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捕获热能的速度。这项研究旨在提高我们对海洋环流对气候持续变化的反应时海洋对二氧化碳的吸收将如何变化的理解。研究人员将利用对海水和大气样本的碳同位素比率（13C/12C）的观测，作为一种高信号/噪声方法来确定空气-海洋传输速率和海洋内部化石燃料二氧化碳的储存。此外，一个最先进的海洋碳循环模型将用于验证该模型的海气交换率和上层海洋储存的化石燃料二氧化碳。13CO2提供的额外信息将在用于预测未来气候变化的模式中建立海洋-大气和生物圈-大气C交换的重要基准。研究结果将通过华盛顿大学气候变化项目纳入一项外展计划，向公众宣传人类活动和气候对海洋、大气和地球的影响。作为该项目的一部分，将支持和培训一名博士后。为了更好地理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碳（DIC13）的两个特征来区分它与DIC。首先，DIC13的海气平衡时间延长了10倍，因此所有盆地的海气13CO2通量都受到了很好的约束，可以在年代际时间尺度上进行解析。其次，与人为DIC本身相比，海洋中人为DIC13的积累是可量化的，可以更好地向噪声发出信号。WOCE、CLIVAR和GO-SHIP提供的海洋del13C和DIC数据的可用性，提供了仅根据观测就量化海洋中区域和全球尺度上人为DIC和DIC13信号的演变和传输的机会。在年际变化风驱动的海洋模式中实施人为DIC和DIC13扰动，将产生DIC和DIC13演变的模拟，我们将与观测结果进行比较，从而帮助确定导致这种演变速度的年代际变化的可能过程。观测和模式分析相结合，跟踪DIC13和DIC的年代际扰动，旨在提高我们对海洋通过吸收和储存人为二氧化碳来调节气候的重要作用的认识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.