末次冰消期太平洋地区大洋通风研究及展望

Research and prospect of ventilation in the last deglaciation in the Pacific Ocean

作为对气候变化敏感的温室气体,CO2的变化和气候变化密切相关。末次冰消期(18.0~11.7 ka)以来CO2含量的大幅波动和大洋环流格局变化密切相关,尽管北大西洋和南大洋环流格局变化显著,但对于太平洋地区环流格局变化及其如何响应CO2含量变化的波动尚无明确定论,合理阐述太平洋地区通风演变历史及其机制将有助于理解不同气候系统之间的相互作用机制。本文综述了末次冰消期以来太平洋地区大洋通风的研究现状,认为在冰消期冷期北太平洋主要被活跃的北太平洋中层水占据,而南太平洋则被携带有亏损碳库特征的南极中层水所占据,在冰消期暖期则恢复到现在的气候状态,这样的变化和大洋环流格局及CO2浓度的变化密切相关。冰消期南北源水团的相互竞争可能主导着太平洋对全球气候的响应。另外,大洋表层储库年龄及深层水研究的缺乏极大地限制着当前太平洋地区大洋通风的研究。而不同深度的水团尤其是中层水的综合演化亟须建立。

As a sensitive climate indicator,the variability of CO2 is tightly related to climate change.The fluctuation of greenhouse gas during the last deglaciation(18.0~11.7 ka)was correlated with the change of oceanic circular pattern.However,it is still unclear how the oceanic circular pattern changed in the Pacific Ocean and how they respond to the variability of CO2 concentration in the last deglaciation,though there is significant change of circular pattern in the north Atlantic and southern ocean.Reasonable illustration about the ventilation history and mechanism will be contributed to understanding the interaction between different climate systems.This paper summarizes the research status of the last deglaciation oceanic ventilation in the Pacific Ocean.It is concluded that B-P age method,Projection age method,B-A age method,U series dating and 14C method can approximately calculate the ventilation age.And also,it is believed that in the cold period of the last deglaciation the North Pacific Ocean was mainly occupied by the vigorous North Pacific intermediate water,whereas the South Pacific Ocean was occupied by the Antarctic intermediate water carrying the characteristics of depleted carbon pool,and they returned to its current climate during the warm period.The existence of deeper north Pacific intermediate water and 14C depleted Antarctic intermediate water was influenced by the climate change,which in turn affect regional climate,such as pH,biological productivity,redox.Competition between the North and South Source Water mass during the deglaciation may dominate the response to the global climate of the pacific.However,the lacking research of the marine surface reservoirs and the deepwater has quite limited the current study of oceanic ventilation in the Pacific Ocean,and the comprehensive evolution of intermediate water is urgently needed.