Regular trace gas and aerosol profile measurements in the Arctic troposphere: a key data gap in constraining Arctic processes and reducing model uncertainties

Although the Arctic is remote, it is far from pristine, with characteristic enhancements in air pollution thatcan affect climate, Arctic populations, and ecosystems. Long-range transport of pollution from lowerlatitudes and increases in local pollution sources contribute to enhancements in trace gas and aerosolconcentrations both at the surface and aloft throughout the Arctic troposphere. Moreover, changes in highlatitude fires, sea ice coverage, and the terrestrial environment are leading to changes in natural sourcesof trace gas and aerosol in the Arctic. Vertical enhancements of Arctic pollution are sensitive to differentsource locations, wet removal processes, and changes in large-scale transport patterns. Climate forcingdue to aerosol and trace gases is highly sensitive to their vertical distribution. However, there is virtually noregular sampling of Arctic trace constituent vertical profiles. This proposed activity is aimed at facilitatingArctic research community engagement in transforming our ability to monitor, understand, and predicttrace gas and aerosol abundances in the Arctic troposphere. A workshop will scope the potential for a newprogramme of regular trace gas and aerosol profile measurements from airborne platforms in the Arctic,and to discuss key research questions and model uncertainties that could be addressed with such aprogramme. The workshop will explore the potential for building capacity for such a regular measurementprogramme to be developed in time to be operational for the next International Polar Year (IPY) 2032-2033.