Aircraft measurements of gravity waves in the upper troposphere and lower stratosphere during the START08 field experiment

The power spectra of the horizontal velocity components and potential temperature for the scale approximately between ~8 and ~256km display an approximate -5/3 power law in agreement with past studies on aircraft measurements, while the fluctuations roll over to a -3 power law for the scale approximately between ~0.5 and ~8km (except when this part of the spectrum is activated, as recorded clearly by one of the flight segments).

However, at least part of the high-frequency signals with sampled periods of ~20 - ~60s and wavelengths of ~5 - ~15km might be due to intrinsic observational errors in the aircraft measurements, even though the possibilities that these fluctuations may be due to other physical phenomena (e.g., nonlinear dynamics, shear instability and/or turbulence) cannot be completely ruled out.