Sulphur Cycle

Question 1

Sulfate

Answer 1

SO4

Question 2

volatile hydrogen sulfide

Answer 2

H2S

Question 3

The Sulfur Cycle: Atmospheric Sulfur

Answer 3

• Atmosphere contains SO2, H2S and sulfate particles that combine with moisture & are removed with precipitation (wet deposition)
• Sulfate particles may also fall to the Earth’s surface as dry deposition
• H2S quickly oxidizes to sulfur dioxide (SO2).
• Atmospheric SO2 joins with moisture to form weak sulfuric acid, H2SO4
• Oceans are a source of aerosols (small particles dispersed in the air) that contain sulfate

Question 4

Atmospheric-Ocean Sulfur: DMS

Answer 4

• Dimethylsulfide (DMS) is a major biogenic gas (biological formation) that enters the atmosphere from the ocean
• Created from decomposition of plankton (algae) in ocean surface waters
• DMS is oxidized to sulfate aerosols which are involved in the formation of cloud condensation nuclei (water droplets)
• Clouds have a pronounced effect on climate (cooling effect)
• Therefore, DMS production may provide a partial solution to offset global warming