RAPID: Fingerprinting new water-carbon interactions in the Arctic: Isotopic measurements through the Northwest Passage and in Baffin Bay

北极的碳和水循环正在发生根本性的变化，因为北极正在经历一整套新的条件。这种重构的核心是北极迅速变暖、海冰减少、大气和海洋环流模式的改变、降水增加、永久冻土融化以及格陵兰冰盖和其他山地冰川和冰盖的加速融化。这些变化同时导致了北极海域的新鲜和北极大气的湿润，因为以前被冰覆盖的海洋蒸发了更多的水分。与此同时，河流的排放推动了北极海域的施肥，并通过将融化的永久冻土中的古老碳和古老营养物质带入峡湾、海湾和海洋，提高了海水的生产力。迫切需要监测和量化这些新的冰-海-陆-气相互作用，以了解整个北极地区碳和水循环变化的幅度和可变性。该项目利用了USCGC Healy破冰船2021年秋季的研究考察。该项目将使用连续的同位素指纹技术来描绘阿拉斯加西海岸、西北航道和巴芬湾的冰-海-陆-气相互作用之间的关键联系。该项目将连续测量海洋空气和海水的碳和水同位素，并在一些现场密集采样点进行测量。这些测量将能够量化地球化学模式，记录由不同程度的冰-海-陆-气相互作用驱动的更新、施肥、蒸发和生产力变化。这些数据将首次在如此大的尺度上与北极西部和中部跨越纬度约15度和经度超过100度的样带进行协调。该项目将：1)描绘陆冰淡水注入的强度，包括这些淡水羽流携带可能推动生产力提高和海洋碳交换的古老（永久冻土衍生）碳和营养物质的新来源的程度；2)量化北冰洋水蒸发和大气加湿的连通性和控制机制，这可能改变北极和中纬度地区的降水模式；3)通过大气二氧化碳和甲烷浓度，确定北冰洋海洋碳的不断增加或减少，从而影响海洋食物网、支持生存狩猎和气候变暖。该项目将为研究不断变化的大气、海洋、冰冻圈过程以及海洋和陆地生态系统的小组研究北极变化提供宝贵的贡献和数据。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 Arctic carbon and water cycles are undergoing fundamental changes as the Arctic experiences an entire suite of new conditions. At the core of this restructuring is rapid Arctic warming, the loss of sea ice, shifting atmospheric and ocean circulation patterns, increasing precipitation, permafrost thaw, and enhanced melt of the Greenland Ice Sheet and other mountain glaciers and ice caps. These changes have resulted in the simultaneous freshening of the Arctic seas and humidification of the Arctic atmosphere due to more evaporation from what was previously ice-covered ocean. Concurrently, riverine discharges are driving the fertilization of the Arctic seas and increasing ocean water productivity by carrying ancient carbon and old nutrients from thawed permafrost into the fjords, bays, and ocean. It is urgent to monitor and quantify these new ice-ocean-land-atmosphere interactions to understand the magnitude and variability of carbon and water cycle changes across the Arctic. This project capitalizes on an autumn 2021 research expedition of the USCGC Healy Icebreaker. The project will use continuous isotope fingerprinting to delineate key linkages between ice-ocean-land-atmosphere interactions along the west coast of Alaska, through the Northwest Passage and in Baffin Bay. The project will measure carbon and water isotopes of marine air and ocean water continuously with some spot intense sampling locations. These measurements will enable quantification of the geochemical patterns that record freshening, fertilization, evaporation, and productivity variations driven by differing degrees of ice-ocean-land-atmosphere interactions. These data will be the first of their kind in terms of coordination at this large scale with a transect spanning ~15 degrees of latitude and over 100 degrees of longitude in the western and central Arctic. This project will: 1) delineate the intensity of land-ice freshwater injections including the extent to which these freshwater plumes carry new sources of ancient (permafrost derived) carbon and nutrients that may drive productivity increases and ocean carbon exchange; 2) quantify the connectivity of and mechanisms controlling Arctic Ocean water evaporation and atmospheric humidification which may be altering precipitation patterns in the Arctic and in the mid-latitudes; and 3) determine ocean carbon gain or loss continuously across the Arctic seas with implications for marine food webs, support of subsistence hunting, and climate warming via atmospheric carbon dioxide and methane concentrations. This project will offer valuable contributions and data to studies of Arctic change by groups examining changing atmospheric, ocean, cryospheric processes, and marine and terrestrial ecosystems.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.