Posted on 05/16/2023 1:03:28 PM PDT by Red Badger
Artist’s impression of how astronomical forces affect the Earth’s motion, climate, and ice sheets. Credit: NAOJ
A team of researchers, including climatologists and an astronomer, has utilized an enhanced computer model to recreate the ice age cycles that occurred between 1.6 and 1.2 million years ago. The findings indicate that the glacial periods were primarily influenced by astronomical forces in quite a different way than it works in the present day. This information will contribute to a more comprehensive understanding of ice sheets and the Earth’s climate throughout the past, present, and future.
The slow, gradual changes in the Earth’s orbit around the Sun and the orientation of its spin axis are influenced by the gravitational forces exerted by the Sun, Moon, and other planets. These astronomical factors impact Earth’s environment by altering the distribution of sunlight and the distinctions between seasons. Ice sheets, in particular, are highly responsive to these external forces, leading to cycles of glacial and interglacial periods.
The present-day glacial-interglacial cycle has a period of about 100,000 years. However, the glacial cycle in the early Pleistocene (about 800,000 years ago) switched more rapidly, with a cycle of about 40,000 years. It has been believed that astronomical external forces are responsible for this change, but the details of the mechanism have not been understood. In recent years, it has become possible to investigate in more detail the role of astronomical forces through the refinement of geological data and the development of theoretical research.
A team led by Yasuto Watanabe at the University of Tokyo focused on the early Pleistocene Epoch from 1.6 to 1.2 million years ago using an improved climate computer model. Astronomical forces based on modern state-of-the-art theory are considered in these simulations. The large numerical simulations in this study reproduce well the glacial cycle of 40,000 years of the early Pleistocene as indicated by the geological record data.
From the analysis of these simulation results, the team has identified three facts about the mechanisms by which astronomical forces caused changes in climate in those times. (1) The glacial cycle is determined by small differences in the amplitude of variation of the spin axis orientation and the orbit of the Earth. (2) The timing of deglaciation is determined mainly by the position of the summer solstice on its orbit, which is at perihelion, not only by the effect of periodical change of the tilt of the Earth’s axis. (3) The timing of the change in the spin axis orientation and the position of the summer solstice on its orbit determines the duration of the interglacial period.
“As geological evidence from older times comes to light, it is becoming clear that the Earth had a different climatic regime than it does today. We must have a different understanding of the role of astronomical forcing in the distant past,” says Takashi Ito from the National Astronomical Observatory of Japan, a member of this research team who led the discussion on astronomical external forces.
“The numerical simulations performed in this study not only reproduce the Pleistocene glacial-interglacial cycle well but also successfully explain the complex effects of how astronomical forcing drove the cycle at that time. We can regard this work as a starting point for the study of glacial cycles beyond the present-day Earth.”
Reference: “Astronomical forcing shaped the timing of early Pleistocene glacial cycles” by Yasuto Watanabe, Ayako Abe-Ouchi, Fuyuki Saito, Kanon Kino, Ryouta O’ishi, Takashi Ito, Kenji Kawamura and Wing-Le Chan, 15 May 2023, Communications Earth & Environment. DOI: 10.1038/s43247-023-00765-x
The study was funded by the Japan Society for the Promotion of Science.
Not our fault.......................
earth is moving around a sun that fluctuates in intensity and heat... the sun moves around a universe that i am sure has differences in temperatures, and we blame the smallest insignificant element of all—man.
That’s nice and all, but the great scientist Sandy Cortez has assured us that astronomical forces can be overcome with taxes and politics.
People are slowly beginning to see this ‘Climate Change’ for the scam that it is.................
Agreed. But I read this as the left’s way to attempt to silence those of us who say to quit bleating about global warming as we point to past warming and cooling cycles. I think they’re basically saying at least one cycle in the past was unusual so we can’t use it as a basis to explain the current cycle (which they say isn’t a cycle).
Unpossible. Before global warming the earth’s temperature was a constant 72F, then came White Supremecist Republicans driving SUVs.
The leftists real agenda is to shut down western developed man and his commerce which developed capital and capitalists.
Are they attacking China, India and the BRICS?
Of course not. They attack the west because the west is the most powerful. They're bringing down the big boys first. IMHO, the west became great because of the First and Second Great Awakenings. Sure the English speaking people were powerful before the Awakenings. But before the Awakenings, the British Empire was just yet another empire in the history of empires. The Awakenings changed that and did things like usher in freedom for the citizens, even abolition of slavery, and, yes, capitalism. All of those together within the most powerful culture at the time changed the world.
IMHO the left fears another awakening in the west more than they fear anything else.
THERE ARE FOUR LIGHTS!
I have often wondered if passing through a comet’s tails affects weather. It always seems unseasonably cold and/or rainy during Meteor showers.
True that! And not only was it a constant 72F, the rain was constant, the droughts were constant, snowfall was constant, the number and intensity of tornado's and hurricanes were constant and so on.
Yup, so to fight white supremecist republicans, we must fight "climate change" to insist that the climate go back to being static.
There are still other factors.
The array of land is one. Most of the world’s continental landmass is in the Northern Hemisphere. When it, due to those forces described here, points away from the Sun, snow can accumulate quickly into ice sheets that grow and do not melt completely over each weak Summer period until you have continent-wide glaciers. This doesn’t happen as much in the Southern Hemisphere, as it has far more oceanic coverage and there’s just no place for the ice to accumulate except Antarctica and a small bit in Tasmania and the Southern Andes.
Another issue is the joining together of the North and South American continents, and the closing of the Tethys Sea, which reduced the global warm ocean currents, and produced a cold water current at approximately 60 degrees latitude South, which insulated Antarctica into its current ice box climate that hasn’t varied much in 25 million years, as it was sent by plate tectonics to the (bottom of the globe J/K) Southernmost part of the globe.
The Earth’s orbit, and axis tilt, and positions of the summer solstice, etc, have been the same for at least 85M years, if not more. The positions of the continents, which effect ocean currents, have been generally the same for 85M years, and nearly identical to today’s for 34M years. The only thing that has changed is the joining of No America and So America about 6M years ago, if I’m remembering my geology from 55 years ago correctly.
So haw do astronomical forces being on ice ages at periodic intervals, when that is not seen in the record before the current glacial period?
Wasted reading through three paragraphs to learn “...but the details of the mechanism have not been understood.”
The “greatest minds in science” really don’t have any idea.
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