During the second Chinese National Arctic Research Expedition (CHINARE 2003), four Argos buoy were deployed in the western Arctic marginal ice zone (MIZ). Two buoys made in China by the National Technical Institute of Oceanography were equipped with a small weather mast measuring the wind components, temperature and air pressure. In addition, the ocean temperature and salinity were measured at several levels close to the ice bottom. Another two buoys were mounted with sensors to measure air temperature and pressure, and the ice/snow temperature at ten levels. The buoys yielded data from 3 to 9 months. The mean ice drift was westwards, related to the large-scale atmospheric pressure patterns but also affected by the internal resistance of the icefield. The snow and ice mass balance were estimated on the basis of heat budget calculations at the air–snow and ice–water interfaces, utilizing measurements of the temperature profile in the ocean, ice and snow, as well as the air temperature and wind speed. For thick ice, a melting period probably occurred during the cold season. The oceanic heat flux was a key constituent of the energy and mass balance at the sea-ice bottom. A numerical model (HIGHTSI), forced by the ERA-Interim reanalysis data, was applied to calculate the snow and ice mass balance, and the results were compared with buoy measurements.