Decadal trends in oceanic anthropogenic CO2 from the CLIVAR and GO-SHIP d13C datasets and in an ocean biogeochemistry model

海洋吸收了人类排放的大约三分之一的化石燃料二氧化碳(CO2)，减缓了二氧化碳的积累及其在大气中对热能的捕获。这项研究旨在提高我们对当海洋环流对气候持续变化做出反应时，海洋对二氧化碳的吸收将如何变化的理解。研究人员将使用对海水和大气样本的碳同位素比率(13C/12C)的观测，作为一种高信噪比方法来确定海-气转移速率和化石燃料二氧化碳在海洋内部的储存。此外，一个最先进的海洋碳循环模型将被用来验证该模型的海气交换率和上层海洋化石燃料二氧化碳的储存。13CO2提供的补充信息将在用于预测未来气候变化的模型中确立关于海洋-大气和生物圈-大气C交换的重要基准。结果将通过华盛顿大学的气候变化计划纳入一个外联计划，教育公众关于人类活动和气候对海洋、大气和地球的影响。一名博士后将作为该项目的一部分得到支持和培训。为了更好地了解控制海洋中人为二氧化碳(CO2)信号演变的过程，我们将利用溶解无机13C(DIC13)的两个特征，将其与DIC区分开来。首先，DIC13的海-气平衡时间延长了10倍，在所有盆地中产生了可在十年时间尺度上分辨的、受良好约束的海-气13CO2通量。其次，人为DIC13在海洋中的积累是可以量化的，比人为DIC本身对噪声有更好的信号。WOCE、CLIVAR和GO-SHIP提供的海洋Del13C和DIC数据提供了仅凭观测就有机会量化海洋中人为DIC和DIC13信号在区域和全球范围内的演变和传输的机会。将人为的DIC和DIC13扰动应用到一个由年际变化的风驱动的海洋模式中，将产生DIC和DIC13演变的模拟，我们将与观测结果进行比较，帮助确定导致这种演变速度年代际变化的可能过程。结合观测和模式分析追踪十年来的DIC13和DIC扰动，旨在通过吸收和储存人为二氧化碳，提高我们对海洋在调节气候方面的重要作用的洞察。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The ocean has absorbed about a third of the fossil fuel carbon dioxide (CO2) that humans have emitted, slowing the accumulation of CO2 and its associated trapping of thermal energy in the atmosphere. The research aims to improve our understanding of how this ocean uptake of CO2 will change when ocean circulation responds to continuing changes in climate. Researchers will use observations of the isotopic ratio of carbon (13C/12C) of seawater and atmospheric samples, as a high signal/noise method to determine air-sea transfer rates and storage in the ocean interior of fossil-fuel CO2. Also, a state-of the art ocean C-cycling model will be used to validate the model's air-sea exchange rates and upper ocean storage of fossil-fuel CO2. The additional information provided by 13CO2 will establish important benchmarks on ocean-atmosphere and biosphere-atmosphere C exchanges in models used for forecasting future changes in climate. Results would be incorporated into an outreach program through the University of Washington's Program on Climate Change to educate the public on the impact of human activity and climate on the ocean, atmosphere, and earth. One postdoc would be supported and trained as part of this project.To better understand the processes that control the evolution of the anthropogenic carbon dioxide (CO2) signal in the ocean, we will utilize two characteristics of dissolved inorganic 13Carbon (DIC13) that distinguish it from DIC. First, the 10x longer air-sea equilibration time for DIC13 yields a well-constrained air-sea 13CO2 flux in all basins that is resolvable on decadal time scales. Second, the anthropogenic DIC13 accumulation in the ocean is quantifiable to better signal to noise than anthropogenic DIC itself. The availability of ocean del13C and DIC data from WOCE, CLIVAR and GO-SHIP provide the opportunity to quantify, based on observations alone, the evolution and transports of the anthropogenic DIC and DIC13 signal on regional and global scales in the ocean. Implementation of the anthropogenic DIC and DIC13 perturbations into an ocean model, driven by interannually varying winds, will yield simulations of the DIC and DIC13 evolution that we will compare to observations, helping to identify likely processes causing interdecadal shifts in the rate of this evolution. The combination of observations and model analysis tracking the decadal DIC13 and DIC perturbations are designed to improve our insight into the ocean's important role in modulating climate by taking up and storing anthropogenic CO2.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.