Volcanoes Flashcards
Volcanoes effect radiative forcing, what is this?
Change imposed on planetary radiation, which alters temperatures
What is positive radiative forcing?
Increased energy in the system, results in warming
What is negative radiative forcing?
Decreased energy in the system, resulting on cooling
Volcanic climatic impacts depend upon what?
Stratospheric injection of aerosols
What 3 things affect how a volcano effects the climate?
Explosivity
Sulphur content in Magna
Location
What is VEI and how will it affect climate?
Volcanic explosivity index
A VEI of +5 is more likely to impact climate
How does location determine climatic effects?
Polar regions have a decreasing stratospheric height (8km) making it easier for aerosols to enter the stratosphere
Lower latitudes (equator) means aerosols are easier to spread and have a wider impact
What is ejected by a volcano?
Particulates (ash, which doesn’t stay for long)
GHG (which warm the planet)
Sulphur (has a long residency time)
What are the effects of sulphur gets into the stratosphere?
It absorbs incoming shortwave solar radiation, as well as outgoing longwave radiation
This causes cooling at earth’s surface and heating in the stratosphere
Where is cooling most pronounced?
In the low latitudes (as this area gets most incoming SW radiation)
1991 anomaly of temperature description
Sulphate aerosols sped up our jet stream, meaning temperatures in the northern hemisphere were hotter whilst the rest of the globe cooled
How can we identify past eruptions?
Tree rings
Ice cores
Toba Eruption Info
73,000 years ago
Caused a volcanic winter lasting 7/8 years
Tambora eruption info
1815, caused the 1816 year without summer
0.7c decrease in temperature
VEI of 7
