Estimates of Anthropogenic CO2 Uptake in a Global Ocean Model

• Published in: Advances in atmospheric sciences Vol. 26; no. 2; pp. 265 - 274
• Main Author: 徐永福 李阳春
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science Press 01.03.2009; Springer Nature B.V
• Subjects: Anthropogenic factors; Atmospheric Sciences; Carbon dioxide; Distribution patterns; Earth and Environmental Science; Earth Sciences; Geophysics/Geodesy; Meteorology; Ocean circulation; Sea ice; Vertical distribution; Water circulation; 二氧化碳溶解; 全球海洋; 垂直分布格局; 模型生成; 海洋模式; 海洋环流模式; 碳吸收; anthropogenic CO; ocean general circulation model; oceanic uptake; ocean storage
• ISSN: 0256-1530; 1861-9533
• DOI: 10.1007/s00376-009-0265-z

A global ocean general circulation model （L30T63） is employed to study the uptake and distribution of anthropogenic CO2 in the ocean. A subgrid-scale mixing scheme called GM90 is used in the model. There are two main GM90 parameters including isopycnal diffusivity and skew （thickness） diffusivity. Sensitivities of the ocean circulation and the redistribution of dissolved anthropogenic CO2 to these two parameters are examined. Two runs estimate the global oceanic anthropogenic CO2 uptake to be 1.64 and 1.73 Pg C yr^-1 for the 1990s, and that the global ocean contained 86.8 and 92.7 Pg C of anthropogenic CO2 at the end of 1994, respectively. Both the total inventory and uptake from our model are smaller than the data-based estimates. In this presentation, the vertical distributions of anthropogenic CO2 at three meridional sections are discussed and compared with the available data-based estimates. The inventory in the individual basins is also calculated. Use of large isopycnal diffusivity can generally improve the simulated results, including the exchange flux, the vertical distribution patterns, inventory, storage, etc. In terms of comparison of the vertical distributions and column inventory, we find that the total inventory in the Pacific Ocean obtained from our model is in good agreement with the data-based estimate, but a large difference exists in the Atlantic Ocean, particularly in the South Atlantic. The main reasons are weak vertical mixing and that our model generates small exchange fluxes of anthropogenic CO2 in the Southern Ocean. Improvement in the simulation of the vertical transport and sea ice in the Southern Ocean is important in future work.