[d.patterson]

Just thought id drop this topic in and see what others views are on this.

In the 1300's a series of large volcanic eruptions caused a cooling effect on the planet. as per the below attached article

http://www.bbc.co.uk...onment-16797075

I wonder if the recent large volcanic eruptions i.e from the Icelandic and Chilean volcano's have caused a cooling effect for us at present?

See what the next cycle bring us????

[Andy Mayhew]

Recent volcanic activity hasn't been anywhere near enough to affect climate - and eruptions also need to be near the equator to have any global effect. The last such was Pinatubo. But an interest bit of research there, thanks for flagging it up. See also:

http://www.scienceda...20130131509.htm

No mention though of which volcanoes. I'm guessing therefore that at this stage it's pure speculation, until we find the smoking caldera ....

[PK2]

Andy Mayhew, on 31 January 2012 - 10:18, said:

No mention though of which volcanoes. I'm guessing therefore that at this stage it's pure speculation, until we find the smoking caldera ....

I'm sure I saw an article about this naming at least some of the volcanoes. Can't find it now though
EDIT: think it might be my memory playing up the BBC article mentions one (Kuwae) but that's "later" rather than the initial four .

This post has been edited by PK2: 31 January 2012 - 10:34

[John Mason]

They list one possible candidate: "The first of these periods saw four large volcanic eruptions beginning in 1256, probably from the tropics sources, although the exact locations have not been determined. The later period incorporated the major Kuwae eruption in Vanuatu."

You need tropical eruptions of enough power to blast debris and gases to high above the troposphere to accomplish this, is the gist of what they are saying. There are several candidate volcanic provinces to think of: the African Rift Valley; the Pacific "Ring of Fire"; Mexico being among them.

Cheers - John

[skanky]

The volcano link is not new (as usual this is research that's building on previous research). The first I read of it was at BA, but he's essentially channelling Caspar Ammann: http://blogs.discove...-a-new-ice-age/

NB scroll to Jet vs The Volcano for the relevant bit.

I'm sure, based on that, that a Google Scholar search will pull up a lot of relevant papers in this area.

[Bazmundo]

Rumblings from the Vulcans on this one, seems Dr Klemetti doesn't like people at least cross-referencing appropriate eruptions without laying blame at their door. Though it must be said he's giving out more caveats than usual, especially with respect to SO₂ and lesser eruptions, namely the Icelandics:

http://www.wired.com...gun/#more-94336

As the comments begin, the plot thickens as Laki and Tambora were at the end of the LIA!

[skanky]

Interview with lead author on this week's Material World: http://www.bbc.co.uk...rammes/b006qyyb

[ldavidcooke]

Hey All,

I suspect that climate has certain temperature/humidity correlations depending on the dominate driver of climate varibility at the time. Generally, this would suggest that though there are multiple drivers, long term synoptic variation or multi-decadal weather patterns are based on the balance of multiple factors, which can come either in sequential or random cycles. Specifically, normal ENSO drift following solar cycles, with a abnormal cross zonal convective flow which occurs roughly every 7 years with multiples of that value having extremes or peaks.

Eventually, the energy rebalances and the dominate synoptic driver resets. In the meantime, I suspect certain abnormal events can disrupt normal patterns, such as large meteor strikes, tsunamis/earthquakes, or volcanos. (Though the latter two could be driven by changes in radiative heat flow from Earths core into space.)

That volcanos can participate in synoptic patterns is well established. However, the level of energy would have to be extreme. As to SO2 influence, it would require more then a few months totaling up to the equivalent of a VEI 6-7 eruption. Though if you added several cubic km of very fine ash to the tropopause it could change albedo and precipitation aerosols. I suspect that it would require that a combination of normal multi-decadal pattern drivers being enhanced by an extreme event. Which in turn drives a reinforcing event.

[kvet]

This site's interesting-at least you can compare the period in question with app. 11,000 years of vulcanism . Just how major vulcanism was in that period is difficult to say. All I know is that since Pinatubo we've been rather lucky, and I suspect we are well overdue for a big bang. http://www.volcano.s...m?sortorder=asc

[andre]

Just read the article. This is the essential paragraph (page 3, par 13):

Quote

[13] [13] Volcanism exerts strong negative radiative forcing [Robock, 2000] that could easily explain the observed rapid snowline lowering, but the short residence time of stratospheric sulfate aerosols precludes a lasting influence on the regional energy balance from a single eruption. Decadally paced eruptions may produce greater cooling than a single large eruption if the recurrence interval is shorter than the upper ocean temperature relaxation time of decades [Schneider et al., 2009]. This may explain multidecadal cold episodes, but many Canadian sites that became ice-covered
1275 AD and 1450 AD, following episodes of strong explosive volcanism, remained continuously ice-covered until the most recent decade (Figure 2c). Such a long-lasting response suggests that explosive volcanism must have engaged a substantial and largely self-sustaining positive feedback(s).

I can see the logic. Would the 100ky ice age cycle also be triggered by something like this?

Disclaimer. No CO2 here.

[Bluenosejohn]

In 2005 the BBC broadcast one of their first class Timewatch programmes on 1816 called the Year Without Summer. It showed the effect on the World of the Tambora volcanic eruption of 1815. I cannot see a link on the web that plays for this unfortunately and unless the BBC decide to show it on BBC4 one day it is unlikely to appear on one of the various satellite history channels as it makes no mention of the Nazis....

There are plenty of other references to the effects of this on the net however. The link below gives an indepth report on its effect on New England for example

http://www.islandnet...istory/1816.htm

The 2010 eruption of Eyjafjallajokull was followed by the cold winter of 2010/11 so there may be something in it which makes the potential of Katla in Iceland a worry for those of us who do not own energy company shares.

http://www.bbc.co.uk...europe-15995845

[Bazmundo]

This really seems to have disturbed the blogosphere's favourite Volcanologist. Some good candidates listed though.

http://www.wired.com...on-of-1258-a-d/

[andre]

This may be big. I mean a few volcanoes for a little ice age. A lot of volconoes for a big ice age. Notice from my beloved Hubberten et al 2004:

Quote

.Inversed modelling based on these results shows that a progressive cooling which started around30 ka 14C BP, caused ice growth in Scandinavia and the northwestern areas of the Barents–Kara Sea shelf, due to a maritime climate with relatively high precipitation along the western flank of the developing ice sheets.

But what caused that Last Glacial Maximum cooling? Bay et al 2006: Notice in Fig 3 a significant increase in volcanic markers after 32Ka (28K 14C BP). This can also be seen in the volcanic tracer data of the GISP-II ice core between 33,092 and 32,851 years ago, and again later around 28,600 and 27,900 some century of strong volcanism each time.

[Bazmundo]

Often alluded to, and wrt to the LIA (~1500 onwards), there are theories other than just volcanic effects. One such getting recent rejuvenation:

http://www.physorg.c...ce-age-due.html

[NileQueen]

Andy Mayhew, on 31 January 2012 - 10:18, said:

Recent volcanic activity hasn't been anywhere near enough to affect climate - and eruptions also need to be near the equator to have any global effect. The last such was Pinatubo. But an interest bit of research there, thanks for flagging it up. See also:

http://www.scienceda...20130131509.htm

No mention though of which volcanoes. I'm guessing therefore that at this stage it's pure speculation, until we find the smoking caldera ....

It's not just the volcanism Andy. It seems that a series of large explosive volcanic events can set up feedbacks that cause sea ice to persist. This in
turns shuts down the NA ocean heat conveyor.


Geophysical Research Letters, Vol 39.

Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks,
by Gifford H. Miller, Aslaug Geirsdottir, Yafang Zhong, Darren Larsen, Bette Otto-Bliesner, Marika Holland, David Bailey, Kurt Refsnider,
Scott Lehman, John Southon, Chance Anderson, Helgi Bjornsson, and Thorvaldur Thordarson.

By acquiring a collection of radiocarbon dates on plants that were overrun by glaciers during the LIA, it was determined
that ice growth began abruptly between 1275 and 1300 AD, followed by a substantial intensification 1430 to 1455 AD.
These intervals of sudden ice growth coincide with two of the most volcanically perturbed half centuries of the past 1000 years.

Just consider if we have another series of volcanic events, how that would affect climate. The question is, what triggered that volcanism?

[NileQueen]

Bazmundo, on 10 February 2012 - 23:02, said:

Often alluded to, and wrt to the LIA (~1500 onwards), there are theories other than just volcanic effects. One such getting recent rejuvenation:

http://www.physorg.c...ce-age-due.html

Reforestation would have been much later compared to the 1275-1300 ice advance...Columbus hadn't arrived yet.

[NileQueen]

I'm getting a Forbidden notice when I try to reply on one of the recent posts.

So if a series of explosive volcanic eruptions is in fact the trigger to LIA, can we find evidence of a series of explosive volcanic eruptions for the Younger Dryas?
And for ice ages back through the Pleistocene? I'm going to hypothesize that impactors could be one mechanism for triggering the volcanism.

[NileQueen]

NileQueen, on 11 February 2012 - 17:55, said:

It's not just the volcanism Andy. It seems that a series of large explosive volcanic events can set up feedbacks that cause sea ice to persist. This in
turns shuts down the NA ocean heat conveyor.


Geophysical Research Letters, Vol 39.

Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks,
by Gifford H. Miller, Aslaug Geirsdottir, Yafang Zhong, Darren Larsen, Bette Otto-Bliesner, Marika Holland, David Bailey, Kurt Refsnider,
Scott Lehman, John Southon, Chance Anderson, Helgi Bjornsson, and Thorvaldur Thordarson.

By acquiring a collection of radiocarbon dates on plants that were overrun by glaciers during the LIA, it was determined
that ice growth began abruptly between 1275 and 1300 AD, followed by a substantial intensification 1430 to 1455 AD.
These intervals of sudden ice growth coincide with two of the most volcanically perturbed half centuries of the past 1000 years.

Just consider if we have another series of volcanic events, how that would affect climate. The question is, what triggered that volcanism?

Abstract is here:
http://www.agu.org.p...1GL050168.shtml

Hopefully you can see it...

This post has been edited by NileQueen: 11 February 2012 - 18:29

[Bazmundo]

NileQueen, on 11 February 2012 - 18:04, said:

Reforestation would have been much later compared to the 1275-1300 ice advance...Columbus hadn't arrived yet.

Indeed, hence the reference to 1500 onwards, whereupon there might have been a substantial increase in ice formation.

NileQueen, on 11 February 2012 - 18:07, said:

I'm getting a Forbidden notice when I try to reply on one of the recent posts.

So if a series of explosive volcanic eruptions is in fact the trigger to LIA, can we find evidence of a series of explosive volcanic eruptions for the Younger Dryas?
And for ice ages back through the Pleistocene? I'm going to hypothesize that impactors could be one mechanism for triggering the volcanism.

You might have tried to post again too soon after posting, there's a delay on the board to stop unfriendly bots.

I think one of the problems with the recent study is the reference to volcanism is no more than implied, there aren't any definite candidates or 'smoking guns' according to the volcanologists. A very bulky Tropical eruption is required to coat both poles. It might not be as clear cut as is being suggested if the dates/volumes of eruption(s) can't be fine tuned. From here, surely we can assume no more credence to the theory?

[NileQueen]

Bazmundo, on 11 February 2012 - 20:20, said:

Indeed, hence the reference to 1500 onwards, whereupon there might have been a substantial increase in ice formation.



You might have tried to post again too soon after posting, there's a delay on the board to stop unfriendly bots.

I think one of the problems with the recent study is the reference to volcanism is no more than implied, there aren't any definite candidates or 'smoking guns' according to the volcanologists. A very bulky Tropical eruption is required to coat both poles. It might not be as clear cut as is being suggested if the dates/volumes of eruption(s) can't be fine tuned. From here, surely we can assume no more credence to the theory?

Bazmundo, were you able to read the Miller et al 2012 paper? See Fig. 2b for the sulfate peaks in ice core records.
The reference is certainly not just implied. They use global stratospheric sulfate aerosol loadings from Gao et al, 2008.

Gao, C., A.Robock, and C. Ammann. 2008. Volcanic forcing of climate over the past 1500 years: An improved ice core-based index
for climate models. Journal of Geophysical Research. 113. D23111, doi: 10.1029/2008JD010239.

Mike Baillie was trying to match those sulfate spikes in the ice cores to tree ring series and had some luck with it.

This post has been edited by NileQueen: 11 February 2012 - 21:04