A discussion on the methods of extracting gravity wave perturbations from space‐based measurements

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The disparities in satellite‐based observations of global gravity wave activity are discussed in terms of methods used to extract the gravity wave perturbations from background and the sensitivity of the given satellite to the gravity wave spectrum. The temperature measurements from TIMED/SABER are used to obtain the global gravity wave maps in terms of their potential energies by employing two widely used methods to extract the gravity wave perturbations viz. (1) removal of 0–6 zonal wavenumber large‐scale waves and (2) high pass filter with cut‐off vertical wavelength at 10 km. The present study for the first time employed these two different methods on the same satellite observations to investigate the sensitivity of global gravity wave patterns and their magnitudes to the methods used to extract them. The results showed significant differences in the gravity wave potential energy magnitudes estimated by employing these two methods. Further, employing the first method on COSMIC‐measured temperature profiles, the global gravity wave pattern is estimated and the same is compared with that obtained using SABER observations. This comparison substantiated the assertion that using the same method to extract the gravity wave perturbations from different satellite observations yields the similar global gravity wave pattern. The present study thus provided very useful insights into the observed discrepancies among current global gravity wave patterns and it is envisaged that this is a step forward in unifying the existing methods to extract gravity wave parameters using space‐based observations.