ESA Water Vapour Climate Change Initiative - 2nd User workshop

Long-term response in stratospheric water vapour and radiative forcing from the Hunga Tonga-Hunga Ha’apai eruption

16 Oct 2024, 09:45

15m

Room 4001b (FZ Jülich; Building 15.9 (INM))

oral Stratospheric Water Vapour

Speaker

Hao Ye (University of Reading)

Description

The climactic Hunga Tonga-Hunga Ha’apai (HT-HH) eruption injected an unprecedented amount of water vapour into the stratosphere. As part of the ESA Water Vapour Climate Change Initiative (WV_cci), new vertically resolved climate data records (CDRs) of water vapour in the stratosphere and upper troposphere are used to study the evolution of water vapour injected into the stratosphere. The local stratospheric water vapour increased dramatically after the eruption, and the moist signal was transported upwards and then horizontally to high latitudes in the stratosphere by the Brewer-Dobson Circulation (BDC). The stratospheric water vapour increases by 1.1 ppmv globally between 100 — 0.1 hPa in December 2023, a signal from the eruption still seen after nearly two years. At the same time, this increase in stratospheric water vapour has an impact on the local dynamic circulation, including a slowdown in the BDC. Using an off-line radiative transfer model, we estimate the radiative forcings from the injected water vapour in the upper troposphere and stratosphere.