Researchers undertook a study of the ocean’s topography to better understand its impact on Earth’s climate. They found that realistic seafloor topography can sustain and reshape the key features of climate system even when continents are removed. Their research was published in the journal Ocean-Land-Atmosphere Research on August 25, 2026.
“We aimed to better understand the role of ocean bathymetry in shaping the large-scale ocean circulation and global climate. Specifically, by retaining realistic ocean bathymetry while removing continents, we investigated to what extent bathymetry alone can sustain the large-scale circulation and asymmetric climate characteristics of the two hemispheres,” said Peixi Wang, a postdoctoral researcher at Sun Yat-sen University.
From a big picture perspective, the global climate determines where people live, what plants and animals thrive, and how people grow food and pursue their economic activity. Scientists know that topography plays an important role in shaping Earth’s climate system. It influences atmospheric circulation, energy transport, and ocean dynamics. However, scientists are less certain of how bathymetry, land-sea distribution, and continental topography contribute to the climate system.
Much of what scientists know about topography has been derived from idealized modeling frameworks. These include atmospheric general circulation models (AGCMs), AGCMs coupled with slab ocean models, and fully coupled general circulation models. Aquaplanet simulations are idealized computer models of Earth where the seafloor, land, mountains, and sea ice are removed with only a global ocean remaining.
They performed two experiments using the fully coupled Community Earth System Model v.1.2.2. One of the experiments was a control experiment with the present-day Earth geography. They called this control experiment REAL. The other experiment was an aquaplanet experiment where the land was replaced with a 10-meter-deep ocean with the original ocean bathymetry preserved. They called the aquaplanet simulation they created BATHY. The BATHY experiment allowed the researchers to examine how realistic seafloor topography organizes ocean and atmospheric circulation in the absence of continents and land-surface processes.
Their model results showed that, compared with the real Earth, BATHY retains a similar large-scale ocean circulation but exhibits an overall strengthening. As the ocean currents shift and the wind systems move the global heat, the Antarctic gets warmer and the Arctic gets colder.
“Our results show that ocean bathymetry plays an important role in shaping the global climate system through its regulation of large-scale ocean circulation and heat transport,” said Wang. Even without continents, realistic bathymetry can sustain a deeper Atlantic Meridional Overturning Circulation (AMOC), while a Pacific Meridional Overturning Circulation (PMOC) also emerges. These changes in large-scale ocean circulation substantially reorganize meridional heat transport and the global climate. “Notably, hemispheric climate asymmetry persists in the Bathyplanet configuration because of the existence of AMOC, although it is substantially reduced compared with the real-world configuration, highlighting the combined roles of ocean bathymetry and continental geometry in shaping Earth’s climate,” said Wang.
Overall, the BATHY experiment highlights the important role of oceanic topography in driving the modern Earth’s climate in the absence of land surfaces. Ocean topography is not merely a passive boundary beneath the ocean. The shape of the ocean floor not only regulates coupled ocean–atmosphere dynamics through its control of large-scale circulation but also helps sustain the climate differences between the Northern and Southern Hemispheres in the present-day climate. The team’s findings have broader implications for understanding ocean circulation–climate feedbacks and may provide insights into past climates and other planetary environments.
Looking ahead, the research team sees the important next step is to further quantify how individual components of ocean bathymetry and continental geometry regulate ocean circulation and climate. “Ultimately, we hope to better understand how ocean bathymetry interacts with other components of the Earth system to shape the global climate,” said Wang.
The research team includes Peixi Wang, Yihan Zhang, Song Yang, and Xiaoming Hu from Sun Yat-sen University; Zhenning Li from Hong Kong University of Science and Technology; and Qianyi Yu from Fudan University.
This research was funded by the National Natural Science Foundation of China.
Ocean-Land-Atmosphere Research
Computational simulation/modeling
Not applicable
Role of Oceanic Topography in Earth’s Climate: Insights from Aquaplanet Simulations with Bathymetry
25-Aug-2026
No conflicts of interest to declare.