Tonga Volcano - Will It Mean an "Ash Winter" ?

[Unknown]

Large volcanic eruptions have caused global-scale
cooling before - sometimes even "years without a
summer" and serious crop failures.

The Tonga volcano was a BIG boom. The view from
weather sats and the ISS were extremely impressive,
or scary if you prefer. A VAST ash-cloud blasted
high and wide. Within a month the ash will have
spread worldwide, though the worst effects may
be in the southern hemisphere.

In short, even for the north, this winter may
be prolonged and the summer short and cool.
One proposed fix for GW is to seed the upper
atmosphere with micron-sized particles which
would remain afloat for a year or two. Well,
this volcano may have done just that - and
not in a controllable fashion.

On top of Covid expenses, how much more
economic damage is tolerable ? Bad crop
yeilds would normally be survivable, but
right NOW ....

[N_Cook]

My halfpennyworth
Looks like NASA assessed the Tonga eruption at 10 megatons of TNT,
compared to Pinatubo and Krakatoa of 200 megatons , so I doubt its
after-efects will be observable in the global geodata beyond 1 year
timescale, if at all .
Or 1/10 of the effect of 1991 Mt Pinatubo, that took about 10 years to
drop out of its effect on global geodata and return to the new normal.
Or 1/10 of the immediate global aftermath to the Pinatubo eruption, ie
negligible globally.


--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>

[1.AAC0832]

Not as much energy as Krakatoa ... however that's not
the only parameter. The quantity/quality of the ash
plays a big role. The Tonga blast was almost like a
shotgun fired straight up. In any case, we will just
have to wait and see. I've seen no solid figures yet
profiling the likely climatic impact. Might be too
soon.

[N_Cook]

I see in the news today, that from satellite imagery its been determined
tha the highest ash reached 35 miles altitude, which does seem to be
problematicly high, implying extra fineness.

[1.AAC0832]

35 miles is not to be laughed about - halfway to
de-facto space, way into the stratosphere. The
particles will hang up there for quite awhile.

https://www.livescience.com/tonga-volcano-ash-record-altitude

Tonga apparently has the (known) record.

A key issue is how much sulfate particulates result. That
seems to be primary to effects on solar IR. Coming out of
the ocean bottom, millions of years worth of dead critters,
the sulfates could be quite high. I don't *think* Tonga
is at a subduction zone - where all those organics get
pulled under and pressure-cooked. So, it could have
been worse.

But, data IS incomplete as of yet. We'll have to wait
and see. But if April seems more like February this year,
well, we'll know why.

We also don't know if the thing will explode AGAIN.
The caldera collapsed ... but in doing so would have
trapped a lot of seawater down there. Bubble bubble .

It seems that there's more seismic/volcanic activity
in the Ring Of Fire lately. Old magmatic reserves
blasted out in the 17/1800s might now have been
replenished. IF there's a new cycle of big blasts
coming, well, we'll all HOPE for some global warming.
A 0.5/1.0C drop in global temperatures will have a
large effect on agricultural output because it will
mean a considerable drop in insolation.