Geological Surveys of Tonga
The violent eruption of the Hunga Tonga-Hunga Ha’apai volcano in Tonga injected an unprecedented amount of water directly into the stratosphere – and the steam will linger there for years, likely affecting Earth’s climate patterns, say scientists from The NASA.
The massive amount of water vapor is about 10% of the normal amount of vapor found in the stratosphere, which is equivalent to over 58,000 Olympic swimming pools.
“We’ve never seen anything like it,” said atmospheric scientist Luis Millán, who works at NASA. Jet Propulsion Laboratory. Millán conducted a study of the water that the volcano sent into the sky; the team’s research has been published in Geophysical Research Letters.
The volcano sent steam and gases to a record height
The January 15 eruption came from a volcano more than 20 km wide, with a caldera located about 500 feet below sea level. A day earlier, Tongan authorities reported the volcano was continuously erupting, sending a 3-mile-wide plume of steam and ash into the sky. Then the big explosion came, sending ash, gas and steam up to 35 miles – a record in the age of satellites – into the atmosphere.
Drones and other video from that day show the dramatic scale of the explosion, as the volcano launched an incredibly wide plume into the sky. The intense eruption sent a pressure wave around the Earth and caused a sonic boom heard as far away as Alaska.
The huge amount of water will likely increase temperatures
Previous large volcanic eruptions have affected the climate, but they generally cool temperatures as they send light-scattering aerosols into the stratosphere. These aerosols act like a kind of massive layer of sunscreen. But because water vapor traps heat, Tonga’s eruption could temporarily raise temperatures a bit, the researchers said.
It normally takes about 2-3 years for sulfate aerosols from volcanoes to fall from the stratosphere. But the water from the January 15 eruption could take 5-10 years to fully dissipate.
Given this time period and the extraordinary amount of water involved, Hunga Tonga-Hunga Ha’apai “may be the first observed volcanic eruption to impact climate not through surface cooling caused by aerosols. of volcanic sulfate, but rather by surface heating,” the researchers said in their paper.
NASA says the data for the study comes from the microwave limb sounder (MLS) on its Aura satellite, which measures water vapour, ozone, aerosols and gases in the Earth’s atmosphere.
The volcano interrupted the “heartbeat” of water in the stratosphere
The January 15 eruption severely disrupted annual hydrological patterns in the stratosphere (which also contains most of the atmosphere’s ozone).
The normal mechanism by which water rises in the stratosphere is so reliable that researchers call it a kind of tape recorder, marking annual temperature cycles through alternating bands of dry and moist air rising from the tropics.
January is normally the middle of the dry period in this seasonal cycle – but then the Tongan volcano erupted in the South Pacific Ocean, suddenly pumping a huge amount of water into the atmosphere.
“By short-circuiting the path passing through the cold spot, [Hunga Tonga-Hunga Ha’apai] disrupted this “heartbeat” signal” in the planet’s normal atmospheric water pattern, the researchers said.
They recommend monitoring the water from the volcanic eruption closely, both to predict its short-term impact and to better understand how future eruptions could affect the planet’s climate.