Milankovitch cycles

milankovitch cycles and climate

The Milankovitch cycles it is based on the fact that orbital changes are responsible for glacial and interglacial periods. The climate varies according to three fundamental parameters that alter the movement of the Earth. Many people attribute climate change to Milankovitch cycles, but this is not the case.

For this reason, we are going to dedicate this article to telling you how the Milankovitch cycles work and how important a climate pair is for our planet.

What are Milankovitch cycles?

milankovitch cycles

We are facing one of the most important scientific models. Before the arrival of the Milankovitch cycle in the XNUMXth century, the factors that interfered with climate change on Earth were largely unknown in the scientific community. Researchers like Joseph Adhémar or James Croll they seek answers from the glaciations of the mid-nineteenth century to periods of drastic climate change. His publications and research were ignored until the Serbian mathematician Milankovic retrieved them and began to work on a theory that changed everything.

We now know how humans are influencing climate change, but it's also important to note that it's not the only factor. Climate change on Earth can also be explained by the influence of factors external to the planet. The Milankovitch cycles explain how orbital changes contribute to Earth's climate change.

Milankovitch cycle parameters

planet temperature

Weather is associated with orbital changes. Milankovitch believes that the sun's radiation is not enough to completely change the Earth's climate. However, changes in the Earth's orbit are possible. This is how they are defined:

  • Glaciation: high eccentricity, low tilt, and large distances between the Earth and the Sun result in little contrast between the seasons.
  • Interglacials: Low eccentricity, high tilt, and short distances between the Earth and the Sun, leading to different seasons.

According to the Milankovitch theory, it modifies the movement of translation and rotation of a planet based on three fundamental parameters:

  • The eccentricity of the orbit. It's based on how stretched the ellipse is. If the Earth's orbit is more elliptical, the eccentricity is greater, and vice versa if it is more circular. This variation can make a 1% to 11% difference in the amount of solar radiation that Earth receives.
  • Inclination. These are changes in the angle of the Earth's axis of rotation. The dip fluctuates between 21,6º and 24,5º every 40.000 years.
  • Precession We're talking about making the axis of rotation opposite the direction of rotation. Its effect on the weather is the result of changing the relative positions of the solstices and equinoxes.

The Serbian mathematician hopes to show in the early XNUMXth century that, in addition to human influence, we need to understand how our planet behaves and how orbital changes can alter the climate.

However, our role in climate change is undeniable. The human being is changing the behavior of the normal cycles of the Earth and the climate, so we must start to have a sustainable behavior that protects the environment.

Climatic consequences

temperature variations

Currently, because the Earth goes through perihelion during the northern hemisphere winter (January), the shorter distance from the sun partially buffers the winter cold in that hemisphere. Similarly, since the Earth is at aphelion during the northern hemisphere summer (July), at a greater distance from the sun it buffers the summer heat. In other words, the current structure of the Earth's orbit around the sun helps reduce seasonal temperature differences in the Northern Hemisphere.

On the contrary, the seasonal differences in the southern hemisphere have been accentuated. However, since summers are longer in the north and winters are shorter when the sun is farther from Earth, the difference in the seasonal energy pool received is not that great.

Theories

Traditional theories of paleoclimate suggest that glacialization and deglazing began at high latitudes in the northern hemisphere and spread to the rest of the planet. According to Milankovitch, a cooler summer is needed in the northern hemisphere's high latitudes to reduce summer melt and allow further snowfall. Autumn comes the winter before.

For this accumulation of snow and ice to occur, summer insolation must be low, which occurs when northern summer coincides with aphelion. This happened about 22.000 years ago, when the greatest glacial advance occurred (it also happens now, but with a greater impact than today due to the greater eccentricity of the orbit). Conversely, continental ice loss is favorable when high latitudes have high summer insolation and low winter insolation, resulting in warmer summers (more melt) and colder winters (less snow).

This situation reached a maximum about 11.000 years ago.. The perihelion and aphelion positions alter the seasonal distribution of solar energy and may have had a major impact on the last deglacial process.

However, it must be taken into account that the intensity of the radiation in summer is inversely proportional to the duration of the summer. This is due to Kepler's second law, which states that the Earth's motion speeds up as it passes through perihelion. This is the Achilles' heel of the theory that precession dominated the Ice Age. The dip is more important than the precession and the peculiarities of the precession when taking into account the integral of the intensity of the sun during the summer (or better yet, during the days when the northern mantle melts). The equinox precession cycle may be more decisive in tropical climates than in polar regions, where axial tilt appears to play a greater role.

I hope that with this information you can learn more about the Milankovich cycles and how they affect the climate.


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