Diurnal variations of surface seawater pCO2 in contrasting coastal environments
Diurnal variations of surface seawater pCO2 in contrasting coastal environments
复制标题
对比沿海环境中表层海水 pCO2 的日变化
DOI：
10.4319/lo.2009.54.3.0735
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发表时间：
2009-05-01
影响因子：
4.5
通讯作者：
Chen, Chen-Tung Arthur
中科院分区：
文献类型：
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作者：
Dai, Minhan;Lu, Zhongming;Chen, Chen-Tung Arthur
从厦门湾、深沪湾和台湾海峡西南部的近岸和近岸环境，到盆地近海和南中国海北坡的近海站点，以及南海中部西沙群岛的珊瑚礁系统，我们研究了南海中国附近一套近海海洋环境系统表层海水二氧化碳分压(二氧化碳分压)的日变化。表层二氧化碳分压日变化显著，近海和贫营养水域的表层二氧化碳分压为1.0~1.6Pa(10-16µatm)，台湾海峡为4.1Pa，厦门湾和深湖湾为5.1~15.2Pa.西沙群岛珊瑚礁系统最高可达60.8Pa.调节这些二氧化碳日变化的过程是温度、潮汐或海流以及生物控制。温度是寡养区二氧化碳日变化的主要驱动因素，而潮汐效应在近岸很重要。在珊瑚礁系统中，生物新陈代谢主导了变异性。日变化可能对估算海-气二氧化碳通量具有潜在的重要意义，这可能导致南海近海站点Cm−2 d−1的不确定度为±0.48~0.77mmolCm。这种不确定性在近岸环境中更大。
We examined diurnal variations of surface seawater pCO2 (partial pressure of CO2) in a suite of coastal marine environmental systems in the vicinity of the South China Sea (SCS) from inshore and nearshore settings in Xiamen Bay, Shenhu Bay, and the southwestern Taiwan Strait, to offshore sites in the basin and on the slope of the northern South China Sea as well as in a coral reef system at Xisha Islands in the middle of the SCS. There were significant diurnal changes of surface pCO2, ranging from 1.0 Pa to 1.6 Pa (10‐16 µatm) in the offshore and oligotrophic sites, ~4.1 Pa in the Taiwan Strait, 5.1‐15.2 Pa in Xiamen Bay and Shenhu Bay, to as high as 60.8 Pa in the coral reef system at Xisha Islands. Processes that modulate these pCO2 diurnal variations were temperature, tide or current, and biological controls. Temperature was a major driver of the pCO2 diurnal variability in the oligotrophic regions, while tidal effects were important in the nearshore. In the coral reef system, biological metabolism dominated variability. Diurnal variability could have a potentially important implication on the estimate of air‐sea CO2 fluxes, which may result in an uncertainty of ±0.48‐0.77 mmol C m−2 d−1 for the offshore sites in the SCS. Such uncertainties were larger in nearshore settings.