In total five low-level flights were flown, measuring turbulent wind, temperature and humidity. The air-sea fluxes were estimated using the eddy covariance method for flux runs of 2 minutes (approximately 12 km) at typical altitudes of 30-40 m above the sea surface. In total there were 131 flux runs, 121 over open water, the remainder over sea ice or the marginal ice zone. Strict quality control procedures have been applied, resulting in a total of 112 runs over open water for wind stress and sensible heat fluxes and 106 for latent heat fluxes.
The mean 10-m neutral wind speed of the flux runs varies from 5 to 25 m -1 with 80% of the runs in the range 14-19 m s-1. The measured wind stress over open water has a range of 0.1-1.6 N m-2. The sensible and latent heat fluxes over open water vary between 50 and 300 W m-2. The mean exchange coefficients for the interval 15-18 m s-1 are CDN = 2.1 x 10-3, CHN = 1.7 x 10-3 and CEN = 1.6 x 10-3. These coefficients are somewhat higher than most previous studies have suggested, although they are within the range presented for the few high wind speed data sets that are available.