南大洋海-气CO_2通量研究进展

ADVANCES IN THE STUDY OF AIR-SEA CO_2 FLUXES IN THE SOUTHERN OCEAN

南大洋是全球最重要的CO2汇区之一。准确估算南大洋及其各海区的海-气CO2通量,是全球碳循环研究的重要内容,其对预测和评估未来南大洋在全球变暖日益加剧的背景下发挥的作用有重要意义。但由于南大洋广阔的海域,恶劣的气候条件、自身复杂的水文物理及地球化学过程等原因,目前对南大洋的CO2通量的评估不一而足,存在较大差异和不确定性。本文讨论了南大洋海-气CO2通量的估算方法和各个海域海-气CO2通量研究的最新进展,并分析了南大洋海-气CO2通量的控制及影响因素。目前对南大洋的年吸收量估计为大约在0.1—0.6PgCyr-1,同时,所有的研究都表明,其存在极大的年度变化性。并且,由于各个海区受到生物、物理和水文等各方面的影响,表层海水CO2分压(pCO2)表现出极大的时空变异性。

Southern Ocean is the most important CO2 sink in the world. Evaluating the air-sea CO2 fluxes in each sea area of Southern Ocean precisely is an important content of research on global carbon cycle, and also is significant to predict and evaluate the role of Southern Ocean while global warming is getting worse and worse. However, due to expansive area, execrable climate and complex hydrological and geochemical processes in the Southern Ocean , there are rather highly discrepancy and uncertainty in evaluating the Southern Ocean＇ s CO2 fluxes at present. The paper mainly discusses the method of evaluating air-sea CO2 fluxes in the Southern Ocean, the late advances of air-sea CO2 fluxes in each sea area, and analyzes the controlling and influ- encing factors of air-sea CO2 fluxes. The annual CO2 uptake of Southern Ocean is about 0.1-- 0.6 Pg C ~ yr-1, meanwhile, all the studies indicate that there is huge variability in annual se- questration. Because each sea area is influenced by biological, physical and hydrological processes, and the pCO2 has high spatio-temporal variability.