Comparisons of mean ambient temperature, specific humidity, static pressure, and horizontal wind from the five Tropical Ocean-Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) boundary layer aircraft were obtained from 38 two- and three-aircraft, close-formation, level runs. These, together with consideration of surface measurements from buoys and ships, led to proposed empirical corrections for the aircrafts temperature, humidity, and pressure measurements, minimizing the systematic errors between the aircraft data sets. The aircraft-measured winds were also compared. The TOGA COARE bulk flux algorithm was used to extrapolate the low-level aircraft data to the individual ship and buoy sensor heights for 267 overflight comparisons. In addition, all low-level aircraft data and corresponding ship and buoy data from boundary layer missions were extracted and adjusted to a 10-m reference height. The recommended aircraft corrections bring the aircraft-ship-buoy data sets into better agreement, resulting in a consistent data set for air-sea interaction analyses. Frequency distributions of the 10-m aircraft, ship, and buoy data from the boundary layer missions also agree. ¿ 1999 American Geophysical Union