The world’s oceans have played an important role in sequestering atmospheric carbon dioxide through solubility and the action of algae. Fixation of atmospheric carbon dioxide by photoautotrophic algal cultures has the potential to diminish the release of carbon dioxide into the atmosphere, thereby helping to alleviate the trend toward global warming. This work investigates the role of algae in controlling the level of atmospheric carbon dioxide. Partial Rank Correlation Coefficients (PRCCs) technique is used to address how the concentration of atmospheric carbon dioxide is affected by changes in a specific parameter disregarding the uncertainty over the rest of the model parameters. Parameters related to algal growth are shown to significantly reduce the level of atmospheric CO₂. Further, we explore the dynamics of nonautonomous system by incorporating the seasonal variations of some ecologically important model parameters. Our nonautonomous system exhibits globally attractive positive periodic solution, and also the appearance of double periodic solution is observed. Moreover, by letting the seasonally forced parameters as almost periodic functions of time, we show almost periodic behavior of the system. Our findings suggest that the policy makers should focus on continuous addition of nutrients in the ocean to accelerate the algal growth thereby reducing the level of carbon dioxide in the atmosphere.

中文翻译：

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评估藻类对大气二氧化碳减排影响的非自主数学模型

世界海洋通过溶解性和藻类的作用在隔离大气中的二氧化碳方面发挥了重要作用。通过光合自养藻类培养物固定大气中的二氧化碳有可能减少二氧化碳释放到大气中，从而有助于缓解全球变暖的趋势。这项工作调查了藻类在控制大气二氧化碳水平中的作用。偏秩相关系数 (PRCC) 技术用于解决大气二氧化碳浓度如何受到特定参数变化的影响，而忽略其余模型参数的不确定性。显示与藻类生长相关的参数可显着降低大气 CO _2水平. 此外，我们通过结合一些生态重要模型参数的季节变化来探索非自治系统的动力学。我们的非自治系统表现出具有全局吸引力的正周期解，并且还观察到了双周期解的出现。此外，通过让季节性强制参数作为时间的几乎周期性函数，我们展示了系统的几乎周期性行为。我们的研究结果表明，政策制定者应专注于在海洋中持续添加营养物质以加速藻类生长，从而降低大气中的二氧化碳水平。