Figure 2

Left panels: high-pass filtered (cut-off period of 2 h) atmospheric pressure time series (in hPa) spanning the period from 0400 UTC 15th January 2022 to 1600 UTC 19 January 2022 (red lines). The location of the series is shown in Fig. 1, and the distance to Tonga is indicated in each plot. The simulated atmospheric pressure anomaly obtained by Ref.¹³ is also included (black lines) shifted 2 hPa for clarity. Central panels: wavelet power spectrum (in log₁₀ (hPa²)) of the non-filtered atmospheric pressure series at the same locations. The arrows indicate the arrival time of the different wave passages. Right panels: ratio between the energy spectrum computed for each passage (1st in solid blue; 2nd in dashed red; 3rd in solid green; 4th in dashed purple) and the background red-noise spectrum. The energy spectra have been estimated by averaging the WPS over a 1 h period centered at each passage time. The solid black line indicates the 95% significance level estimated as described in Ref.²³.