Discerning Boron to Salinity Ratios in Arctic Marginal Ice Zones - BAMZ

北冰洋在调节地球气候方面发挥着重要作用。虽然它只占海洋总面积的3%，但它占据了我们每年排放到大气中的二氧化碳的10%。尽管北极一直有永久的冰盖，但它的面积正在缩小，到2040年，永久的夏季冰盖将消失。这意味着每年融化的冰量将会增加，人们对冰川融化将如何改变北极地表水化学知之甚少。这项研究将对北冰洋的冰、雪和卤水进行采样，以绘制其在北极东部的化学剖面图，目的是随着北极气候的变化对未来的北极环境做出更好的预测。主要关注的是在开阔海域保持恒定比率的硼和盐度的冰剖面，但在盐度低于30g/kg的边缘冰区，这一比率可能会发生变化，并因融化而变得新鲜。这个项目还将创造一些课程，展示我们如何使用化学来做这项工作和了解气候。这个项目加入了2023年5月在I/B Oden进行的大气河流和海冰融化开始(ARTofMELT)考察，在边缘冰带(MIZ)进行采样，包括冰芯和盐水。其目标是辨别这些独特系统的硼盐比，以及它们对总碱度和大气二氧化碳吸收的影响。目标包括：1)确定北极海冰和卤水中的B/盐度(B/S)比值；2)确定北极海冰和卤水中的碳酸盐体系参数；3)比较上述参数在年冰和多年冰和卤水中的分布；4)评估在特定冰站融冰过程中这些参数的变化；以及5)评估冰川融化对冰川附近融化水中B/S比值和总碱度的影响。智力价值：这项研究为生物地球化学、物理海洋学、气象学和气候变化研究做出了贡献。B/S比值的结果将为极地地区的总碱度分析提供重要的校正，并在未来的北极二氧化碳吸收估计和模拟工作中改进参数化。最值得注意的是，这项研究将首次提供该地区年度冰中的硼盐度分布，以及任何地区的第一个多年冰分布。此外，还将生成其他生物地球化学相关参数的冰和盐水剖面。预计这项研究的结果将为未来北极变暖和北极二氧化碳吸收的生物地球化学提供新的见解。更广泛的影响：将根据研究中使用的化学概念(平衡常数、酸度常数等)生成十个配对视频(来自游轮)和教案，以高中和本科生为目标化学学生。巡游结束后，这些内容将张贴在项目网页上，并与PBS学习媒体和其他教育资源平台分享。所有课程都将介绍北极冰川融化的主题。研究人员还将继续与高级插图学生合作，为更广泛的公众创作以北极海冰消退为主题的项目(书籍、海报、短片)。该项目将为两名女性研究生创造机会，其中一人将有机会在韩国进行硼分析方面的国际合作，至少四名来自少数群体的本科生将通过REU项目和康涅狄格大学的FirstGen项目获得机会。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 Arctic Ocean has an important role in regulating earth’s climate. Though it is only 3% of the total ocean it takes up 10% of the carbon dioxide we add to the atmosphere every year. Though the Arctic has always had a permanent ice cap, it is shrinking in size and by the year 2040 the permanent summer ice cap will be gone. This implies that there will be an increased intensity in the amount of ice that melts each year and there is little known about how the melting ice will alter Arctic surface water chemistry. This study will sample Arctic Sea ice, snow, and brine to map its chemistry profiles in the eastern Arctic with the goal of making better predictions in the future Arctic environment as the Arctic climate changes. The main focus is on the ice profiles of boron and salinity which have a constant ratio in the open ocean, but this ratio may shift in the marginal ice zone at salinities that are less than 30 g/kg and are freshened by melt. This project will also create lessons that show how we use chemistry to do this work and understand climate.This project joins the Atmospheric rivers and the onset of sea ice melt (ARTofMELT) Expedition on the I/B Oden in May June 2023 to conduct sampling in the marginal ice zone (MIZ), including ice cores and brine. The goal is to discern the boron to salinity ratios of these unique systems and their impact on total alkalinity and uptake of atmospheric CO2. The objectives include; 1) to determine the boron to salinity (B/S) ratios in Arctic sea-ice and brine, 2) to determine the carbonate system parameters in Arctic sea-ice and brine, 3) to compare the profiles of all above parameters in annual vs multi-year ice and brine, 4) to evaluate changes in these parameters over the ice-melt process at a given ice station, and 5) to assess the impact on B/S ratios and total alkalinity in adjacent meltwaters of the MIZ. Intellectual Merit: This study contributes to biogeochemical, physical oceanographic, meteorological and climate change research. The results of the B/S ratios will provide important corrections to total alkalinity analyses in polar regions and improve parameterizations in future Arctic CO2 uptake estimates and modeling efforts. Most notably, this study will provide the first ever boron to salinity profiles in annual ice in this region and the first multiyear ice profiles in any region. In addition, ice and brine profiles of other biogeochemically relevant parameters will be generated. It is expected that the results of this study will provide new insights on the future biogeochemistry of the warming Arctic and Arctic CO2 uptake. Broader Impacts: Ten paired videos (from the cruise) and lesson plans will be generated that target high school and undergraduate chemistry students based on chemical concepts used in this research (equilibrium constants, acidity constants, etc.). Following the cruise these will be posted on the project webpage and shared with PBS Learning Media and other educational resource platforms. All lessons will introduce the theme of Arctic ice loss. Researchers will also continue to work with senior illustration students to create Arctic sea ice retreat themed projects (books, posters, short animations) for the broader public. This project will create opportunities for two female graduate students, one of which will have the opportunity for international collaboration in Boron analysis in Korea, and at least four undergraduate students from minority groups through an REU program and the FirstGen program at University of Connecticut.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.