The main mission of the International Arctic Systems for Observing the Atmosphere (IASOA) is coordination of atmospheric data collection at existing and newly established intensive Arctic atmospheric observatories. Data of interest to the IASOA consortium include measurements of standard meteorology, greenhouse gases, atmospheric radiation, clouds, pollutants, chemistry, aerosols, and surface energy balances. These measurements support studies of Arctic climate change attribution (why things are changing), not just trends (how things are changing). IASOA is responsive to growing evidence that the earth system may be approaching environmentally critical thresholds within decadal time scales. The information from IASOA will not only enhance scientific understanding but will also support decisions by the global community regarding climate change mitigation and adaptation strategies. Main gaps: Not all observatories are members of established global networks such as GAW and BSRN. It is recommended that IASOA observatories that are not members of these global networks be evaluated for potential membership and that roadblocks to membership be investigated. Other types of measurement gaps include, but are not limited to: (1) Radar-lidar pairs at each observatory to assess cloud properties; (2) Flux towers at each observatory for methane and CO2 fluxes; (3) Aerosol measurements at each observatory; and (4) Surface and upper air ozone measurements at each observatory. Network type: Predominantly atmospheric measurements.