Volcanoes & Climate

Climate and Global Change Notes

15-1

Volcanoes & Climate

Volcanic Activity

Effect on Climate

Mt. Pinatubo

Science Concepts

SO2 Effect

The Earth System (Kump, Kastin & Crane)

• Chap. 15 (pp. 299-302)


15-2

The Earth’s Climate System

Stratospheric

Chemistry/

Dynamics

OceanDynamic

s

TerrestrialEnergy/Moisture

Global Moisture

Marine/Biogeochemistry

External Forcing

CO2

Sun

Volcanoes

Soil

Climate

Change

Atmospheric Physics/Dynamics

LandUse

CO2

Pollu-tants

Tropospheric Chemistry

HumanActivities

TerrestrialEcosystems

Biogeochemical Systems

Physical Climate Systems

Human Forcing


15-3

Volcanoes & Climate

Ben Franklin Observation

• Benjamin Franklin was serving the United States as an ambassador to France and living in Paris when Laki volcano in Iceland erupted

During several of the summer months of the year 1783, when the effect of the sun’s rays to heat the earth in these northern regions should have been greatest, there existed a constant fog over all Europe, and great part of North America. This fog was of a permanent nature; it was dry, and the rays of the sun seemed to have little effect towards dissipating it, as they easily do a moist fog, arising from water. They were indeed rendered so faint in passing through it, that when collected in the focus of a burning glass, they would scarce kindle brown paper. Of course, their summer effect in heating the earth was exceedingly diminished.

Hence the earth was early frozen,Hence the first snows remained on it unmelted, and

received continual additions.Hence the air was more chilled, and the winds more

severely cold.Hence perhaps the winter of 1783-4, was more severe, than

any that had happened for many years.


15-4

Volcanoes & Climate

Ben Franklin Observation (Con’t)

The cause of this universal fog is not yet ascertained. Whether it was adventitious to this earth, and merely a smoke, proceeding from the consumption by fire of some of those great burning balls or globes which we happen to meet within our rapid course round the sun, and which are sometimes seen to kindle and be destroyed in passing our atmosphere, and whose smoke might be attracted and retained by our earth; or whether it was the vast quantity of smoke, long continuing to issue during the summer from Hecla in Iceland, and that other volcano which arose out of the sea near that island, which smoke might be spread by various winds, over the northern part of the world, is yet uncertain.

Franklin, B., Meteorological imaginations and conjectures, Manchester Literary and Philosophical Society Memoirs and Proceedings, 2, 122, 1784. [Reprinted in Weatherwise, 35, p. 262, 1982.]


15-5

Volcanoes & Climate

• National Public Radio story - “How a Volcano Eruption Wiped Away Summer”

by Michael Sullivan 10/22/07http://www.npr.org/templates/story/story.php?storyId=15448607

“Darkness” By Lord ByronI had a dream, which was not all a dream.

The bright sun was extinguish'd, and the starsDid wander darkling in the eternal space,Rayless, and pathless, and the icy earth

Swung blind and blackening in the moonless air;Morn came and went—and came, and brought no day,

And men forgot their passions in the dreadOf this their desolation; and all hearts

Were chill'd into a selfish prayer for light:And they did live by watchfires—and the thrones,

The palaces of crowned kings—the huts,. . .• Written summer of 1816 when Percy Bysshe Shelley, his wife Mary

Wollstonecraft Shelley (wrote novel “Frankenstein”), and their friend Lord Byron

went to Lake Geneva, Switzerland for their summer holiday.• Tambora in Indonesia erupted in 1815 and produced the “Year Without a

Summer” (1816)


15-6

Volcanoes & Climate

1960-1995 Volcanic Activity

• Red triangles indicate volcanoes

http://svs.gsfc.nasa.gov/vis/a000000/a000100/a000155/index.html


15-7

Volcanic Global Cooling • Volcanoes eject sulfur dioxide (SO2) and other gases during eruptions • SO2 combines and H2O in the stratosphere to form fine droplets or “aerosols”

of sulfuric acid (H2SO4) that form a haze• Haze increases the atmospheric albedo, thus reducing the solar energy

reaching the Earth’s surface

• Example: - Mt Tambora in

Indonesia (1815)- 1816 - Year without

a summer- June snows; frost

in July and August in the northeast

- New England temperatures cooler than normal; 2-4°C in July; 1-2°C in August

- Caused 80% reduction in harvest

Volcanoes & Climate

http://www-sage3.larc.nasa.gov/solar/learning-aerosol.html


15-8

Tree-Ring Width Vs Year of Eruption

• Growth index for the 24 largest volcanoes

Temperature Vs Year of Eruption

• Composite global surface temperature change near the time of the five volcanoes producing the greatest optical depths since 1880: Krakatau (1883), Santa Maria (1902), Agung (1963), El Chichon (1982) and Pinatubo (1991)

Volcanoes & Climate

http://www.giss.nasa.gov/research/intro/hansen_02/


15-9

Estimated Effects of Volcanoes

Volcano Latitude Date DT (°C)St. Helens 46°N 1980 <0.1Agung 8°S 1963 <0.05El Chichon 17°N 1982 <0.4Krakatau 6°S 1883 0.3Tambora 8°S 1815 0.5Toba 3°N 7,000 B.P. large?Laki 64°N 1783-84 1.0?Roza 47°N 4,000 B.P. large?

Volcanoes & Climate


15-10

Erupted 9 June 1991 After Several Hundred Years of Inactivity

• Description- Location: Philippines - Latitude: 15.13 N, Longitude: 120.35 E

- Height: 1,745 meters before June 15, 1991 eruption

- Height: 1,485 meters (high point caldera rim) after

eruption- Second in size to eruption of Katmai,

Alaska (1912) - Ten times larger than Mt St. Helens

eruption in 1980- Ash cloud rose 30- 35 km into the sky

Mt. Pinatubo

QuickTime™ and aGIF decompressor

are needed to see this picture. QuickTime™ and aGIF decompressor

are needed to see this picture.

http://www.volcano.si.edu/gvp/usgs/maps.cfm#philippines

http://vulcan.wr.usgs.gov/Volcanoes/Philippines/Pinatubo/images.html


15-11

Mt. Pinatubo

Mt. Pintatubo Eruption - June 1991


http://hannover.park.org/Philippines/pinatubo/


15-12

Mt. Pinatubo

Mt. Pintatubo Ash at Clark Air Force Base



are needed to see this picture.


are needed to see this picture.Spread of Mt.

Pintatubo Ash and Gases


15-13

Mt. Pinatubo

Nimbus-7 Sulfur Dioxide

June 17 June 19

http://eospso.gsfc.nasa.gov/eos_edu.pack/p35.html


15-14

Mt. Pinatubo

Nimbus-7Sulfur Dioxide

June 16

June 19

June 22

June 25


15-15

Mt. Pinatubo

SAGE II 1020 m Stratospheric Optical Depth

15 Apr- 25 May 1991

14 Jun- 26 Jul 1991

13 Feb- 26 Mar 1993

http://www-sage2.larc.nasa.gov/introduction/


15-16

Volcanoes & Climate

Volcanic Eruptions

• Atmospheric SO2 detectedby TOMS per volcanosince 1979

http://rst.gsfc.nasa.gov/Sect16/Sect16_2.html


15-17

Volcanoes & Climate

SAGE II1020 mStrato-sphericOpticalDepth

X St. Helens◊ El Chichon ∆ Ruiz i Pinatubo

o Xelui + Hudson1979198119831985198719891991199319951997>2x 10-1<10-310-210-180°N60°N40°N20°NEQ20°S40°S60°S80°S

http://www-sage2.larc.nasa.gov/introduction/

Volcanoes & Climate

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