POLARCAT will bring together intensive aircraft experiments, research ship cruises, monitoring activities at surface stations, ground-based remote sensing, balloon releases, satellite measurements, and a range of different models. In order to achieve its overall goals, POLARCAT will closely co-ordinate these different activities. For instance, the aircraft and shipboard experiments will be supported by forecasts from meteorological and chemical models, satellite observations, surface networks and enhanced ozone sonde releases. In some cases, pathfinder aircraft carrying remote sensing instrumentation will be used to guide other aircraft carrying in-situ instrumentation into pollution layers.

Aircraft measurements will also be closely co-ordinated with each other and with the releases of Lagrangian balloons, in order to sample the same polluted air masses repeatedly. Such a Lagrangian approach will allow constraining the overall chemical budget in an air parcel between individual observations.

The airborne measurements will be coordinated with satellite overpasses, especially of Aura, Aqua, Terra, Envisat, and Calipso. Validation of the satellite observations of tropospheric composition and aerosol parameters will receive a high priority. Vertical aircraft profiling will also be done above surface stations and the ship, in order to characterize the vertical (and horizontal) extent of phenomena observed at the stations. POLARCAT will also work together closely with other IPY core activities. For instance, it is planned that aircraft perform overflights over the icebreakers used in other programs and field sites participating in Arctic wide studies (e.g. IASOA).

POLARCAT is a bottom-up project that will remain open for others to join. Therefore, the following description of activities reflects the current stage of planning. Additional activities can be suggested by others and added at any time.