How weather cycles are influenced by Earth’s orbit

March 7 () –

A new paradigm proposed by Stefano Pierini, from the Parthenope University of Naples (Italy), is capable of illustrating how climate cycles They are influenced by the Earth’s orbit.

Proxy data for Earth’s climate, found in places like corals, pollen, trees, and sediments, show interesting oscillations roughly every 100,000 years from now. about 1 million years.

Strong changes in global ice volume, sea level, carbon dioxide concentration, and surface temperature indicate cycles of a long, slow transition to an ice age. and an abrupt change to a warm and short interglacial period.

Milutin Milankovitch hypothesized that the timing of these cycles was controlled by Earth’s orbital parameters, including the shape of its path around the sun and the planet’s tilt. A slightly closer orbit or a more tilted planet could create a small increase in solar radiation and a feedback loop causing massive changes in climate. This idea suggests that there may be some predictability in the weather, a notoriously complex system.

Now, Stefano Pierini proposes a new paradigm to simplify the verification of Milankovitch’s hypothesis. “The main motivation for this study was the desire to characterize and illustrate Milankovitch’s hypothesis in a simple, elegant and intuitive way”, says this scientist, who has published his conclusions in Chaos magazine.

Many models suggest that Milankovitch is correct, but these methods are often detailed and study-specific. They incorporate climate feedback loops — for example, increased ice cover reflects more radiation back into space, causing more cooling and more ice cover — as threshold crossing rules. This means that an abrupt jump in climate only occurs when a parameter reaches a certain turning point.

He “deterministic arousal paradigm” Pierini’s combines the physical concepts of relaxation oscillation and excitability to link Earth’s orbital parameters and glacial cycles in a more generic way.

The relaxation oscillation component describes how the climate slowly returns to its original glacial state after being disturbed. At that time, the excitability component of the model it captures the outer orbital changes and triggers the next glacial cycle.

Using his own threshold crossing rules and adopting a classical energy balance model, Pierini obtained a correct and robust timing of the most recent glacial cycles.

“The application of the deterministic excitation paradigm in its current basic formulation can explain the chronology of the last four glacial completions,” he says. Extending the same analysis to the entire Pleistocene will be the subject of future research.”

Pierini believes that similar methods could be used in other fields of nonlinear science and in relation to other weather phenomena.