中国海洋碳循环生物地球化学过程研究的主要进展(1998-2002)

Advances in Biogeochemical Process Research on Marine Carbon Cycles in China(1998-2002)

阐述了1998-2002年期间中国海洋碳循环及其生物地球化学过程研究的3个主要进展部分:(1)海-气二氧化碳通量过程;(2)海水中碳及其生物地球化学循环;(3)入海河流流域土壤和沉积物在海洋碳循环中的作用。海洋与陆地容纳了近一半人类排放的二氧化碳,另外的50%被释放到大气中,海洋在缓和二氧化碳温室效应方面的作用不言而喻的。海洋储有的碳主要以无机碳的碳酸盐(CO32-)和碳酸氢盐(HCO3-)的形式存在。海洋生态系统通过生物泵的作用驱动大气CO2进入海洋,在表面混合层中,由于生物的光合作用,CO2不断被转化成有机碳和生物碳酸盐,并进一步从表层CO2向深层转移,形成了海洋碳循环的主要途径。海洋水体中碳循环过程受到河口与近海碳的形态、转化、分布、迁移和生物生产过程等影响,海洋生物泵明显影响着海洋对空气中CO2的容量。春季和冬季东中国海皆为大气二氧化碳的汇,夏季皆为二氧化碳的源,秋季渤海与北黄海为二氧化碳的汇,南黄海与东海是二氧化碳的源。入海河流流域土壤、非入海河流流域的土壤和海洋沉积物在碳的来源、分布、含量及其迁移循环中具有重要的作用。

In this paper, the main advances in the researches on marine carbon cycles and their biogeochemical processes in China during 1998-2002 are presented, and these researches include the airsea CO2 flux process, the carbon in seawater and its biogeochemical cycles and the functions of fluvial soil and sediment in marine carbon cycle. Ocean and land hold about half of CO2 discharged by human activities, and another half of CO2 is released into atmosphere, so ocean plays an important role in mitigating the greenhouse effect of CO2. Carbon stored in the ocean exists mainly in the forms of CO32－ and HCO3－. CO2 in the atmosphere is driven into ocean by the bioloical pump in marine ecosystem, then changed into organic carbon and biological carbonates by biological photosynthesis in the mixed layer, and is further transferred from surface to deep layer, which forms the main approach for marine carbon cycle. The carbon cycling process is affected by the form, change distribution, transfer and biological production process of estuarine and inshore carbons, and the marine biological pump significantly affects the ocean capacity for absorping CO2 in the atmosphere. The eastern China Seas are all the sink of atmospheric CO2 in spring and winter, and the source in summer. In autumn, the Bohai Sea and the northern Yellow Sea are the sink of atmospheric CO2, and the southern Yellow Sea and the East China Sea are the source. Marine sediments and soils from the valley of river flowing into the sea and the valley of river not flowing into the sea play an important role in carbon origin, distribution, content, transfer and recycle.