AbstractThe results are given of the analysis of temperature and humidity fluctuations observed from an aircraft in 61 runs at heights of 30–550 m above the open sea in conditions of active convection in the south‐east Trades. The dimensionless temperature fluctuations varied with ( −z/L)−1/3for scale heights from about 0·2 to 2 but thereafter showed little change with height. The spectra obeyed the −5/3 power law for dimensionless frequencies in excess of about 0·3. The variance of virtual potential temperature showed a maximum at a lower dimensionless frequency than the variance of vertical air velocity observed during the same series of o