Incorporation of sulfur dioxide into snow and depositing ice

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6586784

Valdez, M P

Depth profiles of S(IV) and S(VI) in snow exposed to 20-140 ppbv SO/sub 2/ for 6 to 12 hours were determined in 48 laboratory experiments. Surface deposition velocity (V/sub d/) averaged 0.06 cm s/sup -1/. Well-metamorphosed snow, longer run times, higher SO/sub 2/ concentrations and colder snow were associated with lower values of V/sub d/, and vice versa. Melting followed by draining increased v/sub d/ greatly (0.14 cm s/sup -1/). Any effect of ozone on SO/sub 2/ v/sub d/ was undetectable. Most sulfur in the snow was a S(VI), even without added ozone, indicating the presence of other oxidants, especially in new snow. The deposition of SO/sub 2/ into a snowpack is modeled as an aqueous system, where the liquid water is considered to be present on snow grain surfaces. Gas transport into the snow, air-water partitioning,and aqueous-phase reactions are explicitly considered. Experiments were also conducted on the incorporation of SO/sub 2/ into ice depositing from the vapor at -7 and -15/sup 0/C. Remarkably, SO/sub 2/ is captured in deposited ice at concentrations comparable to Henry's Law equilibrium with water at 0/sup 0/C. Ozone and HCHO appear to inhibit, not enhance, SO/sub 2/ capture. An aqueous-film model accounting for the capture of SO/sub 2/ by depositing ice was developed.

• Research Organization: Arizona Univ., Tucson (USA)
• OSTI ID: 6586784
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
510200 -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC PRECIPITATIONS
CHALCOGENIDES
DEPOSITION
ENVIRONMENTAL TRANSPORT
ICE
MASS TRANSFER
OXIDES
OXIDIZERS
OXYGEN COMPOUNDS
POLLUTION
SNOW
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES