Atmospheric aerosol particles that can trigger ice formation in clouds are referred to as Ice Nucleating Particles (INP). The frequency and properties of clouds in the Arctic are especially sensitive to concentrations of INPs, yet the main sources and concentrations of INPs in this region remain uncertain. Over the past 30 years, warming in the Arctic has decreased sea ice and land snow by 20% and 13%, respectively. When glaciers and permafrost in the Arctic melt, erodible soil is exposed, and this soil can be a potential source of mineral dust in the Arctic. Similarly, as sea ice cover in the Arctic diminishes and sea surface temperatures increase, the production of sea salt spray will increase. Both mineral dust and sea salt spray can act as INPs. An international study led by Canadian, French and U.S. researchers (Professor Alexander Laskin, Chemistry), set out to measure the concentrations of INPs in the Canadian Arctic and provide insights into the source of these particles in the region. The researchers found that mineral dust, sourced from the region, is a more important contributor to the INP population than sea spray aerosols. Warming in the Arctic will likely increase concentrations of INPs from mineral dust in the region, with important implications to climate in the region.
Irish, V.E., S. J. Hanna, M. D. Willis, S. China, J. L. Thomas, J. J. B. Wentzell, A. Cirisan, M. Si, W. R. Leaitch, J. G. Murphy, J. P. D. Abbatt, A. Laskin, E. Girard, A. K. Bertram (2019). Ice nucleating particles in the marine boundary layer in the Canadian Arctic during summer 2014. Atmos. Chem. Phys., 19, 1027–1039.