International Journal of Marine Science, 2024, Vol.14, No.2, 51-56 http://www.aquapublisher.com/index.php/ijms 56 to a weaker ACC reducing water exchange in the surrounding seas, leading to lower local ocean temperatures and favoring ice sheet expansion. Conversely, during periods of strengthened ACC, the ice sheet tends to retract. This pattern suggests that the ACC plays an important role in regulating Antarctic climate and ice sheet dynamics. It is noteworthy that these long-term changes in ACC strength over the past few million years were not uniform but displayed significant turning points that matched Earth's orbital cycles. Particularly during the Mid-Pleistocene Transition (MPT), as Earth’s climate shifted from approximately 41 000-year glacial-interglacial cycles to about 100 000-year cycles, there was also a clear shift in ACC variability patterns. This may indicate that during the MPT, the ACC responded to a fundamental reorganization of deep ocean circulation and global ice volume changes. 3 Research Evaluation The outstanding contribution of this study lies in the high-precision geological records it provides and the detailed analysis of historical strength changes in the Antarctic Circumpolar Current (ACC). The fine interpretation of paleoclimatic data not only consolidates our understanding of the role of the ACC in the global climate system but also offers new insights into its function in the climate changes of the past few million years. Notably, the study highlights the direct correlation between ACC strength variations and Earth’s orbital cycles, revealing complex interactions between the ocean and atmosphere within the global climate system. Moreover, the interaction between the ACC and the Antarctic ice sheet is crucial for understanding the transitions of Earth's glacial-interglacial cycles, providing valuable historical references for predicting future climate changes. Overall, this research deepens our understanding of Earth's paleoclimatic mechanisms and offers critical calibration points for models simulating future climate changes. 4 Conclusion This study demonstrates the ACC as a dynamic system, whose variations are influenced by a combination of factors, including Earth’s orbital periodic changes, atmosphere-ocean interactions, and polar ice sheet dynamics. These changes of the ACC have profound implications for the global climate system. The results emphasize that future climate models and predictions must consider this complex natural variability of the ACC and its central role in the Earth system. The ACC is not only an indicator of past climate change but may also be a key factor in the stability of future climates. By understanding its past behavior patterns, we can better predict the likelihood and extent of future climate changes, thereby formulating more scientific strategies to address global climate changes. 5 Access the Full Text Lamy F., Winckler G., Arz H.W., Farmer J.R., Gottschalk J., Lembke-Jene L., et al., 2024, Five million years of antarctic circumpolar current strength variability, Nature, 627(8005): 789-796. https://rdcu.be/dDtoS Acknowledgments This research received funding from Consorci del Colls i Miralpeix Costes del Garraf, and ecosystem sampling and data acquisition were supported by the Promar Association (Vilanova i la Geltrú). The design and implementation of geode structures submerged in the study area were carried out by Litoral Consult. This project received valuable contributions from Sílvia Gili from Acció-Natura.
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