Modern observations suggest that carbon dioxide (CO₂) emissions from human activities have altered surface albedo, contributing to continued warming in the Arctic Ocean. However, existing studies using high-resolution climate models indicate that this ongoing warming is not solely linked to changes in the Earth’s surface reflectivity; it is also closely associated with the transport of water vapor from the Pacific Ocean to the Arctic. Researchers have shown that the transport of heat and moisture from the low latitudes of the North Pacific to the poles significantly, impacting Arctic climate and sea ice distribution. The influence of ocean heat and moisture transport through the Bering Strait on Arctic warming may be greater than that of CO₂ emissions, although long-term geological data to support this claim is lacking.

The Earth's orbit is not constant, but changes periodically, which in turn affects the latitude and seasonal distribution of solar radiation on the Earth's surface. The cycles of this climate change are mainly 41,000 years (obliquity), 23,000 years (precession), and 100,000 years and 413,000 years (eccentricity). Among them, the radiation in high-latitude areas is greatly affected by the slope, while the precession is strongest in mid- and low-latitude areas. For example, the monsoon rainfall is controlled by the precession cycle (20,000 years), which have an important impact on the early low-latitude African arid areas in the past and play a key role in early human migration and evolution. However, whether the monsoon rainfall controlled by the precession of the equinoxes will also affect the ice sheet climate system in high-latitude areas needs to be further clarified.

To address this significant scientific question, we focused on the Bering Sea region, a key area linking the Pacific Ocean and the Arctic. This area facilitates the transport of Pacific water vapor to the Arctic Ocean through the Bering Strait. A breakthrough of this study is identifying a suitable alternative indicator for moisture changes; based on this, the team aims to investigate the primary control cycles of water vapor variation in this area and the dynamic processes involved in the transport of Pacific water vapor. Therefore, examining the high-resolution moisture records on an orbital timescale in the Bering Sea region is essential for understanding the dynamics of Pacific water vapor transport.

Using the sediment samples of the U1342 station obtained in the Bowers Ridge area of ​​the Bering Sea during the 2013 International Ocean Drilling Expedition 323, the humidity record of the Bering Sea region over the past 400,000 years was reconstructed through multi-proxies methods such as clay minerals and rock magnetism. Through the 300,000-year continuous simulation of the global climate model, the dynamic analysis of the heat and moisture transport from the North Pacific subtropical gyre to the poles was proposed, and the dynamic model of the North Pacific high-low latitude water vapor circulation driven by precession was proposed. This work has made important innovations in emphasizing the high-to-low latitude water vapor transfer process driven by precession under the regulation of long eccentricity; model analysis depicts the thermodynamic and kinetic processes of heat and water vapor transfer from the low-latitude Pacific to the polar regions, further emphasizing water vapor transfer as a prerequisite for ice sheet growth and highlighting the important role of low-latitude drive in the late Pleistocene ice expansion pattern.

The study found that the poleward heat transfer in the North Pacific will have an important impact on the retreat of Arctic sea ice under the background of future climate warming. At the same time, due to the intensification of the "Arctic amplification" effect, may have a wide-ranging impact on the changes in global climate patterns and the destruction of ecosystems. This not only provides a new perspective for revealing Arctic climate change but also provides important inspiration for the interaction between the ocean and climate systems under the background of global climate warming.