08-31-2021-1138 - Milutin Milanković Milankovitch

Milutin Milanković (sometimes anglicised as Milankovitch; Serbian Cyrillic: Милутин Миланковић [milǔtin milǎːnkoʋitɕ]; 28 May 1879 – 12 December 1958) was a Serbian mathematician, astronomer, climatologist, geophysicist, civil engineer and popularizer of science.

Milanković gave two fundamental contributions to global science. The first contribution is the "Canon of the Earth’s Insolation", which characterizes the climates of all the planets of the Solar system. The second contribution is the explanation of Earth's long-term climate changes caused by changes in the position of the Earth in comparison to the Sun, now known as Milankovitch cycles. This explained the ice ages occurring in the geological past of the Earth, as well as the climate changes on the Earth which can be expected in the future.

He founded planetary climatology by calculating temperatures of the upper layers of the Earth's atmosphere as well as the temperature conditions on planets of the inner Solar system, Mercury, Venus, Mars, and the Moon, as well as the depth of the atmosphere of the outer planets. He demonstrated the interrelatedness of celestial mechanics and the Earth sciences and enabled a consistent transition from celestial mechanics to the Earth sciences and transformation of descriptive sciences into exact ones.

https://en.wikipedia.org/wiki/Milutin_Milanković

The Cyrillic script (/sɪˈrɪlɪk/ sə-RIL-ik) is a writing system used for various languages across Eurasiaand is used as the national script in various Slavic, Turkic, Mongolic, Uralic, Caucasian and Iranic-speaking countries in Southeastern Europe, Eastern Europe, the Caucasus, Central Asia, North Asiaand East Asia.
As of 2019, around 250 million people in Eurasia use Cyrillic as the official script for their national languages, with Russia accounting for about half of them.^[4] With the accession of Bulgaria to the European Union on 1 January 2007, Cyrillic became the third official script of the European Union, following the Latin and Greek alphabets.^[5]

https://en.wikipedia.org/wiki/Cyrillic_script

 

	Orbital Variations  Changes in orbital eccentricity affect the Earth-sun distance. Currently, a difference of only 3 percent (5 million kilometers) exists between closest approach (perihelion), which occurs on or about January 3, and furthest departure (aphelion), which occurs on or about July 4. This difference in distance amounts to about a 6 percent increase in incoming solar radiation (insolation) from July to January. The shape of the Earth’s orbit changes from being elliptical (high eccentricity) to being nearly circular (low eccentricity) in a cycle that takes between 90,000 and 100,000 years. When the orbit is highly elliptical, the amount of insolation received at perihelion would be on the order of 20 to 30 percent greater than at aphelion, resulting in a substantially different climate from what we experience today. Obliquity (change in axial tilt)  As the axial tilt increases, the seasonal contrast increases so that winters are colder and summers are warmer in both hemispheres. Today, the Earth's axis is tilted 23.5 degrees from the plane of its orbit around the sun. But this tilt changes. During a cycle that averages about 40,000 years, the tilt of the axis varies between 22.1 and 24.5 degrees. Because this tilt changes, the seasons as we know them can become exaggerated. More tilt means more severe seasons—warmer summers and colder winters; less tilt means less severe seasons—cooler summers and milder winters. It's the cool summers that are thought to allow snow and ice to last from year-to-year in high latitudes, eventually building up into massive ice sheets. There are positive feedbacks in the climate system as well, because an Earth covered with more snow reflects more of the sun's energy into space, causing additional cooling.		On the Shoulders of Giants  Milutin Milankovitch  Orbital Variations  Milankovitch Theory  Links and References Left: The eccentricity of the Earth's orbit changes slowly over time from nearly zero to 0.07. As the orbit gets more eccentric (oval) the difference between the distance from the Sun to the Earth at perihelion (closest approach) and aphelion (furthest away) becomes greater and greater. Note that the Sun is not at the center of the Earth's orbital ellipse, rather it is at one of focal points. Note: The eccentricty of the orbit shown in the lower image is a highly exaggerated 0.5. Even the maximum eccentricity of the Earth's orbit—0.07—it would be impossible to show at the resolution of a web page. Even so, at the current eccentricity of .017, the Earth is 5 million kilometers closer to Sun at perihelion than at aphelion. (Images by Robert Simmon, NASA GSFC)

https://earthobservatory.nasa.gov/features/Milankovitch/milankovitch_2.php

Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term is named for Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypothesized that variations in eccentricity, axial tilt, and precession resulted in cyclical variation in the solar radiation reaching the Earth, and that this orbital forcing strongly influenced the Earth's climatic patterns. Similar astronomical hypotheses had been advanced in the 19th century by Joseph Adhemar, James Croll and others, but verification was difficult because there was no reliably dated evidence, and because it was unclear which periods were important. Now, materials on Earth that have been unchanged for millennia (obtained via ice, rock, and deep ocean cores) are being studied to indicate the history of Earth's climate. Though they are consistent with the Milankovitch hypothesis, there are still several observations that the hypothesis does not explain. https://en.wikipedia.org/wiki/Milankovitch_cycles