Data and code from: Long-term climate impacts of large stratospheric water vapor perturbations

The amount of water vapor injected into the stratosphere after the
eruption of Hunga Tonga-Hunga Ha’apai (HTHH) was unprecedented, and it is
therefore unclear what it might mean for surface climate. We use chemistry
climate model simulations to assess the long-term surface impacts of
stratospheric water vapor (SWV) anomalies similar to those caused by HTHH,
but neglect the relatively minor aerosol loading from the eruption. The
simulations show that the SWV anomalies lead to strong and persistent
warming of Northern Hemisphere landmasses in boreal winter, and austral
winter cooling over Australia, years after eruption, demonstrating that
large SWV forcing can have surface impacts on a decadal timescale. We also
emphasize that the surface response to SWV anomalies is more complex than
simple warming due to greenhouse forcing and is influenced by factors such
as regional circulation patterns and cloud feedbacks. Further research is
needed to fully understand the multi-year effects of SWV anomalies and
their relationship with climate phenomena like El Nino Southern
Oscillation.