The 5th biennial AOS will be held in 2020 in Akureyri, Iceland (March 31- April 2) as part of ASSW 2020 (27 March – 2 April). The theme of AOS 2020 is "Observing for Action". Additional details can be found here. The AOS fosters communication and international collaboration and coordination of long-term observations aimed at improving understanding of and response to system-scale Arctic change. The AOS is an international forum for optimizing resource allocation, and minimizing gaps and duplication, through coordination of and exchange among researchers, agencies, Indigenous Peoples, non-governmental organizations, the private sector and others involved or interested in long-term observing activities. The AOS serves as a platform to identify and address societal and scientific needs and priorities, minimize gaps in data and information, reduce duplication, improve coverage and breadth, and contribute to solution-based applications and knowledge sharing.