Abstract/Summary

The violent eruption of the Hunga Tonga-Hunga Ha’apai volcano in January 2022 produced an outward spreading pressure wave travelling around the globe many times, reminiscent of similar effects from the 1883 Krakatoa eruption. The Tonga pressure wave caused transient changes in UK atmospheric pressure on 15th January about 15 hours after the eruption, initially passing southwards, followed by further changes travelling northwards about 6 hours later. Subsequent pulses from further circumnavigations were detected for several days. Features of the initial pressure wave in the UK and later pulses in surface pressure data at Reading are described here, together with evidence for a local disturbance in low cloud from the first pressure pulse.