Chile's volcano not likely to affect the climate
It's been a busy month for natural disasters, and I haven't found time to talk about Chile's Chaiten volcano, 760 miles (1,220 km) south of the capital Santiago. The volcano started erupting on May 2 for the first time in thousands of years, spewing ash, gas and molten rock into the air, forcing the evacuation of thousands of people. Did this mighty eruption have a cooling effect on the climate?
Figure 1. This May 5, 2008 image from NASA's Terra satellite caught Chaiten erupting. Image credit: NASA.
Many historic volcanic eruptions have had a major cooling impact on Earth's climate. However, Chaiten is very unlikely to be one of them. To see why this is, let's examine recent volcanic eruptions that have had a significant cooling effect on the climate. In the past 200 years, Mt. Pinatubo in the Phillipines (June 1991), El Chichon (Mexico, 1982), Mt. Agung (Indonesia, 1963), Santa Maria (Guatemala, 1902) Krakatoa (Indonesia, 1883), and Tambora (1815) all created noticeable cooling. As one can see from a plot of the solar radiation reaching Mauna Loa in Hawaii (Figure 2), the Mt. Pinatubo and El Chichon eruptions caused a greater than 10% drop in sunlight reaching the surface. The eruption of Tambora in 1815 had an even greater impact, triggering the famed Year Without a Summer in 1816. Killing frosts and snowstorms in May and June 1816 in Eastern Canada and New England caused widespread crop failures, and lake and river ice were observed as far south as Pennsylvania in July and August. Volcanic eruptions cause this kind of climate cooling by throwing large amounts of sulfur dioxide gas into the stratosphere. This gas reacts with water to form sulphuric acid droplets (aerosol particles), which are highly reflective, and reduce the amount of incoming sunlight.
You'll notice from the list of eruptions above that all of these climate-cooling events were from volcanoes in the tropics. Above the tropics, the stratosphere's circulation features rising air, which pulls the sulfur-containing volcanic aerosols high into the stratosphere, where the upper-level winds circulate them all around the globe. These aerosol particles take a year or two to settle back down to earth, since there is no rain in the stratosphere to help remove them. However, if a major volcanic eruption occurs in the mid-latitudes or polar regions, the circulation of the stratosphere in those regions generally features downward subsiding air, and the volcanic aerosol particles are not able to penetrate high in the stratosphere and get carried all around the globe. Chaiten is located near 40° south latitude, far from the tropics, and thus is unlikely to be able to inject significant amounts of sulfur aerosols into the stratosphere. Furthermore, the character of Chaiten's eruptions so far has been to eject a lot of silica and not much sulfur into the air. The total amount of sulfur ejected has been only about 1/10000 of what Mt. Pinatubo put into the air, according to NASA.
Figure 2. Reduced solar radiation due to volcanic aerosols as measured at Mauna Loa Observatory, Hawaii. Image credit: NOAA/ESRL.
Realclimate.org has a nice article that goes into the volcano-climate connection in greater detail. One interesting quote from the article: There can be some exceptions to the tropics-only rule, and at least one high latitude volcano appears to have had significant climate effects; Laki (Iceland, 1783-1784). The crucial factor was that the eruption was almost continuous for over 8 months which lead to significantly elevated sulphate concentrations for that whole time over much of the Atlantic and European regions, even though stratospheric concentrations were likely not particularly exceptional.
My next blog will talk about new research regarding the hurricanes/global warming connection.
Jeff Masters
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Looks as if my low pre-season March predictions for this season may actually come true!
Hopefully we'll have a season like 1977, 1992 or 1997...where everything remains quiet and out to sea in the atlantic. That's the way it looks like it will be this season. Tranquil Tropics
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Wow, Dont hype a decrease in SOI values to this extent. The season still in my opinion looks to be very active with the high setting up to place a huge threat to the U.S., If your familar with SOI values then you would know this happens quite often, Although this is a huge change, IT can climb back up just as fast.
June1 456 but we are almost 3 months form the meat of the season.
true...and i dont look forward to it....I havnt been directly affected by a hurricane in 10 years some say 9 and I dont plan on breaking it. A hurricane and a little island is like a sand castle meets the ocean wave.
1360. hurricane23 6:22 PM AST on May 20, 2008
June1 456 but we are almost 3 months form the meat of the season.
true...and i dont look forward to it....I havnt been directly affected by a hurricane in 10 years some say 9 and I dont plan on breaking it. A hurricane and a little island is like a sand castle meets the ocean wave.
Maybe you should invest in a boat lol...
From those models Drak, I'd think that next year has a far greater potential of being under El Nino conditions than this year...
The SOI doesn't have to decrease at a constant rate...in fact, it may jump right back up again. While a large negative "skip" may have occured, we're still in a La Nina, and the SOI does not necessarily have to decrease at a constant or larger rate every time.
I am not convinced that we will have an El Nino for this season; even in the unlikely event that we do have an El Nino this year, it will be a very weak warm anomaly and thus will not "destroy" hurricane activity as some have been saying it will.
Looks as if my low pre-season March predictions for this season may actually come true!
Hopefully we'll have a season like 1977, 1992 or 1997...where everything remains quiet and out to sea in the atlantic. That's the way it looks like it will be this season. Tranquil Tropics
It wasnt that tranquil, 1977 Hurricane Anita hit Mexico as a Cat.5, 1992 Hurricane Andrew hit Florida as a Cat.5 then Louisiana as a Cat.3, 1997 Hurricane Danny hit Louisiana and then Alabama.
ENSO model forecast:
From those models Drak, I'd think that next year has a far greater potential of being under El Nino conditions than this year...
The SOI doesn't have to decrease at a constant rate...in fact, it may jump right back up again. While a large negative "skip" may have occured, we're still in a La Nina, and the SOI does not necessarily have to decrease at a constant or larger rate every time.
I am not convinced that we will have an El Nino for this season; even in the unlikely event that we do have an El Nino this year, it will be a very weak warm anomaly and thus will not "destroy" hurricane activity as some have been saying it will.
2004 had a mild El Nino and look what happened lol!
We may have 90L vary soon
lol. Are you copying Taz?
Yep; 2004 being a perfect example of an active, destructive El Nino year.
1365 comments, in a day and a half ?
WOW guys, is it even going to be possible, to simply read all the entries, when a storm blows up ??
How about, you cannot post, unless you are within say, 500 miles of it when it happens
LOL
Hi.
1365 comments, in a day and a half ?
WOW guys, is it even going to be possible, to simply read all the entries, when a storm blows up ??
How about, you cannot post, unless you are within say, 500 miles of it when it happens
LOL
LOL the season is drawing near and the GFS is keeping people's interest for the most part.
lol
And a good friend too.
If you look back at Last year and 06,,..he was right more than not.
1378. pottery 10:33 PM GMT on May 20, 2008
Hi.
1365 comments, in a day and a half ?
WOW guys, is it even going to be possible, to simply read all the entries, when a storm blows up ??
trust me..... half the post were unrelated to weather. Maybe when the season comes around....we would have alot of comments still but of weather discussions.
Im betting Taz Knows when 90L will form,where and If it will be a Threat.
If you look back at Last year and 06,,..he was right more than not.
Taz should be added to the model suites.
If that disturbance in the SW Caribbean was to move northward and get a decent distance away from land, It could easily become a tropical depression, However that is not the situation so it won't happen.
If a frog had wings it wouldn't bump it's a$$ every time it hopped. LOL
Still at it...
Hi.
1365 comments, in a day and a half ?
WOW guys, is it even going to be possible, to simply read all the entries, when a storm blows up ??
Set your comments filter to Med-High and..
"Set it,and Forget it"
Anybody watching the new GFS?
Still at it...
I have been refreshing the page while blogging lol. The GFS is still penchant on development and closing in on the time frame.
1314. CaneAddict 5:09 PM EDT on May 20, 2008
If that disturbance in the SW Caribbean was to move northward and get a decent distance away from land, It could easily become a tropical depression, However that is not the situation so it won't happen.
If a frog had wings it wouldn't bump it's a$$ every time it hopped. LOL
ROFL!
Had some rough weather roll through here. Looks like some headed your way press.
Also noticed that the GFS has now lost the Carib disturbance for several runs in a row. What it is still hinting at, and has been to some extent for a week or so, is development from the front that will stall off the E coast in a few days. May at least be something interesting to watch.
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