A new international study will examine whether the eruption of a Tongan volcano last year can be linked to extreme weather events experienced in New Zealand, including Cyclone Gabrielle.

NIWA principal atmosphere and climate scientist Olaf Morgenstern says there is no established link between the events, but it's believed the eruption increased the earth's temperature.

The underwater Hunga Tonga-Hunga Ha'apai volcano sent about 58,000 Olympic-sized swimming pools of seawater into the earth's stratosphere when it erupted in January 2022.

'That water acts like a shield and enhances the green house emissions and enhances the warming,” says Morgenstern.

One year later, a preliminary calculation has been done that suggests the eruption increased the earth's surface by 0.1C.

That's a very small amount in terms of the overall global warming behind the increase in extreme weather events being experienced in the North Island, he says.

'The idea that New Zealand has been hit this summer by a deluge of rain is entirely consistent with what we expect based on global warming.”

An international modelling exercise has been initiated to look at the climactic effects of the Tongan volcano eruption.

It would be at least two years before there were any confirmed conclusions from the research, he said.

Last year, Stuff reported that powerful volcanic eruptions like Pinatubo or Krakatoa actually cooled the Earth's surface temperature because the gas, dust and ash they spew reflects sunlight into space.

But water vapour sent into the atmosphere can trap heat, and the excess amount from the Tonga volcano could stay in the stratosphere for up to 10 years before it fully dissipated.

The warming effect of the water vapour was expected to be small and researchers did not believe it would be enough to exacerbate the climate crisis.

Scientists recorded the highest ash plume ever measured after the Tongan eruption and a 58 kilometre aerosol cloud 'overshoot” that touched space beyond the mesosphere.

It also triggered the largest number of lightning bolts recorded for any type of natural event and created 'sonic booms” (atmospheric pressure waves) and tsunami that travelled the entire world.

-Debbie Jamieson/Stuff.