volcanic eruptions and the atmosphere

Question 1

Name three gas or volatile species emitted into the atmosphere by volcanic eruptions

Answer 1

Carbon dioxide
Sulphur dioxide
Water vapour
Hydrogen sulphide
Hydrogen chloride

Question 2

Why did temperatures in the stratosphere increase after the large explosive eruption of Mt. Pinatubo in 1991?

Answer 2

During the eruption, volcanic sulphur dioxide (SO2) was emitted high into the stratosphere where it was converted to form sulphuric acid aerosol particles. Volcanic sulphuric acid aerosol particles can alter the radiative balance of Earth due to their ability to scatter and absorb radiation. In the stratosphere temperatures increased following the eruption because the sulphuric acid aerosol particles absorbed outgoing thermal infrared radiation.

Question 3

What was emitted high into the atmosphere after the eruption of Mt. Pinatubo

Answer 3

sulphur dioxide which as converted into sulphuric acid aerosol particles

Question 4

what type of radiation can sulphuric acid aerosol particles absorb

Answer 4

outgoin thermal infrared radiation

Question 5

1. Why is there no linear relationship between surface temperature cooling and the mass of sulphur dioxide (SO2) emitted by volcanic eruptions?

Answer 5

There is no linear relationship between surface temperature change and the mass of SO2 emitted because following conversion of SO2 to sulphuric acid aerosol, these particles grow and coagulate (or aggregate) to larger sizes for successively larger SO2 emissions. Particles with diameters greater than 0.5 microns fall out of the atmosphere faster than smaller particles, and large particles reflect solar radiation back to space less efficiently than smaller-sized particles.

Question 6

what is the lifetime of volcanic aerosol particles in the stratosphere

Answer 6

1-3 years

Question 7

what is the lifetime of volcanic aerosol particles in the troposphere

Answer 7

days to weeks