Ice Nucleation from Ship Emissions

Abstract:

Atmospheric ice particles play a significant role in many atmospheric processes and are central to the role of clouds in determining the global radiative balance. Atmospheric ice originates when Ice Nucleating Particles (INP) lower the free energy barrier to phase transformation. The Earth's polar regions are well isolated from the middle and lower latitudes and thus have limited access to INP, and therefore small changes in terms of regional sources or large scale transport of particulate may have significant impacts on polar ice cloud formation. Here we describe field measurements of INP collected in the Port of Gothenburg, Gothenburg, Sweden. The port is the largest Scandinavian seaport and thus has heavy and diverse ocean vessel traffic. Unique to this study was the ability to isolate the INP contribution directly from the ship traffic by utilizing a sampling method that nearly simultaneously captured transiting ship plumes and the background aerosol. A small but potentially significant increase in IN from marine vessels was observed over two consecutive years. The results have implications for Arctic and global climate in the context of growing global commerce and trans-polar transport.