Responses to reviewer comments

The reviewer makes an important point regarding our interpretation of Fig. 1. Since it is derived from global reanalysis – our 5 proxy for observations – it is important to acknowledge that the signature seen in the figure is not guaranteed to be a pure AEW packet that is evolving independently of external influences. Indeed, as the reviewer points out, the modulation of AEWs by the Madden-Julian Oscillation, convectively coupled Kelvin waves, and breaking extratropical waves can give the appearance of a dispersing wavepacket if there is a preferential amplification of one part of the packet compared to the other. As recommended, we have now added a paragraph that explicitly states the caveat in our interpretation in section 2.1. 10