热带海洋生产力:现代过程与地质记录

Tropical Marine Productivity: The Modern Progress and Paleoproductivity Records

首先综述了现代热带海洋生产力的分类与影响因素,然后讨论了古生产力替代性指标的分类与各类方法的优点与局限性。在此基础上,通过收集整理前人使用不同替代性指标对热带海洋古生产力重建的结果,讨论了热带海洋古生产力记录的特征、周期性与驱动机制。发现从末次冰期到全新世热带海洋古生产力在冰期时明显偏高,但冰期生产力高间冰期生产力低的规律并不一直适用,MIS 22前后西太平洋初级生产力在冰期—间冰期的变化发生反转。热带海洋古生产力的周期性也与高纬海区显著不同,岁差和斜率的信号更为显著。还存在约30 ka等不同轨道周期叠加之后形成的周期。颗石藻计算的海洋生产力可能存在约400 ka周期,这对全球碳同位素的影响有待深入研究。

The classification and influencing factors of modern marine productivity were reviewed at the beginning. We discussed the pros and cons of different paleoproductivity proxies. Based on these discussions,we collected paleoproductivity reconstructions in tropical marine from previous studies and focus on the glacial-interglacial features,periodicity and forcing mechanisms of tropical marine productivity. We found that the productivity in most tropical sites decreased from MIS 2 to MIS 1. The productivity was not always higher in glacial： The glacial-interglacial pattern of productivity turned at MIS 22 in western Pacific. There were remarkable differences between tropical productivity and high latitude productivity. The precession and obliquity bands were more significant in tropical productivity and ~ 30 ka cycles caused by the superimposing of different orbital cycles were common in tropical.The coccolith based productivity seemed to have a quasiperiod of 400 ka and more researches are needed to discover the relationship between productivity and global13 C in this band.