A revolutionary discovery: What is the relationship between ocean patterns and the planet's climate?

the General ocean circulation It is an essential component of the world's climate system LandWithout which a large portion of the Earth's surface would be covered in ice. This rotation involves motions covering a wide range of structures and scales, including jets such as Gulf Stream and KuroshioAnd the eddies and longitudinal circulation of the basin that extends for several thousand kilometers. The circulation also includes 100 km mesoscale turbulent eddies, which permeate the global ocean and contain most of the kinetic energy (KE).

Now, an international team of scientists has found the first direct evidence of this It links seemingly random weather systems In the ocean with Climate at the global level. The results were published in a publication in the journal Advancement of science.

The ocean has Weather patterns Similar to those we live on Earth, but in Different time and length scales. While terrestrial eddies can last a few days and are about 500 kilometers across, offshore ones, like eddies, can last three to four weeks, although they are roughly one-fifth the size.

It has long been speculated that these ubiquitous and seemingly random movements in the ocean communicate across climate scales, but this idea of ​​connection has always been vague because it has not been clear how to unravel this complex system to measure its interactions. Now specialists have developed a framework that can do just that.

The goal was to understand how energy passes through different ocean channels around the planet. They used a mathematical method developed in 2019, and later implemented with sophisticated code, which allowed them to study the transfer of energy across different patterns ranging from the circumference of the Earth to 10 kilometers. These techniques were then applied to ocean datasets from advanced climate model and satellite observations.

The study revealed this Ocean weather systems activate and weaken as they interact with climate parameters and in a pattern that reflects global atmospheric circulation. The researchers also discovered that there is an atmospheric band near the equator called “Intertropical convergence zone“, which produces 30 percent of global precipitation, causes intense energy transfer and produces turbulence in the oceans.

The study of fluid movement is so complex that it occurs at multiple scales and is not easy, but it has advantages over previous attempts to link weather to climate change. For this reason, this would be a promising framework to better understand the climate system.

There is great interest in how global warming and our changing climate will affect extreme weather events. These research efforts typically rely on statistical analyzes that require extensive data to be confident about uncertainties. In this paper a different based approach is adopted Automated analysis, which relaxes some of these requirements and allows cause and effect to be more easily understood.

The analysis provided an estimate of kinetic energy transfer at the global ocean scale, at scales ranging from 10 to 40 thousand kilometres. This action is induced by Hadley and Ferrell cells and polar cells in the atmosphere, and the intertropical convergence zone leads to intense KE transport on a descending scale.

High-level transmission reaches 300 GW over medium scales of 120 km, roughly one-third of the energy that wind contributes to the overall ocean circulation. Nearly three-quarters of this “cascade” occurs south of 15° S latitude and penetrates almost the entire water column.

The KE of these intermediate ranges follows the same cycle but peaks about 40 days after the cascade maximum, indicating that The energy transferred across one scale is essentially deposited onto a scale four times larger.

* Hussein Al-Alawi He is an associate professor in the Department of Mechanical Engineering at the University of Rochester.