spin axis relative to the longitude of perihelion (closest approach to the sun) of earth's orbit.

For a completely carbon - dioxide - free reconstruction of the Vostok temperatures since 450 000 years refer to O. G. Sorokhtin (references on card n ° 7) chapter 4.4 pp. 180 - 190 Precession Cycles and the Earth Climate: it explains in detail and computes the quick de-glaciations observed by G.Roe and by Lisiecki & Raymo, with all the «saw - teeth».

Precession alone is powerful enough to drive a 20,000 year cycle wherein the Sahara alternates between a lush, wet land with three giant interconnected lakes and the desert we see today.

The LR04 age model establishes that MIS 11 spans two precession cycles, with 18O values below 3.6 o / oo for 20 kyr, from 398 - 418 ka.

Might the «weather» of orbital cycles be impacted by K / T but not the «climate» — perhaps the trajectories of obliquity, precession and eccentricity would become completely different given sufficient time, but maybe with the same general character — periods and amplitudes and average values being similar enough that a casual glance at any given time segment (on the necessary scale to characterize the orbital cycle «climate») wouldn't look like anything different.