Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (685 KB)

Title: Sulfur dioxide reactions on ice surfaces: Implications for dry deposition to snow

Author: Conklin, Martha H.; Sommerfeld, Richard A.; Laird, S. Kay; Villinski, John E.;

Date: 1993

Source: Atmospheric Environment. 27A(2): 159-166.

Publication Series: Scientific Journal (JRNL)

Description: Controlled exposure of ice to a reactive gas, SO2, demonstrated the importance of the chemical composition of the ice surface on the accumulation of acidity in snow. In a series of bench-scale continuous-flow column experiments run at four temperatures (-1, -8, -30 and -60°C), SO2 was shown to dissolve and to react with other species in the ice-air interfacial region at temperatures approaching the melting point of ice. Experiments consisted of passing air containing SO2 through glass columns packed with 100-ìm ice spheres of varying bulk composition (0-5 ìM H2O2, and 0-1 mM NaCl), and analysing SO2 in the air and SO42- in the ice. At all temperatures (-60 to -1°C), increased retention volumes were found for increasing ionic strength and oxidant concentration. At the coldest temperatures and with no NaCl, increased retention volumes for -60 vs -30°C are consistent with SO2 uptake by physical adsorption. At warmer temperatures, -8 and -1°C, the observed tailing in the sorption curves indicated that other processes besides physical adsorption were occurring. The desorption curves showed a rapid decrease for the warmer temperatures, indicating the sorbed SO2 is irreversibly oxidized to SO42-. Results indicate that aqueous-phase reactions can occur below -8°C (i.e. -30 and -60°C). Results for different salt concentrations show that increasing ionic strength facilitates SO2 oxidation at colder temperatures, which is consistent with freezing point depression. One environmental implication is that snowpacks in areas with background SO2, can accumulate acidity during the winter months. As acidity accumulates, the solubility of SO2 will decrease causing a concomitant decrease in the air-to-surface flux of SO2. Modeling dry deposition of gases to snow surfaces should incorporate the changing composition of the ice surface.

Keywords: sulfur dioxide, ice, snow

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

XML: View XML

Citation:


Conklin, Martha H.; Sommerfeld, Richard A.; Laird, S. Kay; Villinski, John E. 1993. Sulfur dioxide reactions on ice surfaces: Implications for dry deposition to snow. Atmospheric Environment. 27A(2): 159-166.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.