From the Ocean to the Air: Aerosol-cloud Interactions during the Onset of Arctic Sea Ice Melt

由于北极变暖的速度至少是全球变暖速度的四倍，云等特征会影响地表温度。这一点很重要，因为预计北极未来将变得更加多云，北极的温度变化会影响全球天气和气候。然而，我们对北极云的理解仍然高度不确定，部分原因是对帮助它们形成的空气传播颗粒（称为“气溶胶”）的理解很差，特别是在春季海冰和积雪开始融化时。对于这个项目，我们的目标是提高我们对春季融化期间北极气溶胶及其如何影响云的理解。我们计划通过国际合作和参与2023年5月至6月在北冰洋由瑞典领导的ARTofMELT探险来实现这一目标。这项工作涉及云形成气溶胶的观测和建模，旨在测试我们关于这些气溶胶来自何处以及它们如何帮助云形成的目标假设。通过检验我们的假设，将获得更好的了解春季海冰融化期间气溶胶对北极云层的影响。更广泛地说，该项目提供了一个独特的机会，以解决地球不断变化的大气对“新北极”海冰的影响，这一目标只能通过跨学科和国际合作才能成功实现。该项目团队包括4名女性和6名早期职业研究人员，并与两个非营利组织合作，通过现场虚拟活动和ARTofMELT探险博客与全球K-12教室交流学习目标，计划和成果。预计还将举办外联研讨会来传达我们的研究结果，并更广泛地向公众介绍北极快速变化的各个方面。由于北极变暖的速度至少是全球变暖速度的四倍，云的反馈将对地表能量收支产生复合影响，从而影响区域和全球天气和气候。然而，我们对北极云的理解仍然高度不确定，部分原因是对帮助它们形成的空气传播颗粒（称为“气溶胶”）的理解很差，特别是在春季海冰和积雪开始融化时。对于这个项目，我们的首要目标是提高我们对春季融化期间北极地区气溶胶来源和云影响的理解。我们计划在2023年5月至6月期间通过国际合作和参与瑞典领导的ARTofMELT在北冰洋的破冰船奥登的探险来实现这一目标。这项工作涉及云形成气溶胶的观测和建模，旨在测试我们关于这些气溶胶来自何处以及它们如何帮助云形成的目标假设。具体而言，观测包括表征气溶胶物理、生物、化学和云形成特性的技术。这些测量将在破冰船上进行，直接在海冰上进行，并通过系留气球和直升机飞行的垂直剖面在低层大气中进行。与气团建模相结合，我们将使用这些观测结果来指导我们的合作者的云尺度建模模拟，该模拟将评估在不同的气团输送情景下由于气溶胶而导致的云特性变化。通过测试我们的假设，一个基本的表征和改进的了解气溶胶对北极云在春季海冰融化的影响。更广泛地说，该项目提供了一个独特的机会，以解决地球不断变化的大气对“新北极”海冰的影响，这一目标只能通过跨学科和国际合作才能成功实现。该项目团队包括4名女性和6名早期职业研究人员，并与两个非营利组织合作，通过现场虚拟活动和ARTofMELT探险博客与全球K-12教室交流学习目标，计划和成果。预计外展研讨会也将传达我们的研究结果，并更广泛地告知公众有关迅速变化的北极的各个方面。该奖项反映了NSF的法定使命，并被认为值得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来支持。

As the Arctic warms at least four times the global rate, features such as clouds impact the temperature at the surface. This is important because the Arctic is projected to become cloudier in the future, and temperature changes in the Arctic can influence global weather and climate. However, our understanding of Arctic clouds remains highly uncertain in part due to a poor understanding of airborne particles (called “aerosols”) that help them form, especially during the spring as the sea ice and snow start to melt. For this project, our goal is to improve our understanding of aerosols in the Arctic during the spring melt and how they impact clouds. We plan to accomplish this goal through international collaboration and participation in the Swedish-led ARTofMELT expedition in the Arctic Ocean during May–Jun 2023. This work involves both observations and modelling of cloud-forming aerosols designed to test our targeted hypotheses on where these aerosols come from and how they might help clouds form. By testing our hypotheses, an improved understanding of aerosol effects on Arctic clouds during the spring sea ice melt will be obtained. More broadly, the project provides a unique opportunity to address the impacts of the Earth’s changing atmosphere on sea ice in the “New Arctic,” a goal that can only be successfully accomplished through interdisciplinary and international collaboration. The project team includes 4 female and 6 early career researchers and involves engagement with two nonprofit organizations by communicating the study goals, plans, and outcomes through live virtual events and an ARTofMELT expedition blog with K-12 classrooms, globally. Outreach seminars are also anticipated to convey our findings, and more broadly, inform the public about aspects of the rapidly changing Arctic.As the Arctic warms at least four times the global rate, feedbacks from clouds will lead to compounding impacts on the surface energy budget that consequently affect regional and global weather and climate. However, our understanding of Arctic clouds remains highly uncertain in part due to a poor understanding of airborne particles (called “aerosols”) that help them form, especially during the spring as the sea ice and snow start to melt. For this project, our overarching goal is to improve our understanding of aerosol sources and cloud impacts in the Arctic during the spring melt. We plan to accomplish this goal through international collaboration and participation in the Swedish-led ARTofMELT expedition on the Icebreaker Oden in the Arctic Ocean during May–Jun 2023. This work involves both observations and modelling of cloud-forming aerosols designed to test our targeted hypotheses on where these aerosols come from and how they might help clouds form. Specifically, observations include techniques to characterize aerosol physical, biological, chemical, and cloud-forming properties. These measurements will be conducted on the icebreaker, directly on the sea ice, and in the lower atmosphere via vertical profiling on tethered balloon and helicopter flights. In tandem with airmass modelling, we will use these observations to guide our collaborator’s cloud-scale modelling simulations that will evaluate changes in cloud properties due to aerosols under different air mass transport scenarios. By testing our hypotheses, a fundamental characterization and improved understanding of aerosol effects on Arctic clouds during the spring sea ice melt will be obtained. More broadly, the project provides a unique opportunity to address the impacts of the Earth’s changing atmosphere on sea ice in the “New Arctic,” a goal that can only be successfully accomplished through interdisciplinary and international collaboration. The project team includes 4 female and 6 early career researchers and involves engagement with two nonprofit organizations by communicating the study goals, plans, and outcomes through live virtual events and an ARTofMELT expedition blog with K-12 classrooms, globally. Outreach seminars are also anticipated to convey our findings, and more broadly, inform the public about aspects of the rapidly changing Arctic.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.