西太平洋最小含氧带对基于生物泵传输效率的生源要素循环的影响

以碳的垂直输送为主要特征的生物泵是海洋碳循环的关键过程之一，也是连接大气圈、水圈和生物圈之间碳循环的纽带。最小含氧带的存在显著改变了颗粒有机碳的矿化速率，但目前尚未确定最小含氧带的发育程度与生物泵传输效率的关系，其对以碳为代表的生源要素循环所造成的后果和机制仍不明了。本项目将在研究西太平洋最小含氧带形成机制的基础上，探讨西太平洋最小含氧带的发育及其对全球变暖的响应；测定最小含氧带上部、内部和下部的颗粒物沉降通量，估算西太平洋生物泵传递效率；分析西太平洋颗粒物中碳、氮同位素、氨基酸、氨基糖或其它新型的特征标志物，构建新的指标体系以区分沉降颗粒物中上层水体沉降和原位生产的相对贡献，解析最小含氧带下部水层中颗粒物的来源；探讨最小含氧带内、外颗粒物的降解过程和生源要素释放特征，明确最小含氧带对西太平洋生物泵传递效率和生源要素循环的影响，为深入认识大洋海水溶解氧逸失对生源要素循环的影响提供理论依据。

The biological pump featuring the vertical transport of carbon is one of the key processes of the marine carbon cycle, which is the link of carbon cycle among the atmosphere, the hydrosphere and the biosphere. The oxygen minimum zone has significantly changed the mineralization rate of particulate organic carbon, but the relationship between the development of the minimum oxygen zone and the transfer efficiency of the biological pump has not yet been clear, and its effects and mechanism on the cycle of biogenic elements represented by carbon remain unclear. Based on the study of the formation mechanism of the oxygen minimum zones in the Western Pacific, this project will explore the distribution of the oxygen minimum zones and its response to global warming. The Vertical fluxes of particulate matter in the above, in and below the oxygen minimum zone were measured to estimate the transport efficiency of biological pumps in the Western Pacific. Based on the measure of carbon and nitrogen isotopes, amino acids, amino sugars or other new featured markers in the particulate matter from the Western Pacific, a new indicator system, which can distinguish the relative contributions of particulate matters deposited from the upper water column or generated in-situ, will be set up. And then the source of particulate matter in the water below the oxygen minimum zone will be analyzed. The degradation process and the release of biogenic elements of particulate matter inside and outside the oxygen minimum zone will be discussed, and its effect on the transport efficiency of biological pumps and the cycle of biogenic elements will be quantified in the Western Pacific. The results of the project will provide the theoretical basis for further understanding the effect of dissolved oxygen escape on the biogenic elements cycle in the ocean.