Aspects of dissolved inorganic carbon dynamics in the upwelling system off the Galician coast

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• 作者：Borges ; Alberto V. ; Frankignoulle ; Michel
• 关键词：pCO₂ ; Upwelling ; Continental margin exchange ; Galician coast
• 刊名：Journal of Marine Systems
• 出版年：2002
• 出版时间：April, 2002
• 年：2002
• 卷：32
• 期：1-3
• 页码：181-198
• 全文大小：558 K

文摘

In the present paper, we report data on the partial pressure of CO₂ (pCO₂) in surface seawater off the Galician coast, obtained during four cruises carried out in summer (upwelling conditions). Over the continental shelf, two processes that have opposite effects control pCO₂ in surface waters: (a) the input from upwelling of deep cold water with high CO₂ content that causes oversaturation of CO₂ and (b) primary production that tends to decrease pCO₂. In offshore waters, the distribution of pCO₂ is mainly controlled by temperature change. In two distinct hydrographic coastal regions, the Rías Baixas area (RBA) and the Cape Finisterre area (CFA), the patterns of the distribution of pCO₂ are complex but, in the Rías Baixas area, the averaged pCO₂ values are systematically lower and temperature values higher. These differences between the two hydrographic regions are mainly related to the combination of outwelling from the Rías and the width of the continental shelf. In the Rías Baixas area, outwelling affects significantly the adjacent inner continental shelf but to a much lesser extent the outer continental shelf. In the Cape Finisterre area, the continental shelf is narrower and the ratio between the surface area of the shelf to the length of the shelf break is lower, inducing during an upwelling event, lower temperature and higher pCO₂ values in surface waters than in the Rías Baixas area.