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

Colorado State University, Fort Collins CO

Investigators

Abstract

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.