Tag Archives: Explosion

Tonga explosion’s weather effects probably small

From Net Zero Watch

The weather in many regions of the world has been particularly noteworthy recently. But what’s behind it?

Dr David Whitehouse, Science editor

Some have pointed to the violent Hunga Tonga-Hunga Ha’apai (HTHH) eruption on 15th January this year which was the largest explosion ever recorded by modern instruments – far larger than any nuclear test. It was the most powerful explosion since the 1883 Krakatoa event.

Producing the highest known eruption column in history, its effects reached the mesosphere. Because the volcano was 150 metres below sea level the explosion injected water vapour as high as 53 km. Large amounts of water ended up in the stratosphere, surpassing anything we have seen since satellite observation of such events commenced in the 1970s.

Image: NOAA

According to an assessment of the event researchers said it, “ranks it among the most remarkable climatic events in the modern observation era, with a range of potential long-lasting repercussions for stratospheric composition and climate”. 

Observations from NASA’s Aura satellite estimates that the explosion may have added 10% of the typical amount of water vapour into the stratosphere. Water vapour is a powerful greenhouse gas because it traps heat over a wider range of the infra-red spectrum than carbon dioxide. This effect is short-lived though as it soon enters the natural water cycle.

However unlike previous eruptions it may not cool the surface but warm it. This is because it released little in the way of sunlight-reflecting aerosols. The effect could be quite small, or it might not. One estimate suggests 0.035°C over the next 5 years which is within the “noise” of variability. So HTHH is likely to have only a small effect — as far as we know at present. Jucker at alon the other hand suggest the effect could be long-term winter warming in the northern hemisphere and cooling over Australia in winter.

The recent warmth has also been attributed to El Nino; but it is currently still rather weak, although strengthening.

Thus is seems unlikely that these events have significantly affected recent weather, though we should heed the words of Agatha Christie who once wrote: “Any coincidence is worth noticing. You can throw it away later if it is only a coincidence.”

Feedback: david.whitehouse@netzerowatch.com

An Earth-Directed Explosion on the Sun

From Spaceweather.com


April 21, 2023: Earth is in the strike zone. On April 21st, a large magnetic filament snaking across the sun’s southern hemisphere exploded, hurling a cloud of debris in our direction. This movie from NASA’s Solar Dynamics Observatory shows what happened:

Soon after the eruption, the US Air Force reported strong Type II and Type IV solar radio bursts. These are natural shortwave emissions produced by shock waves preceding the CME as it passes through the sun’s atmosphere. Drift rates in the Type II burst suggested a CME velocity of about 580 km/s (1.3 million mph).

Images from SOHO coronagraphs have since confirmed the CME. It is a “halo CME” heading straight for Earth:

Models from NASA and from NOAA agree: the CME should reach Earth during the early hours of April 24th between the hours of 00:00 and 12:00 UT. The impact could spark G1- (Minor) to G2-class (Moderate) geomagnetic storms, with a slight chance of G3 (Strong). Aurora alerts: SMS Text.

A BURST OF STATIC FROM THE SUN: The explosion that hurled a CME toward Earth on April 21st also illuminated our planet with an intense burst of shortwave radio static. Amateur astronomer Thomas Ashcraft of New Mexico recorded the outburst:

“Few solar radio bursts show as hot purple on my spectrograph, but this one ‘rang the bell’,” he says. “Here is an audio recording in stereo with 22 MHz in one channel and 19 MHz in the other.”

The static in Ashcraft’s recording, which washes over the listener like a slow ocean wave, is naturally produced. Astronomers classify it as a Type V solar radio burst caused by energetic beams of electrons ray-gunning through the sun’s atmosphere. The electrons were accelerated by the same underlying explosion that hurled a CME toward Earth.

Solar radio bursts are an underappreciated form of space weather. We often talk about radio blackouts, which happen when solar flares ionize the top of Earth’s atmosphere. A radio blackout suppresses the normal propagation of terrestrial radio signals. Solar radio bursts, on the other hand, produce a radio drownout. Intense static from the sun overwhelms normal transmissions, drowning out the voices radio operators are trying to hear.

Solar radio bursts will happen more and more often as Solar Cycle 25 intensifies. You can hear them youself using a RadioJOVE radio telescope kit from NASA.