Physics of the Earth’s Glacial Cycle

• Published in: Foundations
• Main Author: Boris M. Smirnov
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2022
• Subjects: glacial cycle; EPICA project; climate in past; volcano eruptions; atmospheric temperature; Mathematics; QA1-939; Antarc*; Antarctica; EPICA
• Online Access: https://doi.org/10.3390/foundations2040073; https://doaj.org/article/67f0f563d39f42ec8e61649dd7106aa9

The evolution of the atmospheric temperature in the past, resulted from the EPICA project (European Project for Ice Coring in Antarctica) for the analysis of air bubbles in ice deposits near three weather stations in Antarctica, includes several glacial cycles. According to these studies, the glacial cycle consists of a slow cooling of the Earth’s surface at a rate of about <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></semantics></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math> C per year for almost the entire time of a single cycle (about 100 thousand years) and of a fast process of heating the planet, similar to a thermal explosion. The observed cooling of the planet follows from the imbalance of energy fluxes absorbed by the Earth and going into its surrounding space, and this imbalance is four orders of magnitude less than the accuracy of determination of the fluxes themselves. The inconsistency of the popular Milankovich theory is shown, according to which glacial cycles in the evolution of the Earth’s thermal state are associated with changes in the Earth’s orbit relative to the Sun. In considering the glacial cycle as the transition between the warm (contemporary) and cold thermal states of the Earth with a difference in their temperatures of 12 <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math> C according to measurements, we construct the energetic balance for each of Earth’s states. The fast transition between the Earth’s cold and warm states results from the change of the Earth’s albedo due to the different volcano activity in these states. ...