Collaborative Research: CAS-MNP: Sea ice-ocean exchange of Arctic microplastics: linking small scales to the large-scale system

微塑料被定义为小于5毫米的塑料碎片，是世界海洋中的一个巨大的垃圾问题。北冰洋虽然偏远，但也不能幸免;最近的研究发现，北极系统的所有组成部分都存在微塑料，包括漂浮的海冰覆盖层。虽然海洋微塑料无处不在，但极地海洋的物理特性，包括海冰，导致极地地区特有的影响。例如，微塑料可能会对气候产生影响，使通常明亮的白色海冰及其覆盖的积雪变暗，这将导致对阳光的吸收增加，从而导致变暖和融化。此外，海冰的存在影响了北极地区发现微塑料的地方，因为海冰和底层海洋运输微塑料的方式不同。本项目正在处理这两个进程。由于微塑料是一个全球性问题，对海洋生态系统的健康具有潜在影响，因此了解海冰和微塑料的相互作用方式对于制定未来应对这种污染的战略至关重要。在这个跨学科的研究项目中，实验室研究和数值模型正在一起使用，以在了解北极海冰和微塑料之间的相互作用方面取得进展。研究人员正在开发新的实验室技术，以了解海冰和海洋之间微塑料在吸收和释放过程中的交换，包括海洋凝胶对这一过程的影响。他们还测量了微塑料的光学特性对海冰质量平衡的影响。基于这些实验室见解，他们正在开发和测试参数化，以将微塑料纳入开源、社区海冰、海洋和气候模型。都是一维的（即，垂直列）和三维（即，完整的海冰/海洋耦合）模型正在从现有代码修改并运行。该奖项反映了NSF的法定使命，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。

Microplastics, defined as plastic pieces smaller than 5 millimeters, are a massive litter problem in the world’s oceans. The Arctic Ocean, while remote, is not immune; recent work has found microplastics in all components of the Arctic system, including within the floating sea ice cover. While marine microplastics are ubiquitous, the physical characteristics of the polar oceans, including sea ice, lead to effects unique to the polar regions. For example, microplastics may have an impact on climate by darkening the usually bright white sea ice and its overlying snow cover, which would result in an increase in the absorption of sunlight and thus in warming and melting. Furthermore, the presence of sea ice affects where microplastics are found within the Arctic, as sea ice and the underlying ocean transport microplastics differently. This project is addressing both these processes. As microplastics are a global problem with potential impact on the health of the marine ecosystem, understanding the way sea ice and microplastics interact is crucial for informing strategies to deal with this pollution in the future. In this interdisciplinary research project, laboratory studies and numerical models are being used together to make progress in understanding the interactions between Arctic sea ice and microplastics. The researchers are developing new laboratory techniques to understand the exchange of microplastics between sea ice and the ocean during uptake and release, including the effect of marine gels on this process. They are also measuring the effects of the optical properties of microplastics on the mass balance of sea ice. Based on those laboratory insights, they are developing and testing parameterizations for including microplastics in open-source, community sea ice, ocean, and climate models. Both one-dimensional (i.e., vertical column) and three-dimensional (i.e., full sea ice/ocean-coupled) models are being modified from existing code and run. Hindcast and future simulations are being performed to assess the impact of including microplastic ice-ocean exchange parameterizations on the large-scale distribution of microplastics in the Arctic Seas and their impact on climate.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.