INPMOSAIC2

Arctic Ice Nucleation Sampling during MOSAiC

15 September 2019 - 31 October 2020

Lead Scientist: Jessie Creamean

Observatory: AMF

The accelerated rate of warming in the Arctic is of great concern due to potential impacts that include release of greenhouse gases from permafrost, melting glacial ice contributing to sea level rise, and declining sea ice cover exposing the darker ocean surface. These processes induce positive feedbacks and contribute to further warming that affects climate globally. Clouds play a crucial role in regulating the energy reaching the sea ice and snow surfaces, but the magnitude of their effects on surface temperature is not well constrained in the Arctic. Aerosols are also an important contributor by serving as seeds for cloud particle formation, but even less is known about their overall impact and origin. In particular, aerosols that serve as ice nucleating particles (INPs) are vastly understudied, especially above the central Arctic Ocean. However, INPs likely play a significant role in Arctic mixed-phase cloud (AMPC) microphysics and the resulting impacts of such clouds on the surface energy budget. To date, a full year’s worth of INP measurements have not been conducted anywhere in the Arctic and no INP data exist from the central Arctic in the winter or spring, creating a significant gap in understanding AMPC microphysical processes. The year-long transpolar drift experiment, Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC), will start in fall 2019 and provide the opportunity to execute these novel INP measurements. The overarching goal of this project is to achieve unprecedented characterization of INP abundance and sources (including biological) to evaluate their capacity to modulate cloud ice formation over the central Arctic. This project involves collection of total and size-resolved aerosol samples in the AMF2 on the German icebreaker Polarstern over an entire year to capture trends and variability spanning a full sea ice cycle. Additional resources will be obtained in the future to post-process samples for immersion mode INPs and DNA extraction and sequencing for microorganism characterization. Results from the future post-processing analyses will inform models of all scales through improvement of understanding Arctic aerosol-cloud interactions from detailed observations at the atmosphere-ocean-sea ice interface.