The air Pollution in the Arctic: Climate, Environment and Societies (PACES) initiative is bottom-up community activity aiming to address deficiencies in our understanding of sources, processing and fate of Arctic air pollution.

PACES is an IGAC-sponsored initiative, which aims to review existing knowledge and foster new research on the sources and fate of Arctic air pollution, its impacts on climate, health, and ecosystems, on the feedbacks between pollution and natural sources, on climate responses, and on societal perspectives, including sustainability, adaptation and economic feedbacks. PACES coordinates international research efforts on these topcs in collaboration with existing and planned initiatives such as HTAP, AMAP, PEEX, YOPP, IASOA, MOSAiC and ArcticStar and motivates trans-disciplinary research related to Arctic air quality.Specifically, PACES Working Group 1 (WG1) is focused on improving predictive capability around transport of lower latitude pollution to the Arctic and its impacts on climate.

In September 2018, around 20 participants from Europe, North America and Asia met in Takamatsu, Japan to explore plans for new field and modeling initiatives aimed at addressing key uncertainties in these processes.
A major focus of the workshop discussion was the proposed “Investigation of Multiscale Processes Affecting Atmospheric Chemical Transport” (IMPAACT) experiment, which aims to use aircraft to track polluted air masses exported from China out over the Pacific and polewards towards the Arctic. Key uncertainties to be addressed include pollutant transformation and washout during frontal export, and chemical and physical pollutant transformation following continental export and en route to the Arctic. While funding for a central IMPAACT activity is yet to be obtained, several other international aircraft groups described plans that would align well to the IMPAACT goals. Groups from Asian countries, including Japan, expressed interest in conducting linked ship and ground-based activities. PACES WG1 modelling activities were presented, which include using novel perturbed parameter ensemble approaches to robustly identify key processes leading to model uncertainty in Arctic pollutant burdens and distributions. Outcomes from the workshop include the establishment of a PACES WG1 steering group, aimed at coordination of separate aircraft and other field efforts to address the PACES WG1 and IMPAACT goals, as well as plans for modeling work aimed at identifying target processes and species for new aircraft measurements to be made during IMPAACT type experiments.

More information at PACES website