3D model helps researchers understand climate impact of eddies

Mesoscale eddies are oceanic eddies less than 100 kilometers in diameter that are responsible for local “weather” in the ocean. Because of the large amounts of mass and energy transfer associated with these currents, mesoscale eddies play an important role in determining Earth’s climate.

To better understand how mesoscale eddies affect the Earth’s climate system, we can provide three-dimensional renderings of these large water eddies to understand how their heat and mass interact with other climate processes over time. You need to model how they interact. To address this problem, a group of oceanographers from Ocean University in Qingdao, China, and Fudan University in Shanghai, China, optimized mesoscale eddies to better predict future climate change. I wrote a review outlining how to model it.

The group published a review on July 15 in the online journal Ocean-Land-Atmosphere Research.

“The complexity of (mesoscale eddy) structures, including horizontal and vertical structure, temporal evolution, and fine structure, poses challenges in fully capturing their impacts on climate-related processes. This paper addresses these To address the challenges of Zhengguang of Physical Oceanography Laboratory, Ocean University Professor Zhang said.

The researchers noted that the horizontal structure of mesoscale eddies is much better understood than the vertical structure, due to their size and better observation capabilities, and is easier to model in laboratory experiments and numerical models. As a sea eddy, the horizontal structure of a mesoscale eddy automatically forms a circular shape. It is very similar to galaxies, Jupiter’s Great Red Spot, and hurricanes. as the minimum energy state.

This spontaneous process, called axial symmetrization, occurs when an elliptical vortex rotates around its central axis and loses small filaments to form a horizontal circular vortex. However, in crowded ocean environments, this circular shape is only temporary and is often deformed by other eddies, changes in water density or bathymetry, or strong atmospheric processes such as hurricanes.

However, mesoscale vortices do not only exist in two dimensions. Modeling the 3D shape of these vortices also requires accurately predicting the vertical axis, which is much more difficult to measure. Mesoscale eddies can reach the ocean floor and account for most of the ocean’s kinetic energy. Also, due to the complex motions that occur in the ocean, the vertical axis can easily be tilted by changes in water density or large-scale currents, so it is very unlikely that a perfect vertical axis will form in a mesoscale eddy. will be lower.

The lifespan of an eddy consists of three distinct stages: formation, maintenance, and destruction, and better characterizing these dynamics over time can help researchers better model these structures. Helpful. From the beginning of an eddy as an instability in the ocean, to the growth of an eddy until it absorbs energy, strengthens, and forms an axisymmetric circle, the 3D structure of an eddy is a dynamic process that changes state and shape. is constantly influenced by oceanic and atmospheric forces. Vortex.

All these factors can make it extremely difficult for researchers to effectively model eddies and their effects on global energy dynamics. This study highlights the importance of incorporating vertical and horizontal axes, their associated structures, and the evolution of eddies over time into a unified framework.

“Based on this unified framework of mesoscale eddy structure, we can (easier) understand the effects (of eddies) on ocean energy cascades, heat and water mass transport, and nutrient and chlorophyll distribution. “Mesoscale eddies need to be incorporated into a broader integrated framework to understand their role in the overall climate system and biogeochemical cycles,” said Zhang.

The research team acknowledges that further research is needed to accurately represent the influence of mesoscale eddies in climate models.

“Future research will focus on improving 3D structural models of mesoscale eddies and integrating these insights into climate models. “By accurately representing the dynamic role of eddies, we can strengthen predictive climate models and lead to more reliable predictions of climate change,” Zhang said.