THE AVAILABILITY OF H2O2 AND O-3 FOR AQUEOUS PHASE OXIDATION OF SO2 - THE QUESTION OF LINEARITY

Gas phase hydrogen peroxide measurements were made at two mountaintop sites in the eastern U.S. Calculations performed for cloud and gas phase conditions typical of those found at the summits of Whiteface and Whitetop Mountains during the summer months indicated that oxidation of dissolved SO2 by H2O2 proceeds at a rate almost three orders of magnitude faster than oxidation by ozone. An examination of the clear-air [SO2] [H2O2] ratios provided an estimate of the degree of nonlinearity that should be anticipated in these areas. This ratio was found to exceed unity most of the hours during the monitoring periods at both sites. The [SO2] [H2O2] ratio was found to vary seasonally and spatially with fall ratios exceeding summer and higher ratios were measured at the southern site. © 1990.