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的四倍，云层等特征会影响地表的温度。这一点很重要，因为北极预计未来会变得更加多云，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非常不确定，部分原因是对帮助它们形成的空气中的颗粒(称为“气溶胶”)缺乏了解，特别是在春季海冰和雪开始融化的时候。对于这个项目，我们的目标是提高我们对北极春季融化期间的气溶胶及其如何影响云层的理解。我们计划通过国际合作和参与瑞典领导的2023年5月至6月在北冰洋的ARTofMELT探险队来实现这一目标。这项工作包括对形成云的气溶胶的观测和建模，旨在测试我们关于这些气溶胶来自哪里以及它们可能如何帮助云形成的目标假设。通过检验我们的假设，我们将更好地理解春季海冰融化期间气溶胶对北极云的影响。更广泛地说，该项目提供了一个独特的机会来解决地球大气变化对“新北极”海冰的影响，这一目标只有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，通过在全球范围内通过现场虚拟活动和带有K-12教室的ARTofMELT探险博客交流研究目标、计划和结果，与两个非营利性组织接触。预计外展研讨会还将传达我们的发现，更广泛地向公众介绍快速变化的北极的各个方面。由于北极变暖的速度至少是全球速度的四倍，来自云的反馈将导致对地表能源收支的复杂影响，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非常不确定，部分原因是对帮助它们形成的空气中的颗粒(称为“气溶胶”)缺乏了解，特别是在春季海冰和雪开始融化的时候。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。我们计划通过国际合作和参与瑞典领导的2023年5月至6月在北冰洋奥登破冰船上的ARTofMELT探险队来实现这一目标。这项工作包括对形成云的气溶胶的观测和建模，旨在测试我们关于这些气溶胶来自哪里以及它们可能如何帮助云形成的目标假设。具体地说，观测包括表征气溶胶的物理、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较低的大气中进行。在气团模拟的同时，我们将使用这些观测来指导我们的合作者的云尺度模拟，该模拟将评估不同气团输送情景下气溶胶引起的云属性变化。通过检验我们的假设，我们将获得关于春季海冰融化期间气溶胶对北极云影响的基本特征和更好的理解。更广泛地说，该项目提供了一个独特的机会来解决地球大气变化对“新北极”海冰的影响，这一目标只有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，通过在全球范围内通过现场虚拟活动和带有K-12教室的ARTofMELT探险博客交流研究目标、计划和结果，与两个非营利性组织接触。外展研讨会也有望传达我们的发现，更广泛地，让公众了解快速变化的北极的方方面面。这一奖项反映了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。

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.